feat(l4d2-web): managed global map overlays with daily refresh

Adds two managed system overlays (l4d2center-maps, cedapug-maps) that fetch curated map archives from upstream sources and reconcile addons symlinks for non-Steam maps. A daily systemd timer enqueues a coalesced refresh_global_overlays worker job; downloads, extraction, and rebuilds run in the existing job worker and surface in the job log UI. Schema: GlobalOverlaySource / GlobalOverlayItem / GlobalOverlayItemFile plus nullable Job.user_id so system jobs render as "system" in the UI. The new builder reconciles symlinks against the per-source vpk cache and leaves foreign symlinks untouched. Initialize-time guard refuses to mount a partial overlay if any expected vpk is missing from cache. Refresh service uses shutil.move to handle EXDEV when /tmp and the cache live on different filesystems. Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-08 08:05:14 +02:00 · 2026-05-08 08:05:14 +02:00 · 92d6ebbe82
commit 92d6ebbe82
parent 4f78574edd
39 changed files with 4770 additions and 28 deletions
--- a/deploy/README.md
+++ b/deploy/README.md
@ -14,6 +14,7 @@ The deployment uses these paths:
 - `/var/lib/left4me/installation`: shared L4D2 installation.
 - `/var/lib/left4me/overlays`: overlay directories. External (admin-managed) overlays still live at any relative path under here; new overlays created through the web UI use `${overlay_id}` as their path.
 - `/var/lib/left4me/workshop_cache`: deduplicated cache of `.vpk` files downloaded for workshop overlays. One file per Steam item, named `{steam_id}.vpk`. Workshop overlays symlink into this tree.
+- `/var/lib/left4me/global_overlay_cache`: cache of non-Steam map archives and extracted `.vpk` files used by managed global map overlays.
 - `/var/lib/left4me/instances`: rendered instance specifications and per-instance state.
 - `/var/lib/left4me/runtime`: per-instance runtime mount directories.
 - `/var/lib/left4me/tmp`: temporary files used by deployment/runtime operations.
@ -41,6 +42,10 @@ deploy/deploy-test-server.sh deploy-user@example-host

 The SSH user must be able to run `sudo` on the target host. The deployment configures system packages, directories, environment files, helper scripts, sudoers rules, Python dependencies, and systemd units.

+## Scheduled Jobs
+
+`left4me-refresh-global-overlays.timer` runs daily with `Persistent=true`. It invokes `flask refresh-global-overlays`, which only enqueues a `refresh_global_overlays` job; downloads and rebuilds run in the web worker and are visible in the normal job log UI.
+
 ## Admin Bootstrap

 Set the bootstrap credentials in the environment when creating the first admin user:
--- a/deploy/deploy-test-server.sh
+++ b/deploy/deploy-test-server.sh
@ -97,6 +97,7 @@ $sudo_cmd mkdir -p \
    /var/lib/left4me/instances \
    /var/lib/left4me/runtime \
    /var/lib/left4me/workshop_cache \
+    /var/lib/left4me/global_overlay_cache \
    /var/lib/left4me/tmp

 $sudo_cmd chown left4me:left4me \
@ -106,6 +107,7 @@ $sudo_cmd chown left4me:left4me \
    /var/lib/left4me/instances \
    /var/lib/left4me/runtime \
    /var/lib/left4me/workshop_cache \
+    /var/lib/left4me/global_overlay_cache \
    /var/lib/left4me/tmp
 $sudo_cmd chown -R left4me:left4me /opt/left4me

@ -124,6 +126,8 @@ $sudo_cmd chown -R left4me:left4me /opt/left4me

 $sudo_cmd cp /opt/left4me/deploy/files/usr/local/lib/systemd/system/left4me-web.service /usr/local/lib/systemd/system/left4me-web.service
 $sudo_cmd cp /opt/left4me/deploy/files/usr/local/lib/systemd/system/left4me-server@.service /usr/local/lib/systemd/system/left4me-server@.service
+$sudo_cmd cp /opt/left4me/deploy/files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.service /usr/local/lib/systemd/system/left4me-refresh-global-overlays.service
+$sudo_cmd cp /opt/left4me/deploy/files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.timer /usr/local/lib/systemd/system/left4me-refresh-global-overlays.timer
 $sudo_cmd cp /opt/left4me/deploy/files/usr/local/libexec/left4me/left4me-systemctl /usr/local/libexec/left4me/left4me-systemctl
 $sudo_cmd cp /opt/left4me/deploy/files/usr/local/libexec/left4me/left4me-journalctl /usr/local/libexec/left4me/left4me-journalctl
 $sudo_cmd chmod 0755 /usr/local/libexec/left4me/left4me-systemctl /usr/local/libexec/left4me/left4me-journalctl
@ -176,6 +180,7 @@ fi
 $sudo_cmd systemctl daemon-reload
 $sudo_cmd systemctl enable --now left4me-web.service
 $sudo_cmd systemctl restart left4me-web.service
+$sudo_cmd systemctl enable --now left4me-refresh-global-overlays.timer
 for attempt in 1 2 3 4 5 6 7 8 9 10; do
    if curl -fsS http://127.0.0.1:8000/health; then
        exit 0
--- a/deploy/files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.service
+++ b/deploy/files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.service
@ -0,0 +1,17 @@
+[Unit]
+Description=left4me refresh global map overlays
+After=network-online.target left4me-web.service
+Wants=network-online.target
+
+[Service]
+Type=oneshot
+User=left4me
+Group=left4me
+WorkingDirectory=/opt/left4me
+Environment=HOME=/var/lib/left4me
+Environment=PATH=/opt/left4me/.venv/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
+EnvironmentFile=/etc/left4me/host.env
+EnvironmentFile=/etc/left4me/web.env
+ExecStart=/opt/left4me/.venv/bin/flask --app l4d2web.app:create_app refresh-global-overlays
+ProtectSystem=full
+ReadWritePaths=/var/lib/left4me
--- a/deploy/files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.timer
+++ b/deploy/files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.timer
@ -0,0 +1,10 @@
+[Unit]
+Description=Daily left4me global map overlay refresh
+
+[Timer]
+OnCalendar=daily
+Persistent=true
+Unit=left4me-refresh-global-overlays.service
+
+[Install]
+WantedBy=timers.target
--- a/deploy/tests/test_deploy_artifacts.py
+++ b/deploy/tests/test_deploy_artifacts.py
@ -9,6 +9,8 @@ DEPLOY = ROOT / "deploy"

 WEB_UNIT = DEPLOY / "files/usr/local/lib/systemd/system/left4me-web.service"
 SERVER_UNIT = DEPLOY / "files/usr/local/lib/systemd/system/left4me-server@.service"
+GLOBAL_REFRESH_SERVICE = DEPLOY / "files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.service"
+GLOBAL_REFRESH_TIMER = DEPLOY / "files/usr/local/lib/systemd/system/left4me-refresh-global-overlays.timer"
 SYSTEMCTL_HELPER = DEPLOY / "files/usr/local/libexec/left4me/left4me-systemctl"
 JOURNALCTL_HELPER = DEPLOY / "files/usr/local/libexec/left4me/left4me-journalctl"
 SUDOERS = DEPLOY / "files/etc/sudoers.d/left4me"
@ -203,3 +205,25 @@ def test_deploy_script_runs_migrations_before_app_initialization() -> None:

 def test_deploy_script_shell_syntax() -> None:
    subprocess.run(["sh", "-n", str(DEPLOY_SCRIPT)], check=True)
+
+
+def test_global_refresh_timer_units_exist_and_enqueue_only():
+    service = GLOBAL_REFRESH_SERVICE.read_text()
+    timer = GLOBAL_REFRESH_TIMER.read_text()
+
+    assert "User=left4me" in service
+    assert "EnvironmentFile=/etc/left4me/host.env" in service
+    assert "EnvironmentFile=/etc/left4me/web.env" in service
+    assert "flask --app l4d2web.app:create_app refresh-global-overlays" in service
+    assert "OnCalendar=daily" in timer
+    assert "Persistent=true" in timer
+    assert "WantedBy=timers.target" in timer
+
+
+def test_deploy_script_installs_and_enables_global_refresh_timer():
+    script = DEPLOY_SCRIPT.read_text()
+
+    assert "/var/lib/left4me/global_overlay_cache" in script
+    assert "left4me-refresh-global-overlays.service" in script
+    assert "left4me-refresh-global-overlays.timer" in script
+    assert "systemctl enable --now left4me-refresh-global-overlays.timer" in script
--- a/docs/superpowers/plans/2026-05-07-l4d2-global-map-overlays.md
+++ b/docs/superpowers/plans/2026-05-07-l4d2-global-map-overlays.md
--- a/docs/superpowers/specs/2026-05-07-l4d2-global-map-overlays-design.md
+++ b/docs/superpowers/specs/2026-05-07-l4d2-global-map-overlays-design.md
@ -0,0 +1,353 @@
+# L4D2 Global Map Overlays Design
+
+**Goal:** Add two managed, system-wide map overlays, `l4d2center-maps` and `cedapug-maps`, populated from upstream map sources and refreshed daily through the existing job system.
+
+**Approval status:** User-approved design direction. Implementation must not start until this spec is reviewed and an implementation plan is written.
+
+## Context
+
+`left4me` already has typed overlays, a builder registry, global overlays through `Overlay.user_id = NULL`, and queued overlay build jobs. Steam Workshop overlays use a cache plus symlinks into `left4dead2/addons/`, and server initialization already runs overlay builders before calling `l4d2ctl initialize`.
+
+Global map sources fit the same model. The host library remains unchanged: it receives overlay refs and mounts directories. The web app owns map-source fetching, cache management, reconciliation, and job logs.
+
+The two upstream sources are:
+
+- `https://l4d2center.com/maps/servers/index.csv`
+- `https://cedapug.com/custom`
+
+## Locked Decisions
+
+1. **One general operation.** Use `refresh_global_overlays`, not source-specific cron operations.
+2. **Systemd owns time.** A systemd timer runs daily and invokes a Flask CLI command. The CLI only enqueues work; the existing worker performs downloads and writes logs.
+3. **System jobs are nullable-owner jobs.** `jobs.user_id` becomes nullable. `NULL` means the job was created by the system. UI displays owner as `system`. Only admins can access system jobs.
+4. **Managed global overlays are auto-seeded.** The app creates or repairs exactly one `l4d2center-maps` overlay and exactly one `cedapug-maps` overlay.
+5. **Global overlays are normal system overlays for users.** `Overlay.user_id = NULL` makes them visible to every authenticated user and selectable in every user's blueprint editor.
+6. **Managed types are not user-creatable.** Normal overlay creation does not offer `l4d2center_maps` or `cedapug_maps`. The seeder is the only code path that creates those types.
+7. **Exact reconciliation.** Refresh makes each managed overlay match its upstream manifest. Removed upstream maps are removed from the managed overlay symlink set. Foreign files are left alone and logged.
+8. **No initialize-time downloads.** `initialize_server()` may run builders to repair symlinks, but it must not fetch remote manifests or download large archives. Missing cache content fails clearly.
+9. **Separate cache from Workshop.** Non-Steam global maps use `${LEFT4ME_ROOT}/global_overlay_cache`, not `${LEFT4ME_ROOT}/workshop_cache`.
+10. **Source-specific parsing stays explicit.** Do not introduce a generic arbitrary HTTP source framework in this phase.
+
+## Architecture
+
+The design extends the existing overlay-builder registry:
+
+```python
+BUILDERS = {
+    "external": ExternalBuilder(),
+    "workshop": WorkshopBuilder(),
+    "l4d2center_maps": GlobalMapOverlayBuilder(),
+    "cedapug_maps": GlobalMapOverlayBuilder(),
+}
+```
+
+Both global map overlay types share the same filesystem builder. Source-specific code lives in refresh services that know how to fetch and parse upstream manifests.
+
+High-level flow:
+
+```text
+systemd timer
+  -> flask refresh-global-overlays
+     -> ensure_global_overlays()
+     -> enqueue refresh_global_overlays job (coalesced)
+        -> worker fetches manifests
+        -> worker downloads/extracts cache files
+        -> worker records desired VPK files
+        -> worker rebuilds overlay symlinks directly
+```
+
+Auto-seeded overlay rows use fixed names, managed types, `user_id = NULL`, and web-generated paths:
+
+```text
+name=l4d2center-maps, type=l4d2center_maps, user_id=NULL, path=str(id)
+name=cedapug-maps, type=cedapug_maps, user_id=NULL, path=str(id)
+```
+
+## Data Model
+
+### `jobs`
+
+Change `jobs.user_id` from required to nullable.
+
+`NULL` means a system-created job. Authorization rules become:
+
+- Admins can view, stream, and cancel every job, including system jobs.
+- Non-admins can access only jobs where `job.user_id == current_user.id`.
+- System jobs are not visible to non-admins through direct job URLs.
+
+Job list/detail pages use outer joins to `users` and render missing owners as `system`.
+
+### `global_overlay_sources`
+
+One row per managed global source overlay:
+
+```text
+id INTEGER PRIMARY KEY
+overlay_id INTEGER NOT NULL UNIQUE REFERENCES overlays(id) ON DELETE CASCADE
+source_key VARCHAR(64) NOT NULL UNIQUE       -- l4d2center-maps | cedapug-maps
+source_type VARCHAR(32) NOT NULL             -- l4d2center_csv | cedapug_custom_page
+source_url TEXT NOT NULL
+last_manifest_hash VARCHAR(64) NOT NULL DEFAULT ''
+last_refreshed_at DATETIME NULL
+last_error TEXT NOT NULL DEFAULT ''
+created_at DATETIME NOT NULL
+updated_at DATETIME NOT NULL
+```
+
+`source_key` is stable and used by the seeder to repair missing rows.
+
+### `global_overlay_items`
+
+One row per manifest item belonging to a global overlay source:
+
+```text
+id INTEGER PRIMARY KEY
+source_id INTEGER NOT NULL REFERENCES global_overlay_sources(id) ON DELETE CASCADE
+item_key VARCHAR(255) NOT NULL               -- stable per source
+display_name VARCHAR(255) NOT NULL DEFAULT ''
+download_url TEXT NOT NULL
+expected_vpk_name VARCHAR(255) NOT NULL DEFAULT ''
+expected_size BIGINT NULL
+expected_md5 VARCHAR(32) NOT NULL DEFAULT ''
+etag VARCHAR(255) NOT NULL DEFAULT ''
+last_modified VARCHAR(255) NOT NULL DEFAULT ''
+content_length BIGINT NULL
+last_downloaded_at DATETIME NULL
+last_error TEXT NOT NULL DEFAULT ''
+created_at DATETIME NOT NULL
+updated_at DATETIME NOT NULL
+UNIQUE(source_id, item_key)
+```
+
+For `l4d2center`, `item_key` and `expected_vpk_name` come from the CSV `Name` column, and `expected_size` / `expected_md5` come from the CSV.
+
+For `cedapug`, `item_key` is the direct download URL path basename, normalized without query parameters. CEDAPUG does not publish checksums in the observed page, so integrity uses HTTP metadata when available and archive extraction checks.
+
+### `global_overlay_item_files`
+
+One row per extracted VPK file that should appear in an overlay:
+
+```text
+id INTEGER PRIMARY KEY
+item_id INTEGER NOT NULL REFERENCES global_overlay_items(id) ON DELETE CASCADE
+vpk_name VARCHAR(255) NOT NULL
+cache_path TEXT NOT NULL                     -- relative path under global_overlay_cache
+size BIGINT NOT NULL
+md5 VARCHAR(32) NOT NULL DEFAULT ''
+created_at DATETIME NOT NULL
+updated_at DATETIME NOT NULL
+UNIQUE(item_id, vpk_name)
+```
+
+This extra file table handles archives that contain more than one `.vpk` without overloading the item row.
+
+## Filesystem Layout
+
+Use a cache separate from Steam Workshop:
+
+```text
+${LEFT4ME_ROOT}/
+  global_overlay_cache/
+    l4d2center-maps/
+      archives/
+      vpks/
+    cedapug-maps/
+      archives/
+      vpks/
+  overlays/
+    {overlay_id}/
+      left4dead2/addons/
+        *.vpk -> absolute symlink to global_overlay_cache/.../vpks/*.vpk
+```
+
+Cache file writes are atomic: download to `*.partial`, extract to a temporary directory, verify, then `os.replace()` final VPK files.
+
+Symlink targets are absolute, matching the existing Workshop overlay design.
+
+## Source Parsing
+
+### L4D2Center
+
+Fetch `https://l4d2center.com/maps/servers/index.csv` with a normal HTTP timeout.
+
+The CSV is semicolon-delimited and contains:
+
+```text
+Name;Size;md5;Download link
+```
+
+Each item produces:
+
+- `item_key = Name`
+- `expected_vpk_name = Name`
+- `expected_size = Size`
+- `expected_md5 = md5`
+- `download_url = Download link`
+
+Downloads are `.7z` archives. Extraction uses a Python 7z implementation such as `py7zr` so tests do not depend on a system `7z` binary. After extraction, the expected VPK file must exist and match both size and md5. A mismatch fails that item and leaves the prior cached file in place.
+
+### CEDAPUG
+
+Fetch `https://cedapug.com/custom` and parse the embedded `renderCustomMapDownloads([...])` data.
+
+Only direct download links are managed in v1:
+
+- Relative links like `/maps/FatalFreight.zip` are converted to absolute `https://cedapug.com/maps/FatalFreight.zip`.
+- External `http` links are logged and skipped in v1.
+- Entries without a download link are built-in campaigns and skipped.
+
+Downloads are `.zip` archives extracted with Python's standard `zipfile`. Every `.vpk` in the archive becomes a managed output file for that item. If no `.vpk` is present, the item fails and the prior cached files remain in place.
+
+Because CEDAPUG does not publish checksums in the observed page, refresh detects changes using `ETag`, `Last-Modified`, `Content-Length`, and local extracted file metadata when available. A manual refresh can force revalidation by clearing item metadata in a later maintenance path; no force-refresh UI is included in this design.
+
+## Refresh Job
+
+`refresh_global_overlays` is a global worker operation.
+
+Behavior:
+
+1. Ensure both managed global overlays and source rows exist.
+2. Fetch both manifests.
+3. Upsert manifest items.
+4. Mark items absent from the manifest as no longer desired by deleting their item rows; cascading deletes remove their file rows.
+5. Download and extract new or changed items.
+6. Keep prior cache files when an item download or verification fails, but record `last_error`.
+7. Rebuild symlinks for changed sources directly through the same builder interface used by `build_overlay`.
+8. Emit clear job logs: manifest counts, downloads, skips, removals, verification failures, and build summaries.
+
+`refresh_global_overlays` does not enqueue child `build_overlay` jobs. Direct builder invocation keeps the overlay in sync before the refresh job releases its global mutex, so a server job cannot start against updated cache metadata but stale overlay symlinks.
+
+Coalescing:
+
+- If a `refresh_global_overlays` job is queued or running, CLI/admin requests return the existing job instead of inserting a duplicate.
+
+## Builder Reconciliation
+
+`GlobalMapOverlayBuilder` reads desired file rows for the overlay's source and reconciles only symlinks it manages.
+
+Managed symlink rule:
+
+- A symlink in `left4dead2/addons/` is managed if its resolved target is under `${LEFT4ME_ROOT}/global_overlay_cache/{source_key}/vpks/`.
+- Managed symlinks absent from desired files are removed.
+- Desired files missing from cache are skipped and logged as errors.
+- Non-symlink files and symlinks outside the source cache are left untouched and logged as foreign entries.
+
+This mirrors `WorkshopBuilder` behavior and keeps manual files safe.
+
+## Scheduler Rules
+
+`refresh_global_overlays` joins the existing global mutex group.
+
+It must not run concurrently with:
+
+- `install`
+- `refresh_workshop_items`
+- any `build_overlay`
+- any server job (`initialize`, `start`, `stop`, `delete`)
+
+No server or overlay job may start while `refresh_global_overlays` is running.
+
+This conservative rule is acceptable because daily map refreshes are rare and large downloads should not race runtime changes.
+
+## CLI And Systemd Timer
+
+Add Flask CLI command:
+
+```text
+flask refresh-global-overlays
+```
+
+The command:
+
+- Loads app config and DB.
+- Ensures global overlays exist.
+- Enqueues or returns the existing `refresh_global_overlays` job.
+- Prints the job id.
+- Does not run downloads itself.
+
+Add deployment units:
+
+```text
+left4me-refresh-global-overlays.service
+left4me-refresh-global-overlays.timer
+```
+
+Service command:
+
+```text
+/opt/left4me/.venv/bin/flask --app l4d2web.app:create_app refresh-global-overlays
+```
+
+Timer policy:
+
+```text
+OnCalendar=daily
+Persistent=true
+```
+
+The service runs as the `left4me` user with `/etc/left4me/host.env` and `/etc/left4me/web.env`, matching `left4me-web.service`.
+
+## Permissions And UI
+
+Overlay list behavior:
+
+- Admins see all overlays, including managed global map overlays.
+- Non-admin users see system overlays and their own private workshop overlays.
+- Managed global overlays appear in blueprint overlay selection for every user.
+
+Creation behavior:
+
+- Non-admin users can create only user-creatable types, currently `workshop`.
+- Admins can create normal admin-creatable types, currently `external` and `workshop`.
+- No user-facing create form offers `l4d2center_maps` or `cedapug_maps`.
+- Auto-seeding is the only creation path for managed global map overlay types.
+
+Admin controls:
+
+- Add a manual "Refresh global overlays" action in the admin area.
+- The action enqueues the same coalesced `refresh_global_overlays` job as the timer.
+- Managed overlay detail pages show source type, source URL, last refresh time, last error, item count, and latest related jobs.
+
+## Error Handling
+
+- Manifest fetch failure fails the job if no source can be processed. If one source succeeds and one fails, the job should still finish failed with partial-success logs and preserve prior content for the failed source.
+- Per-item download failures do not abort sibling items.
+- Verification failures keep prior cached files and record `last_error` on the item.
+- Extraction rejects path traversal entries and ignores non-VPK files.
+- Unsupported CEDAPUG external links are skipped with a warning.
+- Initialize-time checks fail if desired global map files are missing from cache, naming the overlay and missing VPK names.
+
+## Tests
+
+Test coverage should include:
+
+- Auto-seeding creates exactly one source overlay per source and repairs missing source rows.
+- `jobs.user_id` nullable behavior, outer joins, and `system` display.
+- Non-admins cannot access system jobs directly.
+- CLI coalesces queued/running `refresh_global_overlays` jobs.
+- Scheduler truth table for the new global operation.
+- L4D2Center CSV parser with semicolon-delimited fixture data.
+- CEDAPUG embedded JavaScript parser with fixture HTML.
+- L4D2Center download/extract verifies VPK size and md5.
+- CEDAPUG download/extract records every VPK in a zip archive.
+- Reconcile removes obsolete managed symlinks and leaves foreign files alone.
+- Overlay create UI rejects managed singleton types.
+- Blueprint overlay selection includes managed global overlays for all users.
+- Deployment tests cover the service and timer artifacts.
+
+## Out Of Scope
+
+- User-created global map source overlays.
+- Arbitrary configurable HTTP manifest sources.
+- Force-refresh UI for CEDAPUG items.
+- Cache garbage collection for unreferenced archive files.
+- Client-side map download UX.
+- Steam Workshop links discovered on the CEDAPUG page; those are skipped rather than imported into workshop overlays.
+- Host-library awareness of managed overlay types.
+
+## Implementation Boundaries
+
+- `l4d2host` remains unchanged.
+- The web app continues to call host operations only through `l4d2ctl`.
+- Existing blueprint semantics remain unchanged: overlays are live-linked, ordered, and first overlay has highest precedence.
+- Existing workshop overlay behavior remains unchanged except scheduler interactions with the new global operation.
--- a/l4d2web/alembic/versions/0003_global_map_overlays.py
+++ b/l4d2web/alembic/versions/0003_global_map_overlays.py
@ -0,0 +1,105 @@
+"""global map overlays
+
+Revision ID: 0003_global_map_overlays
+Revises: 0002_workshop_overlays
+Create Date: 2026-05-07
+"""
+from typing import Sequence, Union
+
+from alembic import op
+import sqlalchemy as sa
+
+
+revision: str = "0003_global_map_overlays"
+down_revision: Union[str, Sequence[str], None] = "0002_workshop_overlays"
+branch_labels: Union[str, Sequence[str], None] = None
+depends_on: Union[str, Sequence[str], None] = None
+
+
+def upgrade() -> None:
+    with op.batch_alter_table("jobs") as batch_op:
+        batch_op.alter_column("user_id", existing_type=sa.Integer(), nullable=True)
+
+    op.create_table(
+        "global_overlay_sources",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "overlay_id",
+            sa.Integer(),
+            sa.ForeignKey("overlays.id", ondelete="CASCADE"),
+            nullable=False,
+            unique=True,
+        ),
+        sa.Column("source_key", sa.String(length=64), nullable=False, unique=True),
+        sa.Column("source_type", sa.String(length=32), nullable=False),
+        sa.Column("source_url", sa.Text(), nullable=False),
+        sa.Column("last_manifest_hash", sa.String(length=64), nullable=False, server_default=""),
+        sa.Column("last_refreshed_at", sa.DateTime(), nullable=True),
+        sa.Column("last_error", sa.Text(), nullable=False, server_default=""),
+        sa.Column("created_at", sa.DateTime(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(), nullable=False),
+    )
+    op.create_index("ix_global_overlay_sources_type", "global_overlay_sources", ["source_type"])
+
+    op.create_table(
+        "global_overlay_items",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "source_id",
+            sa.Integer(),
+            sa.ForeignKey("global_overlay_sources.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("item_key", sa.String(length=255), nullable=False),
+        sa.Column("display_name", sa.String(length=255), nullable=False, server_default=""),
+        sa.Column("download_url", sa.Text(), nullable=False),
+        sa.Column("expected_vpk_name", sa.String(length=255), nullable=False, server_default=""),
+        sa.Column("expected_size", sa.BigInteger(), nullable=True),
+        sa.Column("expected_md5", sa.String(length=32), nullable=False, server_default=""),
+        sa.Column("etag", sa.String(length=255), nullable=False, server_default=""),
+        sa.Column("last_modified", sa.String(length=255), nullable=False, server_default=""),
+        sa.Column("content_length", sa.BigInteger(), nullable=True),
+        sa.Column("last_downloaded_at", sa.DateTime(), nullable=True),
+        sa.Column("last_error", sa.Text(), nullable=False, server_default=""),
+        sa.Column("created_at", sa.DateTime(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(), nullable=False),
+        sa.UniqueConstraint("source_id", "item_key", name="uq_global_overlay_item_source_key"),
+    )
+    op.create_index("ix_global_overlay_items_source", "global_overlay_items", ["source_id"])
+
+    op.create_table(
+        "global_overlay_item_files",
+        sa.Column("id", sa.Integer(), primary_key=True),
+        sa.Column(
+            "item_id",
+            sa.Integer(),
+            sa.ForeignKey("global_overlay_items.id", ondelete="CASCADE"),
+            nullable=False,
+        ),
+        sa.Column("vpk_name", sa.String(length=255), nullable=False),
+        sa.Column("cache_path", sa.Text(), nullable=False),
+        sa.Column("size", sa.BigInteger(), nullable=False),
+        sa.Column("md5", sa.String(length=32), nullable=False, server_default=""),
+        sa.Column("created_at", sa.DateTime(), nullable=False),
+        sa.Column("updated_at", sa.DateTime(), nullable=False),
+        sa.UniqueConstraint("item_id", "vpk_name", name="uq_global_overlay_item_file_name"),
+    )
+    op.create_index("ix_global_overlay_item_files_item", "global_overlay_item_files", ["item_id"])
+
+
+def downgrade() -> None:
+    op.drop_index("ix_global_overlay_item_files_item", table_name="global_overlay_item_files")
+    op.drop_table("global_overlay_item_files")
+    op.drop_index("ix_global_overlay_items_source", table_name="global_overlay_items")
+    op.drop_table("global_overlay_items")
+    op.drop_index("ix_global_overlay_sources_type", table_name="global_overlay_sources")
+    op.drop_table("global_overlay_sources")
+
+    op.execute(
+        "DELETE FROM job_logs WHERE job_id IN "
+        "(SELECT id FROM jobs WHERE user_id IS NULL)"
+    )
+    op.execute("DELETE FROM jobs WHERE user_id IS NULL")
+
+    with op.batch_alter_table("jobs") as batch_op:
+        batch_op.alter_column("user_id", existing_type=sa.Integer(), nullable=False)
--- a/l4d2web/cli.py
+++ b/l4d2web/cli.py
@ -41,6 +41,20 @@ def create_user(username: str, admin: bool) -> None:
    click.echo(f"created user {username}")


+@click.command("refresh-global-overlays")
+def refresh_global_overlays_command() -> None:
+    from l4d2web.services.global_overlays import (
+        ensure_global_overlays,
+        enqueue_refresh_global_overlays,
+    )
+
+    with session_scope() as db:
+        ensure_global_overlays(db)
+        job = enqueue_refresh_global_overlays(db, user_id=None)
+        click.echo(f"queued refresh_global_overlays job #{job.id}")
+
+
 def register_cli(app) -> None:
    app.cli.add_command(promote_admin)
    app.cli.add_command(create_user)
+    app.cli.add_command(refresh_global_overlays_command)
--- a/l4d2web/models.py
+++ b/l4d2web/models.py
@ -63,6 +63,69 @@ class Overlay(Base):
    updated_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)


+class GlobalOverlaySource(Base):
+    __tablename__ = "global_overlay_sources"
+    __table_args__ = (Index("ix_global_overlay_sources_type", "source_type"),)
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    overlay_id: Mapped[int] = mapped_column(
+        ForeignKey("overlays.id", ondelete="CASCADE"), unique=True, nullable=False
+    )
+    source_key: Mapped[str] = mapped_column(String(64), unique=True, nullable=False)
+    source_type: Mapped[str] = mapped_column(String(32), nullable=False)
+    source_url: Mapped[str] = mapped_column(Text, nullable=False)
+    last_manifest_hash: Mapped[str] = mapped_column(String(64), default="", nullable=False)
+    last_refreshed_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    last_error: Mapped[str] = mapped_column(Text, default="", nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)
+
+
+class GlobalOverlayItem(Base):
+    __tablename__ = "global_overlay_items"
+    __table_args__ = (
+        UniqueConstraint("source_id", "item_key", name="uq_global_overlay_item_source_key"),
+        Index("ix_global_overlay_items_source", "source_id"),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    source_id: Mapped[int] = mapped_column(
+        ForeignKey("global_overlay_sources.id", ondelete="CASCADE"), nullable=False
+    )
+    item_key: Mapped[str] = mapped_column(String(255), nullable=False)
+    display_name: Mapped[str] = mapped_column(String(255), default="", nullable=False)
+    download_url: Mapped[str] = mapped_column(Text, nullable=False)
+    expected_vpk_name: Mapped[str] = mapped_column(String(255), default="", nullable=False)
+    expected_size: Mapped[int | None] = mapped_column(BigInteger, nullable=True)
+    expected_md5: Mapped[str] = mapped_column(String(32), default="", nullable=False)
+    etag: Mapped[str] = mapped_column(String(255), default="", nullable=False)
+    last_modified: Mapped[str] = mapped_column(String(255), default="", nullable=False)
+    content_length: Mapped[int | None] = mapped_column(BigInteger, nullable=True)
+    last_downloaded_at: Mapped[datetime | None] = mapped_column(DateTime, nullable=True)
+    last_error: Mapped[str] = mapped_column(Text, default="", nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)
+
+
+class GlobalOverlayItemFile(Base):
+    __tablename__ = "global_overlay_item_files"
+    __table_args__ = (
+        UniqueConstraint("item_id", "vpk_name", name="uq_global_overlay_item_file_name"),
+        Index("ix_global_overlay_item_files_item", "item_id"),
+    )
+
+    id: Mapped[int] = mapped_column(Integer, primary_key=True)
+    item_id: Mapped[int] = mapped_column(
+        ForeignKey("global_overlay_items.id", ondelete="CASCADE"), nullable=False
+    )
+    vpk_name: Mapped[str] = mapped_column(String(255), nullable=False)
+    cache_path: Mapped[str] = mapped_column(Text, nullable=False)
+    size: Mapped[int] = mapped_column(BigInteger, nullable=False)
+    md5: Mapped[str] = mapped_column(String(32), default="", nullable=False)
+    created_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)
+    updated_at: Mapped[datetime] = mapped_column(DateTime, default=now_utc, nullable=False)
+
+
 class WorkshopItem(Base):
    __tablename__ = "workshop_items"

@ -139,7 +202,7 @@ class Job(Base):
    __tablename__ = "jobs"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
-    user_id: Mapped[int] = mapped_column(ForeignKey("users.id"), nullable=False)
+    user_id: Mapped[int | None] = mapped_column(ForeignKey("users.id"), nullable=True)
    server_id: Mapped[int | None] = mapped_column(ForeignKey("servers.id"), nullable=True)
    overlay_id: Mapped[int | None] = mapped_column(ForeignKey("overlays.id"), nullable=True)
    operation: Mapped[str] = mapped_column(String(32), nullable=False)
--- a/l4d2web/pyproject.toml
+++ b/l4d2web/pyproject.toml
@ -15,6 +15,7 @@ dependencies = [
  "PyYAML>=6.0",
  "gunicorn>=22.0",
  "requests>=2.31",
+  "py7zr>=0.21",
 ]

 [tool.setuptools]
--- a/l4d2web/routes/blueprint_routes.py
+++ b/l4d2web/routes/blueprint_routes.py
@ -6,7 +6,7 @@ from sqlalchemy import delete, func, select
 from l4d2web.auth import current_user, require_login
 from l4d2web.db import session_scope
 from l4d2web.models import Blueprint as BlueprintModel
-from l4d2web.models import BlueprintOverlay, Server
+from l4d2web.models import BlueprintOverlay, Overlay, Server


 bp = Blueprint("blueprint", __name__)
@ -37,6 +37,19 @@ def replace_blueprint_overlays(db, blueprint_id: int, overlay_ids: list[int]) ->
        db.add(BlueprintOverlay(blueprint_id=blueprint_id, overlay_id=overlay_id, position=position))


+def overlay_ids_authorized(db, overlay_ids: list[int], user_id: int) -> bool:
+    unique_ids = set(overlay_ids)
+    if not unique_ids:
+        return True
+    allowed_count = db.scalar(
+        select(func.count(Overlay.id)).where(
+            Overlay.id.in_(unique_ids),
+            Overlay.user_id.is_(None) | (Overlay.user_id == user_id),
+        )
+    )
+    return allowed_count == len(unique_ids)
+
+
@bp.post("/blueprints")
@require_login
 def create_blueprint() -> Response:
@ -61,6 +74,8 @@ def create_blueprint() -> Response:
        return Response("name is required", status=400)

    with session_scope() as db:
+        if not overlay_ids_authorized(db, overlay_ids, user.id):
+            return Response("overlay not authorized", status=403)
        blueprint = BlueprintModel(user_id=user.id, name=name, arguments=json.dumps(arguments), config=json.dumps(config))
        db.add(blueprint)
        db.flush()
@ -87,11 +102,14 @@ def update_blueprint_form(blueprint_id: int) -> Response:
        )
        if blueprint is None:
            return Response(status=404)
+        overlay_ids = ordered_overlay_ids_from_form()
+        if not overlay_ids_authorized(db, overlay_ids, user.id):
+            return Response("overlay not authorized", status=403)

        blueprint.name = name
        blueprint.arguments = json.dumps(split_textarea_lines(request.form.get("arguments", "")))
        blueprint.config = json.dumps(split_textarea_lines(request.form.get("config", "")))
-        replace_blueprint_overlays(db, blueprint.id, ordered_overlay_ids_from_form())
+        replace_blueprint_overlays(db, blueprint.id, overlay_ids)

    return redirect(f"/blueprints/{blueprint_id}")

--- a/l4d2web/routes/job_routes.py
+++ b/l4d2web/routes/job_routes.py
@ -22,7 +22,11 @@ def format_sse_event(seq: int, event: str, data: str) -> str:


 def can_access_job(job: Job, user: User) -> bool:
-    return user.admin or job.user_id == user.id
+    if user.admin:
+        return True
+    if job.user_id is None:
+        return False
+    return job.user_id == user.id


@bp.get("/jobs/<int:job_id>")
@ -34,7 +38,7 @@ def job_detail(job_id: int) -> str | Response:
    with session_scope() as db:
        row = db.execute(
            select(Job, User, Server)
-            .join(User, User.id == Job.user_id)
+            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .where(Job.id == job_id)
        ).first()
--- a/l4d2web/routes/overlay_routes.py
+++ b/l4d2web/routes/overlay_routes.py
@ -8,6 +8,7 @@ from l4d2host.paths import get_left4me_root
 from l4d2web.auth import current_user, require_login
 from l4d2web.db import session_scope
 from l4d2web.models import BlueprintOverlay, Overlay
+from l4d2web.services.global_overlays import MANAGED_GLOBAL_OVERLAY_TYPES, is_creatable_overlay_type
 from l4d2web.services.overlay_creation import (
    create_overlay_directory,
    generate_overlay_path,
@ -17,9 +18,6 @@ from l4d2web.services.overlay_creation import (
 bp = Blueprint("overlay", __name__)


-VALID_TYPES = {"external", "workshop"}
-
-
 def _is_managed_path(overlay: Overlay) -> bool:
    return overlay.path == str(overlay.id)

@ -27,6 +25,8 @@ def _is_managed_path(overlay: Overlay) -> bool:
 def _can_edit_overlay(overlay: Overlay, user) -> bool:
    if user is None:
        return False
+    if overlay.type in MANAGED_GLOBAL_OVERLAY_TYPES:
+        return False
    if user.admin:
        return True
    if overlay.type == "external":
@ -57,7 +57,7 @@ def create_overlay() -> Response:
    overlay_type = request.form.get("type", "external").strip().lower()
    if not name:
        return Response("missing fields", status=400)
-    if overlay_type not in VALID_TYPES:
+    if not is_creatable_overlay_type(overlay_type, admin=user.admin):
        return Response(f"unknown overlay type: {overlay_type}", status=400)

    if overlay_type == "external":
--- a/l4d2web/routes/page_routes.py
+++ b/l4d2web/routes/page_routes.py
@ -8,6 +8,7 @@ from l4d2web.db import session_scope
 from l4d2web.models import Blueprint as BlueprintModel
 from l4d2web.models import (
    BlueprintOverlay,
+    GlobalOverlaySource,
    Job,
    Overlay,
    OverlayWorkshopItem,
@ -42,6 +43,22 @@ def enqueue_runtime_install() -> Response:
    return redirect("/admin/jobs")


+@bp.post("/admin/global-overlays/refresh")
+@require_admin
+def enqueue_global_overlay_refresh() -> Response:
+    user = current_user()
+    assert user is not None
+    from l4d2web.services.global_overlays import (
+        ensure_global_overlays,
+        enqueue_refresh_global_overlays,
+    )
+
+    with session_scope() as db:
+        ensure_global_overlays(db)
+        enqueue_refresh_global_overlays(db, user_id=user.id)
+    return redirect("/admin/jobs")
+
+
@bp.get("/admin/users")
@require_admin
 def admin_users() -> str:
@ -56,7 +73,7 @@ def admin_jobs() -> str:
    with session_scope() as db:
        rows = db.execute(
            select(Job, User, Server)
-            .join(User, User.id == Job.user_id)
+            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .order_by(Job.created_at.desc())
        ).all()
@ -110,7 +127,7 @@ def server_detail(server_id: int):
        blueprint = db.scalar(select(BlueprintModel).where(BlueprintModel.id == server.blueprint_id))
        recent_job_rows = db.execute(
            select(Job, User, Server)
-            .join(User, User.id == Job.user_id)
+            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .where(Job.server_id == server.id)
            .order_by(Job.created_at.desc())
@ -137,7 +154,7 @@ def server_jobs_page(server_id: int):
            return Response(status=404)
        rows = db.execute(
            select(Job, User, Server)
-            .join(User, User.id == Job.user_id)
+            .outerjoin(User, User.id == Job.user_id)
            .outerjoin(Server, Server.id == Job.server_id)
            .where(Job.server_id == server.id)
            .order_by(Job.created_at.desc())
@ -155,7 +172,7 @@ def overlays() -> str:
        query = select(Overlay).order_by(Overlay.name)
        if not user.admin:
            query = query.where(
-                (Overlay.type == "external") | (Overlay.user_id == user.id)
+                Overlay.user_id.is_(None) | (Overlay.user_id == user.id)
            )
        overlays = db.scalars(query).all()
    return render_template("overlays.html", overlays=overlays)
@ -170,16 +187,20 @@ def overlay_detail(overlay_id: int):
        overlay = db.scalar(select(Overlay).where(Overlay.id == overlay_id))
        if overlay is None:
            return Response(status=404)
-        # Visibility: externals are visible to all; workshop overlays are
-        # visible to the owner and admins.
-        if overlay.type == "workshop" and not user.admin and overlay.user_id != user.id:
+        if not user.admin and overlay.user_id is not None and overlay.user_id != user.id:
            return Response(status=403)
-        using_blueprints = db.scalars(
+        global_source = db.scalar(
+            select(GlobalOverlaySource).where(GlobalOverlaySource.overlay_id == overlay.id)
+        )
+        using_blueprints_query = (
            select(BlueprintModel)
            .join(BlueprintOverlay, BlueprintOverlay.blueprint_id == BlueprintModel.id)
            .where(BlueprintOverlay.overlay_id == overlay.id)
            .order_by(BlueprintModel.name)
-        ).all()
+        )
+        if not user.admin:
+            using_blueprints_query = using_blueprints_query.where(BlueprintModel.user_id == user.id)
+        using_blueprints = db.scalars(using_blueprints_query).all()
        workshop_items = []
        if overlay.type == "workshop":
            workshop_items = db.scalars(
@ -200,6 +221,7 @@ def overlay_detail(overlay_id: int):
    return render_template(
        "overlay_detail.html",
        overlay=overlay,
+        global_source=global_source,
        using_blueprints=using_blueprints,
        workshop_items=workshop_items,
        latest_build_job=latest_build_job,
@ -241,7 +263,11 @@ def blueprint_page(blueprint_id: int):
            select(BlueprintOverlay.overlay_id, BlueprintOverlay.position)
            .where(BlueprintOverlay.blueprint_id == blueprint.id)
        ).all()
-        all_overlays = db.scalars(select(Overlay).order_by(Overlay.name)).all()
+        all_overlays = db.scalars(
+            select(Overlay)
+            .where(Overlay.user_id.is_(None) | (Overlay.user_id == user.id))
+            .order_by(Overlay.name)
+        ).all()

    overlay_positions = {overlay_id: position + 1 for overlay_id, position in position_rows}
    return render_template(
--- a/l4d2web/services/global_map_cache.py
+++ b/l4d2web/services/global_map_cache.py
@ -0,0 +1,106 @@
+from __future__ import annotations
+
+import hashlib
+import os
+import shutil
+from pathlib import Path
+import tempfile
+from zipfile import ZipFile
+
+import py7zr
+import requests
+
+from l4d2host.paths import get_left4me_root
+
+
+REQUEST_TIMEOUT_SECONDS = 30
+DOWNLOAD_CHUNK_BYTES = 1_048_576
+
+
+def global_overlay_cache_root() -> Path:
+    return get_left4me_root() / "global_overlay_cache"
+
+
+def source_cache_root(source_key: str) -> Path:
+    if "/" in source_key or ".." in source_key or not source_key:
+        raise ValueError(f"invalid source_key: {source_key!r}")
+    return global_overlay_cache_root() / source_key
+
+
+def archive_dir(source_key: str) -> Path:
+    return source_cache_root(source_key) / "archives"
+
+
+def vpk_dir(source_key: str) -> Path:
+    return source_cache_root(source_key) / "vpks"
+
+
+def download_archive(url: str, target: Path, *, should_cancel=None) -> tuple[str, str, int | None]:
+    target.parent.mkdir(parents=True, exist_ok=True)
+    partial = target.with_suffix(target.suffix + ".partial")
+    response = requests.get(url, stream=True, timeout=REQUEST_TIMEOUT_SECONDS)
+    response.raise_for_status()
+    etag = response.headers.get("ETag", "")
+    last_modified = response.headers.get("Last-Modified", "")
+    content_length_raw = response.headers.get("Content-Length")
+    content_length = int(content_length_raw) if content_length_raw and content_length_raw.isdigit() else None
+    try:
+        with open(partial, "wb") as f:
+            for chunk in response.iter_content(chunk_size=DOWNLOAD_CHUNK_BYTES):
+                if should_cancel is not None and should_cancel():
+                    raise InterruptedError("download cancelled")
+                if chunk:
+                    f.write(chunk)
+        os.replace(partial, target)
+    except BaseException:
+        partial.unlink(missing_ok=True)
+        raise
+    return etag, last_modified, content_length
+
+
+def safe_extract_zip_vpks(archive_path: Path, output_dir: Path) -> list[Path]:
+    output_dir.mkdir(parents=True, exist_ok=True)
+    extracted: list[Path] = []
+    with ZipFile(archive_path) as zf:
+        for member in zf.infolist():
+            name = Path(member.filename)
+            if name.is_absolute() or any(part in {"", ".", ".."} for part in name.parts):
+                raise ValueError(f"unsafe archive member: {member.filename}")
+            if name.suffix.lower() != ".vpk":
+                continue
+            target = output_dir / name.name
+            with zf.open(member) as src, open(target, "wb") as dst:
+                shutil.copyfileobj(src, dst)
+            extracted.append(target)
+    if not extracted:
+        raise ValueError(f"archive {archive_path} did not contain any .vpk files")
+    return sorted(extracted)
+
+
+def safe_extract_7z_vpks(archive_path: Path, output_dir: Path) -> list[Path]:
+    output_dir.mkdir(parents=True, exist_ok=True)
+    with tempfile.TemporaryDirectory(prefix="left4me-7z-") as raw_tmp:
+        raw_dir = Path(raw_tmp)
+        with py7zr.SevenZipFile(archive_path, mode="r") as archive:
+            names = archive.getnames()
+            for name in names:
+                p = Path(name)
+                if p.is_absolute() or any(part in {"", ".", ".."} for part in p.parts):
+                    raise ValueError(f"unsafe archive member: {name}")
+            archive.extractall(path=raw_dir)
+        extracted: list[Path] = []
+        for candidate in raw_dir.rglob("*.vpk"):
+            target = output_dir / candidate.name
+            shutil.move(str(candidate), str(target))
+            extracted.append(target)
+    if not extracted:
+        raise ValueError(f"archive {archive_path} did not contain any .vpk files")
+    return sorted(extracted)
+
+
+def extracted_vpk_md5(path: Path) -> str:
+    digest = hashlib.md5()
+    with open(path, "rb") as f:
+        for chunk in iter(lambda: f.read(1024 * 1024), b""):
+            digest.update(chunk)
+    return digest.hexdigest()
--- a/l4d2web/services/global_map_sources.py
+++ b/l4d2web/services/global_map_sources.py
@ -0,0 +1,104 @@
+from __future__ import annotations
+
+import csv
+from dataclasses import dataclass
+import hashlib
+import html as html_lib
+import io
+import json
+from urllib.parse import urljoin, urlparse
+import re
+
+import requests
+
+
+REQUEST_TIMEOUT_SECONDS = 30
+L4D2CENTER_CSV_URL = "https://l4d2center.com/maps/servers/index.csv"
+CEDAPUG_CUSTOM_URL = "https://cedapug.com/custom"
+
+
+@dataclass(frozen=True, slots=True)
+class GlobalMapManifestItem:
+    item_key: str
+    display_name: str
+    download_url: str
+    expected_vpk_name: str = ""
+    expected_size: int | None = None
+    expected_md5: str = ""
+
+
+def fetch_l4d2center_manifest() -> tuple[str, list[GlobalMapManifestItem]]:
+    response = requests.get(L4D2CENTER_CSV_URL, timeout=REQUEST_TIMEOUT_SECONDS)
+    response.raise_for_status()
+    text = response.text
+    return _sha256(text), parse_l4d2center_csv(text)
+
+
+def fetch_cedapug_manifest() -> tuple[str, list[GlobalMapManifestItem]]:
+    response = requests.get(CEDAPUG_CUSTOM_URL, timeout=REQUEST_TIMEOUT_SECONDS)
+    response.raise_for_status()
+    text = response.text
+    return _sha256(text), parse_cedapug_custom_html(text)
+
+
+def parse_l4d2center_csv(raw: str) -> list[GlobalMapManifestItem]:
+    reader = csv.DictReader(io.StringIO(raw), delimiter=";")
+    expected = ["Name", "Size", "md5", "Download link"]
+    if reader.fieldnames != expected:
+        raise ValueError("expected L4D2Center CSV header: Name;Size;md5;Download link")
+    items: list[GlobalMapManifestItem] = []
+    for row in reader:
+        name = (row.get("Name") or "").strip()
+        size_raw = (row.get("Size") or "").strip()
+        md5 = (row.get("md5") or "").strip().lower()
+        url = (row.get("Download link") or "").strip()
+        if not name or not url:
+            continue
+        items.append(
+            GlobalMapManifestItem(
+                item_key=name,
+                display_name=name,
+                download_url=url,
+                expected_vpk_name=name,
+                expected_size=int(size_raw) if size_raw else None,
+                expected_md5=md5,
+            )
+        )
+    return items
+
+
+def parse_cedapug_custom_html(raw: str) -> list[GlobalMapManifestItem]:
+    match = re.search(r"renderCustomMapDownloads\((\[.*?\])\)</script>", raw, re.DOTALL)
+    if match is None:
+        raise ValueError("CEDAPUG page did not contain renderCustomMapDownloads data")
+    rows = json.loads(match.group(1))
+    items: list[GlobalMapManifestItem] = []
+    for row in rows:
+        if len(row) < 3:
+            continue
+        label = str(row[1])
+        link = str(row[2])
+        if link.startswith("http"):
+            continue
+        if not link:
+            continue
+        url = urljoin(CEDAPUG_CUSTOM_URL, link)
+        parsed = urlparse(url)
+        basename = parsed.path.rsplit("/", 1)[-1]
+        items.append(
+            GlobalMapManifestItem(
+                item_key=basename,
+                display_name=_strip_html(label),
+                download_url=url,
+            )
+        )
+    return items
+
+
+def _strip_html(raw: str) -> str:
+    no_tags = re.sub(r"<[^>]+>", "", raw)
+    return html_lib.unescape(no_tags).strip()
+
+
+def _sha256(raw: str) -> str:
+    return hashlib.sha256(raw.encode("utf-8")).hexdigest()
--- a/l4d2web/services/global_overlay_refresh.py
+++ b/l4d2web/services/global_overlay_refresh.py
@ -0,0 +1,168 @@
+from __future__ import annotations
+
+import shutil
+from datetime import UTC, datetime
+from pathlib import Path
+import tempfile
+
+from sqlalchemy import select
+
+from l4d2web.db import session_scope
+from l4d2web.models import GlobalOverlayItem, GlobalOverlayItemFile, GlobalOverlaySource, Overlay
+from l4d2web.services.global_map_cache import (
+    archive_dir,
+    download_archive,
+    extracted_vpk_md5,
+    safe_extract_7z_vpks,
+    safe_extract_zip_vpks,
+    vpk_dir,
+)
+from l4d2web.services.global_map_sources import (
+    GlobalMapManifestItem,
+    fetch_cedapug_manifest,
+    fetch_l4d2center_manifest,
+)
+from l4d2web.services.global_overlays import ensure_global_overlays
+
+
+def refresh_global_overlays(*, on_stdout, on_stderr, should_cancel) -> list[str]:
+    with session_scope() as db:
+        ensure_global_overlays(db)
+
+    refreshed: list[str] = []
+    for source_key, fetcher in (
+        ("l4d2center-maps", fetch_l4d2center_manifest),
+        ("cedapug-maps", fetch_cedapug_manifest),
+    ):
+        if should_cancel():
+            on_stderr("global overlay refresh cancelled before manifest fetch")
+            return refreshed
+        manifest_hash, manifest_items = fetcher()
+        on_stdout(f"{source_key}: fetched manifest with {len(manifest_items)} item(s)")
+        overlay = _refresh_source(
+            source_key,
+            manifest_hash,
+            manifest_items,
+            on_stdout=on_stdout,
+            on_stderr=on_stderr,
+            should_cancel=should_cancel,
+        )
+        build_global_overlay(overlay, on_stdout=on_stdout, on_stderr=on_stderr, should_cancel=should_cancel)
+        refreshed.append(source_key)
+    return sorted(refreshed)
+
+
+def _refresh_source(source_key: str, manifest_hash: str, manifest_items: list[GlobalMapManifestItem], *, on_stdout, on_stderr, should_cancel) -> Overlay:
+    now = datetime.now(UTC)
+    desired_keys = {item.item_key for item in manifest_items}
+    with session_scope() as db:
+        source = db.scalar(select(GlobalOverlaySource).where(GlobalOverlaySource.source_key == source_key))
+        if source is None:
+            raise ValueError(f"global overlay source {source_key!r} not found")
+        overlay = db.scalar(select(Overlay).where(Overlay.id == source.overlay_id))
+        if overlay is None:
+            raise ValueError(f"overlay for source {source_key!r} not found")
+        existing_items = {item.item_key: item for item in db.scalars(select(GlobalOverlayItem).where(GlobalOverlayItem.source_id == source.id)).all()}
+        for old_key, old_item in list(existing_items.items()):
+            if old_key not in desired_keys:
+                db.delete(old_item)
+        for manifest_item in manifest_items:
+            item = existing_items.get(manifest_item.item_key)
+            if item is None:
+                item = GlobalOverlayItem(source_id=source.id, item_key=manifest_item.item_key, download_url=manifest_item.download_url)
+                db.add(item)
+                db.flush()
+            item.display_name = manifest_item.display_name
+            item.download_url = manifest_item.download_url
+            item.expected_vpk_name = manifest_item.expected_vpk_name
+            item.expected_size = manifest_item.expected_size
+            item.expected_md5 = manifest_item.expected_md5
+            item.updated_at = now
+        source.last_manifest_hash = manifest_hash
+        source.last_refreshed_at = now
+        source.last_error = ""
+        source.updated_at = now
+        db.expunge(overlay)
+
+    for manifest_item in manifest_items:
+        if should_cancel():
+            on_stderr(f"{source_key}: refresh cancelled during downloads")
+            return overlay
+        _refresh_item(source_key, manifest_item, on_stdout=on_stdout, on_stderr=on_stderr, should_cancel=should_cancel)
+    return overlay
+
+
+def _refresh_item(source_key: str, manifest_item: GlobalMapManifestItem, *, on_stdout, on_stderr, should_cancel) -> None:
+    try:
+        files, etag, last_modified, content_length = download_and_extract_item(source_key, manifest_item, should_cancel=should_cancel)
+    except Exception as exc:
+        with session_scope() as db:
+            source = db.scalar(select(GlobalOverlaySource).where(GlobalOverlaySource.source_key == source_key))
+            if source is not None:
+                item = db.scalar(select(GlobalOverlayItem).where(GlobalOverlayItem.source_id == source.id, GlobalOverlayItem.item_key == manifest_item.item_key))
+                if item is not None:
+                    item.last_error = str(exc)
+        on_stderr(f"{source_key}: {manifest_item.item_key}: {exc}")
+        return
+
+    now = datetime.now(UTC)
+    with session_scope() as db:
+        source = db.scalar(select(GlobalOverlaySource).where(GlobalOverlaySource.source_key == source_key))
+        if source is None:
+            raise ValueError(f"global overlay source {source_key!r} not found")
+        item = db.scalar(select(GlobalOverlayItem).where(GlobalOverlayItem.source_id == source.id, GlobalOverlayItem.item_key == manifest_item.item_key))
+        if item is None:
+            raise ValueError(f"global overlay item {manifest_item.item_key!r} not found")
+        db.query(GlobalOverlayItemFile).filter_by(item_id=item.id).delete()
+        for vpk_name, cache_path, size, md5 in files:
+            db.add(GlobalOverlayItemFile(item_id=item.id, vpk_name=vpk_name, cache_path=cache_path, size=size, md5=md5))
+        item.etag = etag
+        item.last_modified = last_modified
+        item.content_length = content_length
+        item.last_downloaded_at = now
+        item.last_error = ""
+        item.updated_at = now
+    on_stdout(f"{source_key}: refreshed {manifest_item.item_key} ({len(files)} vpk file(s))")
+
+
+def download_and_extract_item(source_key: str, item: GlobalMapManifestItem, *, should_cancel) -> tuple[list[tuple[str, str, int, str]], str, str, int | None]:
+    archives = archive_dir(source_key)
+    vpks = vpk_dir(source_key)
+    archives.mkdir(parents=True, exist_ok=True)
+    vpks.mkdir(parents=True, exist_ok=True)
+    archive_name = item.download_url.rsplit("/", 1)[-1]
+    archive_path = archives / archive_name
+    etag, last_modified, content_length = download_archive(item.download_url, archive_path, should_cancel=should_cancel)
+    with tempfile.TemporaryDirectory(prefix="left4me-global-map-") as tmp:
+        tmp_dir = Path(tmp)
+        if archive_name.lower().endswith(".7z"):
+            extracted = safe_extract_7z_vpks(archive_path, tmp_dir)
+        elif archive_name.lower().endswith(".zip"):
+            extracted = safe_extract_zip_vpks(archive_path, tmp_dir)
+        else:
+            raise ValueError(f"unsupported archive extension for {archive_name}")
+        results: list[tuple[str, str, int, str]] = []
+        for path in extracted:
+            if item.expected_vpk_name and path.name != item.expected_vpk_name:
+                continue
+            size = path.stat().st_size
+            md5 = extracted_vpk_md5(path)
+            if item.expected_size is not None and size != item.expected_size:
+                raise ValueError(f"{path.name} size mismatch: expected {item.expected_size}, got {size}")
+            if item.expected_md5 and md5 != item.expected_md5:
+                raise ValueError(f"{path.name} md5 mismatch: expected {item.expected_md5}, got {md5}")
+            final = vpks / path.name
+            shutil.move(str(path), str(final))
+            results.append((path.name, f"{source_key}/vpks/{path.name}", size, md5))
+        if not results:
+            raise ValueError(f"no expected .vpk files extracted from {archive_name}")
+        return results, etag, last_modified, content_length
+
+
+def build_global_overlay(overlay: Overlay, *, on_stdout, on_stderr, should_cancel) -> None:
+    from l4d2web.services.overlay_builders import BUILDERS
+
+    builder = BUILDERS.get(overlay.type)
+    if builder is None:
+        raise ValueError(f"no builder registered for overlay type {overlay.type!r}")
+    builder.build(overlay, on_stdout=on_stdout, on_stderr=on_stderr, should_cancel=should_cancel)
--- a/l4d2web/services/global_overlays.py
+++ b/l4d2web/services/global_overlays.py
@ -0,0 +1,112 @@
+from __future__ import annotations
+
+from dataclasses import dataclass
+import os
+
+from sqlalchemy import select
+from sqlalchemy.orm import Session
+
+from l4d2host.paths import get_left4me_root
+
+from l4d2web.models import GlobalOverlaySource, Job, Overlay
+from l4d2web.services.overlay_creation import generate_overlay_path
+
+
+@dataclass(frozen=True)
+class ManagedGlobalOverlay:
+    name: str
+    overlay_type: str
+    source_type: str
+    source_url: str
+
+
+GLOBAL_OVERLAYS = (
+    ManagedGlobalOverlay(
+        name="l4d2center-maps",
+        overlay_type="l4d2center_maps",
+        source_type="l4d2center_csv",
+        source_url="https://l4d2center.com/maps/servers/index.csv",
+    ),
+    ManagedGlobalOverlay(
+        name="cedapug-maps",
+        overlay_type="cedapug_maps",
+        source_type="cedapug_custom_page",
+        source_url="https://cedapug.com/custom",
+    ),
+)
+
+MANAGED_GLOBAL_OVERLAY_TYPES = {overlay.overlay_type for overlay in GLOBAL_OVERLAYS}
+USER_CREATABLE_TYPES = {"workshop"}
+ADMIN_CREATABLE_TYPES = {"external", "workshop"}
+
+
+def is_creatable_overlay_type(overlay_type: str, *, admin: bool) -> bool:
+    allowed = ADMIN_CREATABLE_TYPES if admin else USER_CREATABLE_TYPES
+    return overlay_type in allowed
+
+
+def ensure_global_overlays(session: Session) -> set[str]:
+    created_sources: set[str] = set()
+    for managed in GLOBAL_OVERLAYS:
+        overlay = session.scalar(
+            select(Overlay).where(Overlay.name == managed.name, Overlay.user_id.is_(None))
+        )
+        overlay_created = overlay is None
+        if overlay is None:
+            overlay = Overlay(name=managed.name, path="", type=managed.overlay_type, user_id=None)
+            session.add(overlay)
+            session.flush()
+            overlay.path = generate_overlay_path(overlay.id)
+        else:
+            overlay.type = managed.overlay_type
+            overlay.user_id = None
+            if not overlay.path:
+                overlay.path = generate_overlay_path(overlay.id)
+
+        target = get_left4me_root() / "overlays" / overlay.path
+        os.makedirs(target, exist_ok=not overlay_created)
+
+        source = session.scalar(
+            select(GlobalOverlaySource).where(GlobalOverlaySource.source_key == managed.name)
+        )
+        if source is None:
+            source = GlobalOverlaySource(
+                overlay_id=overlay.id,
+                source_key=managed.name,
+                source_type=managed.source_type,
+                source_url=managed.source_url,
+            )
+            session.add(source)
+            created_sources.add(managed.name)
+        else:
+            source.overlay_id = overlay.id
+            source.source_type = managed.source_type
+            source.source_url = managed.source_url
+
+        session.flush()
+
+    return created_sources
+
+
+def enqueue_refresh_global_overlays(session: Session, *, user_id: int | None) -> Job:
+    existing = session.scalar(
+        select(Job)
+        .where(
+            Job.operation == "refresh_global_overlays",
+            Job.state.in_({"queued", "running", "cancelling"}),
+        )
+        .order_by(Job.created_at, Job.id)
+    )
+    if existing is not None:
+        return existing
+
+    job = Job(
+        user_id=user_id,
+        server_id=None,
+        overlay_id=None,
+        operation="refresh_global_overlays",
+        state="queued",
+    )
+    session.add(job)
+    session.flush()
+    return job
--- a/l4d2web/services/job_worker.py
+++ b/l4d2web/services/job_worker.py
@ -27,7 +27,7 @@ TERMINAL_JOB_STATES = {"succeeded", "failed", "cancelled"}
 ACTIVE_JOB_STATES = {"running", "cancelling"}
 SERVER_OPERATIONS = {"initialize", "start", "stop", "delete"}
 OVERLAY_OPERATIONS = {"build_overlay"}
-GLOBAL_OPERATIONS = {"install", "refresh_workshop_items"}
+GLOBAL_OPERATIONS = {"install", "refresh_workshop_items", "refresh_global_overlays"}
 WORKSHOP_REFRESH_DOWNLOAD_WORKERS = 1

 _claim_lock = threading.Lock()
@ -40,6 +40,7 @@ _workers_started = False
 class SchedulerState:
    install_running: bool = False
    refresh_running: bool = False
+    refresh_global_overlays_running: bool = False
    running_servers: set[int] = field(default_factory=set)
    running_overlays: set[int] = field(default_factory=set)
    blocked_servers_by_overlay: set[int] = field(default_factory=set)
@ -62,6 +63,7 @@ def can_start(job, state: SchedulerState) -> bool:
        return (
            not state.install_running
            and not state.refresh_running
+            and not state.refresh_global_overlays_running
            and len(state.running_servers) == 0
            and len(state.running_overlays) == 0
        )
@ -69,17 +71,26 @@ def can_start(job, state: SchedulerState) -> bool:
        return (
            not state.install_running
            and not state.refresh_running
+            and not state.refresh_global_overlays_running
+            and len(state.running_servers) == 0
+            and len(state.running_overlays) == 0
+        )
+    if job.operation == "refresh_global_overlays":
+        return (
+            not state.install_running
+            and not state.refresh_running
+            and not state.refresh_global_overlays_running
            and len(state.running_servers) == 0
            and len(state.running_overlays) == 0
        )
    if job.operation == "build_overlay":
-        if state.install_running or state.refresh_running:
+        if state.install_running or state.refresh_running or state.refresh_global_overlays_running:
            return False
        if job.overlay_id is None:
            return False
        return job.overlay_id not in state.running_overlays
    # Server operations from here on.
-    if state.install_running or state.refresh_running:
+    if state.install_running or state.refresh_running or state.refresh_global_overlays_running:
        return False
    if job.server_id is None:
        return False
@ -98,6 +109,8 @@ def build_scheduler_state(session: Session) -> SchedulerState:
            state.install_running = True
        elif job.operation == "refresh_workshop_items":
            state.refresh_running = True
+        elif job.operation == "refresh_global_overlays":
+            state.refresh_global_overlays_running = True
        elif job.operation == "build_overlay" and job.overlay_id is not None:
            state.running_overlays.add(job.overlay_id)
        elif job.server_id is not None:
@ -247,6 +260,15 @@ def run_job(job_id: int) -> None:
                on_stderr=on_stderr,
                should_cancel=should_cancel,
            )
+        elif operation == "refresh_global_overlays":
+            _run_with_boundaries(
+                "refresh",
+                "global overlays",
+                _run_refresh_global_overlays,
+                on_stdout=on_stdout,
+                on_stderr=on_stderr,
+                should_cancel=should_cancel,
+            )
        elif operation == "build_overlay":
            if overlay_id_for_job is None:
                raise ValueError("build_overlay job has no overlay_id")
@ -368,6 +390,21 @@ def _run_build_overlay(
    )


+def _run_refresh_global_overlays(
+    *,
+    on_stdout: Callable[[str], None],
+    on_stderr: Callable[[str], None],
+    should_cancel: Callable[[], bool],
+) -> list[str]:
+    from l4d2web.services.global_overlay_refresh import refresh_global_overlays
+
+    return refresh_global_overlays(
+        on_stdout=on_stdout,
+        on_stderr=on_stderr,
+        should_cancel=should_cancel,
+    )
+
+
 def _run_refresh_workshop_items(
    *,
    on_stdout: Callable[[str], None],
--- a/l4d2web/services/l4d2_facade.py
+++ b/l4d2web/services/l4d2_facade.py
@ -8,12 +8,16 @@ from l4d2web.db import session_scope
 from l4d2web.models import (
    Blueprint,
    BlueprintOverlay,
+    GlobalOverlayItem,
+    GlobalOverlayItemFile,
+    GlobalOverlaySource,
    Overlay,
    OverlayWorkshopItem,
    Server,
    WorkshopItem,
 )
 from l4d2web.services import host_commands
+from l4d2web.services.global_map_cache import global_overlay_cache_root
 from l4d2web.services.spec_yaml import write_temp_spec
 from l4d2web.services.workshop_paths import cache_path

@ -79,6 +83,7 @@ def initialize_server(server_id: int, on_stdout=None, on_stderr=None, should_can
    # them, but we don't want to mount a partial overlay silently — fail
    # loudly with the missing IDs.
    _check_workshop_overlay_caches(blueprint_id=blueprint.id)
+    _check_global_overlay_caches(blueprint_id=blueprint.id)

    spec_path = write_temp_spec(build_server_spec_payload(server, blueprint, overlay_refs))
    try:
@ -173,6 +178,36 @@ def _check_workshop_overlay_caches(*, blueprint_id: int) -> None:
    )


+def _check_global_overlay_caches(*, blueprint_id: int) -> None:
+    """Raise if any global map overlay attached to this blueprint has manifest
+    items that aren't yet in the global_overlay_cache. Mirrors the workshop
+    cache check — surface partial cache state at initialize time.
+    """
+    with session_scope() as db:
+        rows = db.execute(
+            select(Overlay.name, GlobalOverlayItemFile.vpk_name, GlobalOverlayItemFile.cache_path)
+            .join(BlueprintOverlay, BlueprintOverlay.overlay_id == Overlay.id)
+            .join(GlobalOverlaySource, GlobalOverlaySource.overlay_id == Overlay.id)
+            .join(GlobalOverlayItem, GlobalOverlayItem.source_id == GlobalOverlaySource.id)
+            .join(GlobalOverlayItemFile, GlobalOverlayItemFile.item_id == GlobalOverlayItem.id)
+            .where(BlueprintOverlay.blueprint_id == blueprint_id)
+        ).all()
+
+    missing: dict[str, list[str]] = {}
+    root = global_overlay_cache_root()
+    for overlay_name, vpk_name, cache_path_value in rows:
+        if not (root / cache_path_value).exists():
+            missing.setdefault(overlay_name, []).append(vpk_name)
+
+    if not missing:
+        return
+
+    details = []
+    for overlay_name, names in sorted(missing.items()):
+        details.append(f"overlay {overlay_name!r}: missing {', '.join(sorted(names))}")
+    raise RuntimeError("global overlay content missing — " + "; ".join(details))
+
+
 def start_server(server_id: int, on_stdout=None, on_stderr=None, should_cancel=None) -> None:
    server, _, _ = load_server_blueprint_bundle(server_id)
    host_commands.run_command(
--- a/l4d2web/services/overlay_builders.py
+++ b/l4d2web/services/overlay_builders.py
@ -16,7 +16,8 @@ from sqlalchemy import select
 from l4d2host.paths import get_left4me_root

 from l4d2web.db import session_scope
-from l4d2web.models import Overlay, OverlayWorkshopItem, WorkshopItem
+from l4d2web.models import GlobalOverlayItem, GlobalOverlayItemFile, GlobalOverlaySource, Overlay, OverlayWorkshopItem, WorkshopItem
+from l4d2web.services.global_map_cache import global_overlay_cache_root
 from l4d2web.services.workshop_paths import cache_path, workshop_cache_root


@ -179,6 +180,97 @@ class WorkshopBuilder:
            )


+class GlobalMapOverlayBuilder:
+    """Reconcile symlinks for managed global map overlays."""
+
+    def build(
+        self,
+        overlay: Overlay,
+        *,
+        on_stdout: LogSink,
+        on_stderr: LogSink,
+        should_cancel: CancelCheck,
+    ) -> None:
+        addons_dir = _overlay_root(overlay) / "left4dead2" / "addons"
+        addons_dir.mkdir(parents=True, exist_ok=True)
+
+        with session_scope() as db:
+            source = db.scalar(select(GlobalOverlaySource).where(GlobalOverlaySource.overlay_id == overlay.id))
+            if source is None:
+                raise ValueError(f"global overlay source for overlay {overlay.id} not found")
+            rows = db.execute(
+                select(GlobalOverlayItemFile.vpk_name, GlobalOverlayItemFile.cache_path)
+                .join(GlobalOverlayItem, GlobalOverlayItem.id == GlobalOverlayItemFile.item_id)
+                .where(GlobalOverlayItem.source_id == source.id)
+            ).all()
+            source_key = source.source_key
+
+        cache_root = global_overlay_cache_root().resolve()
+        source_vpk_root = (global_overlay_cache_root() / source_key / "vpks").resolve()
+        desired: dict[str, Path] = {}
+        skipped = 0
+        for vpk_name, cache_path_value in rows:
+            target = (global_overlay_cache_root() / cache_path_value).resolve()
+            if not _is_under(target, source_vpk_root) or not target.exists():
+                on_stderr(f"global overlay {overlay.name!r}: missing cache file for {vpk_name}")
+                skipped += 1
+                continue
+            desired[vpk_name] = target
+
+        existing: dict[str, Path] = {}
+        for entry in os.scandir(addons_dir):
+            if not entry.is_symlink():
+                continue
+            try:
+                resolved = Path(os.readlink(entry.path)).resolve(strict=False)
+            except OSError:
+                continue
+            if _is_under(resolved, source_vpk_root):
+                existing[entry.name] = resolved
+            elif _is_under(resolved, cache_root):
+                on_stderr(f"global overlay {overlay.name!r}: leaving foreign cache symlink {entry.name}")
+
+        created = 0
+        removed = 0
+        unchanged = 0
+        for name, current_target in existing.items():
+            if should_cancel():
+                on_stderr("global overlay build cancelled mid-removal")
+                return
+            desired_target = desired.get(name)
+            if desired_target is None:
+                os.unlink(addons_dir / name)
+                removed += 1
+            elif current_target == desired_target:
+                unchanged += 1
+            else:
+                os.unlink(addons_dir / name)
+
+        current_names = {
+            name for name, current_target in existing.items() if name in desired and current_target == desired[name]
+        }
+        for name, target in desired.items():
+            if should_cancel():
+                on_stderr("global overlay build cancelled mid-creation")
+                return
+            if name in current_names:
+                continue
+            link_path = addons_dir / name
+            if link_path.exists() and not link_path.is_symlink():
+                on_stderr(f"refusing to overwrite non-symlink at {link_path}")
+                continue
+            if link_path.is_symlink():
+                on_stderr(f"refusing to overwrite foreign symlink at {link_path}")
+                continue
+            os.symlink(str(target), str(link_path))
+            created += 1
+
+        on_stdout(
+            f"global overlay {overlay.name!r}: created={created} removed={removed} "
+            f"unchanged={unchanged} skipped(missing)={skipped}"
+        )
+
+
 def _is_under(path: Path, root: Path) -> bool:
    try:
        path.relative_to(root)
@ -190,4 +282,6 @@ def _is_under(path: Path, root: Path) -> bool:
 BUILDERS: dict[str, OverlayBuilder] = {
    "external": ExternalBuilder(),
    "workshop": WorkshopBuilder(),
+    "l4d2center_maps": GlobalMapOverlayBuilder(),
+    "cedapug_maps": GlobalMapOverlayBuilder(),
 }
--- a/l4d2web/templates/_job_table.html
+++ b/l4d2web/templates/_job_table.html
@ -17,7 +17,7 @@
      <td><a href="/jobs/{{ job.id }}">#{{ job.id }}</a></td>
      <td>{{ job.operation }}</td>
      <td>{{ job.state }}</td>
-      {% if show_user %}<td>{{ user.username }}</td>{% endif %}
+      {% if show_user %}<td>{{ user.username if user else "system" }}</td>{% endif %}
      {% if show_server %}<td>{% if server %}<a href="/servers/{{ server.id }}">{{ server.name }}</a>{% else %}-{% endif %}</td>{% endif %}
      <td>{{ job.created_at }}</td>
      <td>{{ job.finished_at or "-" }}</td>
--- a/l4d2web/templates/admin.html
+++ b/l4d2web/templates/admin.html
@ -28,4 +28,13 @@
    <button type="submit">Refresh all workshop items</button>
  </form>
 </section>
+
+<section class="panel">
+  <h2>Global map overlays</h2>
+  <p class="muted">Queue a refresh for managed L4D2Center and CEDAPUG map overlays.</p>
+  <form method="post" action="/admin/global-overlays/refresh">
+    <input type="hidden" name="csrf_token" value="{{ session.get('csrf_token', '') }}">
+    <button type="submit">Refresh global overlays</button>
+  </form>
+</section>
 {% endblock %}
--- a/l4d2web/templates/job_detail.html
+++ b/l4d2web/templates/job_detail.html
@ -19,7 +19,7 @@
    <tbody>
      <tr><th>Operation</th><td>{{ job.operation }}</td></tr>
      <tr><th>State</th><td>{{ job.state }}</td></tr>
-      <tr><th>User</th><td>{{ owner.username }}</td></tr>
+      <tr><th>User</th><td>{{ owner.username if owner else "system" }}</td></tr>
      <tr><th>Server</th><td>{% if server %}<a href="/servers/{{ server.id }}">{{ server.name }}</a>{% else %}-{% endif %}</td></tr>
      <tr><th>Created</th><td>{{ job.created_at }}</td></tr>
      <tr><th>Started</th><td>{{ job.started_at or "-" }}</td></tr>
--- a/l4d2web/templates/overlay_detail.html
+++ b/l4d2web/templates/overlay_detail.html
@ -6,7 +6,7 @@
 <section class="panel">
  <div class="page-heading">
    <h1>Overlay: {{ overlay.name }}</h1>
-    {% set can_edit = g.user.admin or (overlay.type == 'workshop' and overlay.user_id == g.user.id) %}
+    {% set can_edit = overlay.type not in ['l4d2center_maps', 'cedapug_maps'] and (g.user.admin or (overlay.type == 'workshop' and overlay.user_id == g.user.id)) %}
    {% if can_edit %}
    <button type="button" class="danger" data-modal-open="delete-overlay-modal">Delete</button>
    {% endif %}
@ -31,6 +31,20 @@
  </table>
 </section>

+{% if global_source %}
+<section class="panel">
+  <h2>Global source</h2>
+  <table class="definition-table">
+    <tbody>
+      <tr><th>Source key</th><td>{{ global_source.source_key }}</td></tr>
+      <tr><th>Source URL</th><td><a href="{{ global_source.source_url }}">{{ global_source.source_url }}</a></td></tr>
+      <tr><th>Last refreshed</th><td>{{ global_source.last_refreshed_at or "Never" }}</td></tr>
+      <tr><th>Last error</th><td>{{ global_source.last_error or "None" }}</td></tr>
+    </tbody>
+  </table>
+</section>
+{% endif %}
+
 {% if overlay.type == 'workshop' %}
 <section class="panel">
  <div class="page-heading">
--- a/l4d2web/tests/test_blueprints.py
+++ b/l4d2web/tests/test_blueprints.py
@ -79,6 +79,86 @@ def test_user_can_create_private_blueprint(user_client) -> None:
    assert response.status_code == 201


+def _create_other_users_private_overlay() -> int:
+    with session_scope() as session:
+        other = User(username="mallory", password_digest=hash_password("secret"), admin=False)
+        session.add(other)
+        session.flush()
+        overlay = Overlay(
+            name="mallory-private",
+            path="mallory-private",
+            type="workshop",
+            user_id=other.id,
+        )
+        session.add(overlay)
+        session.flush()
+        return overlay.id
+
+
+def test_user_cannot_create_blueprint_with_other_users_private_overlay(user_client) -> None:
+    foreign_overlay_id = _create_other_users_private_overlay()
+    payload = {
+        "name": "bad",
+        "arguments": [],
+        "config": [],
+        "overlay_ids": [foreign_overlay_id],
+    }
+
+    response = user_client.post(
+        "/blueprints",
+        data=json.dumps(payload),
+        content_type="application/json",
+        headers={"X-CSRF-Token": "test-token"},
+    )
+
+    assert response.status_code == 403
+
+
+def test_user_cannot_update_blueprint_with_other_users_private_overlay(user_client) -> None:
+    foreign_overlay_id = _create_other_users_private_overlay()
+    create = user_client.post(
+        "/blueprints",
+        data={"name": "comp", "arguments": "", "config": "", "overlay_ids": ["1"]},
+        headers={"X-CSRF-Token": "test-token"},
+    )
+    assert create.status_code == 302
+
+    response = user_client.post(
+        "/blueprints/1",
+        data={
+            "name": "edited",
+            "arguments": "",
+            "config": "",
+            "overlay_ids": [str(foreign_overlay_id)],
+        },
+        headers={"X-CSRF-Token": "test-token"},
+    )
+
+    assert response.status_code == 403
+
+
+def test_user_can_create_blueprint_with_system_overlay(user_client) -> None:
+    payload = {
+        "name": "system-ok",
+        "arguments": [],
+        "config": [],
+        "overlay_ids": [1],
+    }
+
+    response = user_client.post(
+        "/blueprints",
+        data=json.dumps(payload),
+        content_type="application/json",
+        headers={"X-CSRF-Token": "test-token"},
+    )
+
+    assert response.status_code == 201
+    blueprint_id = response.get_json()["id"]
+    with session_scope() as session:
+        link = session.query(BlueprintOverlay).filter_by(blueprint_id=blueprint_id, overlay_id=1).one()
+        assert link.position == 0
+
+
 def test_delete_blueprint_blocked_when_in_use(linked_blueprint) -> None:
    client, blueprint_id = linked_blueprint
    response = client.delete(f"/blueprints/{blueprint_id}", headers={"X-CSRF-Token": "test-token"})
--- a/l4d2web/tests/test_global_map_cache.py
+++ b/l4d2web/tests/test_global_map_cache.py
@ -0,0 +1,49 @@
+from pathlib import Path
+from zipfile import ZipFile
+
+from l4d2web.services.global_map_cache import (
+    extracted_vpk_md5,
+    global_overlay_cache_root,
+    safe_extract_zip_vpks,
+    source_cache_root,
+)
+
+
+def test_global_overlay_cache_paths(tmp_path, monkeypatch):
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+
+    assert global_overlay_cache_root() == tmp_path / "global_overlay_cache"
+    assert source_cache_root("l4d2center-maps") == tmp_path / "global_overlay_cache" / "l4d2center-maps"
+
+
+def test_safe_extract_zip_vpks_extracts_only_vpks(tmp_path):
+    archive = tmp_path / "maps.zip"
+    with ZipFile(archive, "w") as zf:
+        zf.writestr("FatalFreight.vpk", b"vpk-bytes")
+        zf.writestr("readme.txt", b"ignore")
+
+    out_dir = tmp_path / "out"
+    files = safe_extract_zip_vpks(archive, out_dir)
+
+    assert files == [out_dir / "FatalFreight.vpk"]
+    assert (out_dir / "FatalFreight.vpk").read_bytes() == b"vpk-bytes"
+    assert not (out_dir / "readme.txt").exists()
+
+
+def test_safe_extract_zip_vpks_rejects_path_traversal(tmp_path):
+    archive = tmp_path / "bad.zip"
+    with ZipFile(archive, "w") as zf:
+        zf.writestr("../evil.vpk", b"bad")
+
+    try:
+        safe_extract_zip_vpks(archive, tmp_path / "out")
+    except ValueError as exc:
+        assert "unsafe archive member" in str(exc)
+    else:
+        raise AssertionError("path traversal must fail")
+
+
+def test_extracted_vpk_md5(tmp_path):
+    p = tmp_path / "x.vpk"
+    p.write_bytes(b"abc")
+    assert extracted_vpk_md5(p) == "900150983cd24fb0d6963f7d28e17f72"
--- a/l4d2web/tests/test_global_map_sources.py
+++ b/l4d2web/tests/test_global_map_sources.py
@ -0,0 +1,65 @@
+from l4d2web.services.global_map_sources import (
+    GlobalMapManifestItem,
+    parse_cedapug_custom_html,
+    parse_l4d2center_csv,
+)
+
+
+def test_parse_l4d2center_csv_semicolon_manifest():
+    raw = """Name;Size;md5;Download link
+carriedoff.vpk;128660532;0380e12c57156574e17a96da1252cf21;https://l4d2center.com/maps/servers/carriedoff.7z
+"""
+
+    items = parse_l4d2center_csv(raw)
+
+    assert items == [
+        GlobalMapManifestItem(
+            item_key="carriedoff.vpk",
+            display_name="carriedoff.vpk",
+            download_url="https://l4d2center.com/maps/servers/carriedoff.7z",
+            expected_vpk_name="carriedoff.vpk",
+            expected_size=128660532,
+            expected_md5="0380e12c57156574e17a96da1252cf21",
+        )
+    ]
+
+
+def test_parse_l4d2center_rejects_missing_header():
+    try:
+        parse_l4d2center_csv("bad,data\n")
+    except ValueError as exc:
+        assert "Name;Size;md5;Download link" in str(exc)
+    else:
+        raise AssertionError("bad header must fail")
+
+
+def test_parse_cedapug_custom_html_extracts_relative_zip_links():
+    html = """
+    <script>renderCustomMapDownloads([
+      ["c1m1_hotel","<span style='color: #977d4c;'>Dead Center<\\/span>"],
+      ["l4d2_ff01_woods","<span style='color: #854C34;'>Fatal Freight<\\/span>","\\/maps\\/FatalFreight.zip"],
+      ["external","External","https://steamcommunity.com/sharedfiles/filedetails/?id=123"]
+    ])</script>
+    """
+
+    items = parse_cedapug_custom_html(html)
+
+    assert items == [
+        GlobalMapManifestItem(
+            item_key="FatalFreight.zip",
+            display_name="Fatal Freight",
+            download_url="https://cedapug.com/maps/FatalFreight.zip",
+            expected_vpk_name="",
+            expected_size=None,
+            expected_md5="",
+        )
+    ]
+
+
+def test_parse_cedapug_custom_html_rejects_missing_data():
+    try:
+        parse_cedapug_custom_html("<html></html>")
+    except ValueError as exc:
+        assert "renderCustomMapDownloads" in str(exc)
+    else:
+        raise AssertionError("missing embedded data must fail")
--- a/l4d2web/tests/test_global_overlay_builders.py
+++ b/l4d2web/tests/test_global_overlay_builders.py
@ -0,0 +1,89 @@
+import os
+from pathlib import Path
+
+from l4d2web.db import init_db, session_scope
+from l4d2web.models import GlobalOverlayItem, GlobalOverlayItemFile, GlobalOverlaySource, Overlay
+from l4d2web.services.overlay_builders import BUILDERS
+
+
+def seed_source(tmp_path: Path, monkeypatch) -> int:
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'builder.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+    cache_vpk = tmp_path / "global_overlay_cache" / "l4d2center-maps" / "vpks" / "carriedoff.vpk"
+    cache_vpk.parent.mkdir(parents=True, exist_ok=True)
+    cache_vpk.write_bytes(b"vpk")
+    with session_scope() as db:
+        overlay = Overlay(name="l4d2center-maps", path="7", type="l4d2center_maps", user_id=None)
+        db.add(overlay)
+        db.flush()
+        source = GlobalOverlaySource(
+            overlay_id=overlay.id,
+            source_key="l4d2center-maps",
+            source_type="l4d2center_csv",
+            source_url="https://l4d2center.com/maps/servers/index.csv",
+        )
+        db.add(source)
+        db.flush()
+        item = GlobalOverlayItem(
+            source_id=source.id,
+            item_key="carriedoff.vpk",
+            display_name="carriedoff.vpk",
+            download_url="https://example.invalid/carriedoff.7z",
+            expected_vpk_name="carriedoff.vpk",
+        )
+        db.add(item)
+        db.flush()
+        db.add(
+            GlobalOverlayItemFile(
+                item_id=item.id,
+                vpk_name="carriedoff.vpk",
+                cache_path="l4d2center-maps/vpks/carriedoff.vpk",
+                size=3,
+                md5="",
+            )
+        )
+        db.flush()
+        return overlay.id
+
+
+def test_registry_contains_global_map_builders():
+    assert "l4d2center_maps" in BUILDERS
+    assert "cedapug_maps" in BUILDERS
+
+
+def test_global_builder_creates_absolute_symlink(tmp_path, monkeypatch):
+    overlay_id = seed_source(tmp_path, monkeypatch)
+    out: list[str] = []
+    err: list[str] = []
+    with session_scope() as db:
+        overlay = db.query(Overlay).filter_by(id=overlay_id).one()
+        BUILDERS["l4d2center_maps"].build(overlay, on_stdout=out.append, on_stderr=err.append, should_cancel=lambda: False)
+
+    link = tmp_path / "overlays" / "7" / "left4dead2" / "addons" / "carriedoff.vpk"
+    assert link.is_symlink()
+    assert os.path.isabs(os.readlink(link))
+    assert link.resolve() == (tmp_path / "global_overlay_cache" / "l4d2center-maps" / "vpks" / "carriedoff.vpk").resolve()
+    assert any("global overlay" in line for line in out)
+
+
+def test_global_builder_removes_obsolete_managed_symlink_but_keeps_foreign(tmp_path, monkeypatch):
+    overlay_id = seed_source(tmp_path, monkeypatch)
+    addons = tmp_path / "overlays" / "7" / "left4dead2" / "addons"
+    addons.mkdir(parents=True, exist_ok=True)
+    foreign_target = tmp_path / "foreign.vpk"
+    foreign_target.write_bytes(b"foreign")
+    os.symlink(str(foreign_target), addons / "foreign.vpk")
+
+    with session_scope() as db:
+        overlay = db.query(Overlay).filter_by(id=overlay_id).one()
+        BUILDERS["l4d2center_maps"].build(overlay, on_stdout=lambda line: None, on_stderr=lambda line: None, should_cancel=lambda: False)
+        source = db.query(GlobalOverlaySource).filter_by(source_key="l4d2center-maps").one()
+        db.query(GlobalOverlayItem).filter_by(source_id=source.id).delete()
+
+    with session_scope() as db:
+        overlay = db.query(Overlay).filter_by(id=overlay_id).one()
+        BUILDERS["l4d2center_maps"].build(overlay, on_stdout=lambda line: None, on_stderr=lambda line: None, should_cancel=lambda: False)
+
+    assert not (addons / "carriedoff.vpk").exists()
+    assert (addons / "foreign.vpk").is_symlink()
--- a/l4d2web/tests/test_global_overlay_cli.py
+++ b/l4d2web/tests/test_global_overlay_cli.py
@ -0,0 +1,19 @@
+from l4d2web.app import create_app
+from l4d2web.db import init_db, session_scope
+from l4d2web.models import Job
+
+
+def test_refresh_global_overlays_cli_enqueues_system_job(tmp_path, monkeypatch):
+    db_url = f"sqlite:///{tmp_path/'cli.db'}"
+    monkeypatch.setenv("DATABASE_URL", db_url)
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    app = create_app({"TESTING": True, "DATABASE_URL": db_url, "SECRET_KEY": "test"})
+    init_db()
+
+    result = app.test_cli_runner().invoke(args=["refresh-global-overlays"])
+
+    assert result.exit_code == 0
+    assert "queued refresh_global_overlays job" in result.output
+    with session_scope() as db:
+        job = db.query(Job).filter_by(operation="refresh_global_overlays").one()
+        assert job.user_id is None
--- a/l4d2web/tests/test_global_overlay_models.py
+++ b/l4d2web/tests/test_global_overlay_models.py
@ -0,0 +1,154 @@
+from sqlalchemy.exc import IntegrityError
+
+from l4d2web.db import init_db, session_scope
+from l4d2web.models import (
+    GlobalOverlayItem,
+    GlobalOverlayItemFile,
+    GlobalOverlaySource,
+    Job,
+    Overlay,
+    User,
+)
+
+
+def test_system_job_allows_null_user_id(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'models.db'}")
+    init_db()
+
+    with session_scope() as db:
+        job = Job(
+            user_id=None,
+            server_id=None,
+            overlay_id=None,
+            operation="refresh_global_overlays",
+        )
+        db.add(job)
+        db.flush()
+        assert job.id is not None
+        assert job.user_id is None
+
+
+def test_global_overlay_source_uniqueness(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'sources.db'}")
+    init_db()
+
+    with session_scope() as db:
+        overlay = Overlay(
+            name="l4d2center-maps", path="1", type="l4d2center_maps", user_id=None
+        )
+        db.add(overlay)
+        db.flush()
+        db.add(
+            GlobalOverlaySource(
+                overlay_id=overlay.id,
+                source_key="l4d2center-maps",
+                source_type="l4d2center_csv",
+                source_url="https://l4d2center.com/maps/servers/index.csv",
+            )
+        )
+
+    try:
+        with session_scope() as db:
+            other = Overlay(
+                name="cedapug-maps", path="2", type="cedapug_maps", user_id=None
+            )
+            db.add(other)
+            db.flush()
+            db.add(
+                GlobalOverlaySource(
+                    overlay_id=other.id,
+                    source_key="l4d2center-maps",
+                    source_type="l4d2center_csv",
+                    source_url="https://example.invalid/duplicate",
+                )
+            )
+    except IntegrityError:
+        pass
+    else:
+        raise AssertionError("duplicate source_key must fail")
+
+
+def test_global_overlay_items_and_files_are_unique_per_parent(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'items.db'}")
+    init_db()
+
+    with session_scope() as db:
+        overlay = Overlay(name="cedapug-maps", path="1", type="cedapug_maps", user_id=None)
+        db.add(overlay)
+        db.flush()
+        source = GlobalOverlaySource(
+            overlay_id=overlay.id,
+            source_key="cedapug-maps",
+            source_type="cedapug_custom_page",
+            source_url="https://cedapug.com/custom",
+        )
+        db.add(source)
+        db.flush()
+        item = GlobalOverlayItem(
+            source_id=source.id,
+            item_key="FatalFreight.zip",
+            display_name="Fatal Freight",
+            download_url="https://cedapug.com/maps/FatalFreight.zip",
+            expected_vpk_name="FatalFreight.vpk",
+        )
+        db.add(item)
+        db.flush()
+        db.add(
+            GlobalOverlayItemFile(
+                item_id=item.id,
+                vpk_name="FatalFreight.vpk",
+                cache_path="cedapug-maps/vpks/FatalFreight.vpk",
+                size=123,
+                md5="",
+            )
+        )
+        item_id = item.id
+
+    try:
+        with session_scope() as db:
+            source = db.query(GlobalOverlaySource).filter_by(source_key="cedapug-maps").one()
+            db.add(
+                GlobalOverlayItem(
+                    source_id=source.id,
+                    item_key="FatalFreight.zip",
+                    display_name="Fatal Freight duplicate",
+                    download_url="https://cedapug.com/maps/FatalFreight.zip",
+                    expected_vpk_name="FatalFreight.vpk",
+                )
+            )
+    except IntegrityError:
+        pass
+    else:
+        raise AssertionError("duplicate item_key per source must fail")
+
+    try:
+        with session_scope() as db:
+            db.add(
+                GlobalOverlayItemFile(
+                    item_id=item_id,
+                    vpk_name="FatalFreight.vpk",
+                    cache_path="cedapug-maps/vpks/FatalFreight-copy.vpk",
+                    size=456,
+                    md5="",
+                )
+            )
+    except IntegrityError:
+        pass
+    else:
+        raise AssertionError("duplicate vpk_name per item must fail")
+
+
+def test_normal_user_rows_still_require_real_users(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'users.db'}")
+    init_db()
+
+    with session_scope() as db:
+        user = User(username="alice", password_digest="digest", admin=False)
+        db.add(user)
+        db.flush()
+        job = Job(user_id=user.id, server_id=None, operation="install", state="queued")
+        db.add(job)
+        db.flush()
+
+        assert job.id is not None
+        assert job.user_id == user.id
--- a/l4d2web/tests/test_global_overlay_refresh.py
+++ b/l4d2web/tests/test_global_overlay_refresh.py
@ -0,0 +1,69 @@
+from pathlib import Path
+
+from l4d2web.db import init_db, session_scope
+from l4d2web.models import GlobalOverlayItem, GlobalOverlayItemFile, GlobalOverlaySource
+from l4d2web.services.global_map_sources import GlobalMapManifestItem
+
+
+def test_refresh_global_overlays_updates_manifest_items_and_invokes_builders(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'refresh.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+
+    from l4d2web.services import global_overlay_refresh
+    monkeypatch.setattr(
+        global_overlay_refresh,
+        "fetch_l4d2center_manifest",
+        lambda: ("hash-center", [GlobalMapManifestItem("carriedoff.vpk", "carriedoff.vpk", "https://example.invalid/carriedoff.7z", "carriedoff.vpk", 3, "" )]),
+    )
+    monkeypatch.setattr(
+        global_overlay_refresh,
+        "fetch_cedapug_manifest",
+        lambda: ("hash-ceda", [GlobalMapManifestItem("FatalFreight.zip", "Fatal Freight", "https://example.invalid/FatalFreight.zip")]),
+    )
+
+    def fake_download_and_extract(source_key, item, *, should_cancel):
+        target = tmp_path / "global_overlay_cache" / source_key / "vpks" / (item.expected_vpk_name or item.item_key.replace(".zip", ".vpk"))
+        target.parent.mkdir(parents=True, exist_ok=True)
+        target.write_bytes(b"vpk")
+        return [(target.name, f"{source_key}/vpks/{target.name}", 3, "")], "etag", "last-modified", 3
+
+    built: list[str] = []
+    monkeypatch.setattr(global_overlay_refresh, "download_and_extract_item", fake_download_and_extract)
+    monkeypatch.setattr(global_overlay_refresh, "build_global_overlay", lambda overlay, **kwargs: built.append(overlay.name))
+
+    out: list[str] = []
+    result = global_overlay_refresh.refresh_global_overlays(on_stdout=out.append, on_stderr=out.append, should_cancel=lambda: False)
+
+    assert result == ["cedapug-maps", "l4d2center-maps"]
+    assert set(built) == {"cedapug-maps", "l4d2center-maps"}
+    with session_scope() as db:
+        assert db.query(GlobalOverlaySource).count() == 2
+        assert db.query(GlobalOverlayItem).count() == 2
+        assert db.query(GlobalOverlayItemFile).count() == 2
+
+
+def test_refresh_removes_items_absent_from_manifest(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'remove.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+
+    from l4d2web.services.global_overlays import ensure_global_overlays
+    from l4d2web.services import global_overlay_refresh
+
+    with session_scope() as db:
+        ensure_global_overlays(db)
+        source = db.query(GlobalOverlaySource).filter_by(source_key="l4d2center-maps").one()
+        item = GlobalOverlayItem(source_id=source.id, item_key="old.vpk", display_name="old.vpk", download_url="https://example.invalid/old.7z")
+        db.add(item)
+        db.flush()
+        db.add(GlobalOverlayItemFile(item_id=item.id, vpk_name="old.vpk", cache_path="l4d2center-maps/vpks/old.vpk", size=3))
+
+    monkeypatch.setattr(global_overlay_refresh, "fetch_l4d2center_manifest", lambda: ("empty-center", []))
+    monkeypatch.setattr(global_overlay_refresh, "fetch_cedapug_manifest", lambda: ("empty-ceda", []))
+    monkeypatch.setattr(global_overlay_refresh, "build_global_overlay", lambda overlay, **kwargs: None)
+
+    global_overlay_refresh.refresh_global_overlays(on_stdout=lambda line: None, on_stderr=lambda line: None, should_cancel=lambda: False)
+
+    with session_scope() as db:
+        assert db.query(GlobalOverlayItem).filter_by(item_key="old.vpk").count() == 0
--- a/l4d2web/tests/test_global_overlays.py
+++ b/l4d2web/tests/test_global_overlays.py
@ -0,0 +1,167 @@
+from sqlalchemy import select
+
+from l4d2web.db import init_db, session_scope
+from l4d2web.models import GlobalOverlaySource, Job, Overlay, User
+from l4d2web.services.global_overlays import (
+    enqueue_refresh_global_overlays,
+    ensure_global_overlays,
+    is_creatable_overlay_type,
+)
+
+
+def test_ensure_global_overlays_creates_singletons_and_directories(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'global_overlays.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+
+    with session_scope() as session:
+        created = ensure_global_overlays(session)
+        assert created == {"cedapug-maps", "l4d2center-maps"}
+
+        second = ensure_global_overlays(session)
+        assert second == set()
+
+        overlays = session.scalars(select(Overlay).order_by(Overlay.name)).all()
+        assert [overlay.name for overlay in overlays] == ["cedapug-maps", "l4d2center-maps"]
+        assert [overlay.type for overlay in overlays] == ["cedapug_maps", "l4d2center_maps"]
+        assert [overlay.user_id for overlay in overlays] == [None, None]
+        assert len({overlay.path for overlay in overlays}) == 2
+        for overlay in overlays:
+            assert (tmp_path / "overlays" / overlay.path).is_dir()
+
+        sources = session.scalars(select(GlobalOverlaySource).order_by(GlobalOverlaySource.source_key)).all()
+        assert [source.source_key for source in sources] == ["cedapug-maps", "l4d2center-maps"]
+        assert [source.source_type for source in sources] == [
+            "cedapug_custom_page",
+            "l4d2center_csv",
+        ]
+
+
+def test_ensure_global_overlays_repairs_existing_rows(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'global_overlay_repair.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+
+    with session_scope() as session:
+        overlay = Overlay(name="cedapug-maps", path="legacy", type="external", user_id=None)
+        session.add(overlay)
+        session.flush()
+        session.add(
+            GlobalOverlaySource(
+                overlay_id=overlay.id,
+                source_key="cedapug-maps",
+                source_type="wrong",
+                source_url="https://example.invalid/wrong",
+            )
+        )
+
+    (tmp_path / "overlays" / "legacy").mkdir(parents=True)
+
+    with session_scope() as session:
+        created = ensure_global_overlays(session)
+        assert created == {"l4d2center-maps"}
+
+        repaired = session.scalar(select(Overlay).where(Overlay.name == "cedapug-maps"))
+        assert repaired is not None
+        assert repaired.type == "cedapug_maps"
+        assert repaired.user_id is None
+        assert (tmp_path / "overlays" / repaired.path).is_dir()
+
+        source = session.scalar(
+            select(GlobalOverlaySource).where(GlobalOverlaySource.source_key == "cedapug-maps")
+        )
+        assert source is not None
+        assert source.source_type == "cedapug_custom_page"
+        assert source.source_url == "https://cedapug.com/custom"
+
+
+def test_ensure_global_overlays_does_not_hijack_private_overlay_name(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'global_overlay_private_name.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+
+    with session_scope() as session:
+        user = User(username="alice", password_digest="digest", admin=False)
+        session.add(user)
+        session.flush()
+        private = Overlay(
+            name="l4d2center-maps",
+            path="private-l4d2center",
+            type="workshop",
+            user_id=user.id,
+        )
+        session.add(private)
+        session.flush()
+        private_id = private.id
+        private_user_id = user.id
+
+    with session_scope() as session:
+        created = ensure_global_overlays(session)
+
+        assert created == {"cedapug-maps", "l4d2center-maps"}
+        private = session.scalar(select(Overlay).where(Overlay.id == private_id))
+        assert private is not None
+        assert private.user_id == private_user_id
+        assert private.type == "workshop"
+        assert private.path == "private-l4d2center"
+
+        system = session.scalar(
+            select(Overlay).where(Overlay.name == "l4d2center-maps", Overlay.user_id.is_(None))
+        )
+        assert system is not None
+        assert system.id != private_id
+        assert system.type == "l4d2center_maps"
+        assert (tmp_path / "overlays" / system.path).is_dir()
+
+        source = session.scalar(
+            select(GlobalOverlaySource).where(GlobalOverlaySource.source_key == "l4d2center-maps")
+        )
+        assert source is not None
+        assert source.overlay_id == system.id
+
+
+def test_enqueue_refresh_global_overlays_coalesces_active_jobs(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'refresh_jobs.db'}")
+    init_db()
+
+    for state in ("queued", "running", "cancelling"):
+        with session_scope() as session:
+            session.query(Job).delete()
+            existing = Job(
+                user_id=7,
+                server_id=None,
+                overlay_id=None,
+                operation="refresh_global_overlays",
+                state=state,
+            )
+            session.add(existing)
+            session.flush()
+            existing_id = existing.id
+
+            job = enqueue_refresh_global_overlays(session, user_id=None)
+            assert job.id == existing_id
+            assert session.query(Job).filter_by(operation="refresh_global_overlays").count() == 1
+
+
+def test_enqueue_refresh_global_overlays_creates_system_job(tmp_path, monkeypatch):
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'refresh_system_job.db'}")
+    init_db()
+
+    with session_scope() as session:
+        job = enqueue_refresh_global_overlays(session, user_id=None)
+
+        assert job.id is not None
+        assert job.user_id is None
+        assert job.server_id is None
+        assert job.overlay_id is None
+        assert job.operation == "refresh_global_overlays"
+        assert job.state == "queued"
+
+
+def test_is_creatable_overlay_type_policy():
+    assert is_creatable_overlay_type("workshop", admin=False) is True
+    assert is_creatable_overlay_type("external", admin=False) is False
+    assert is_creatable_overlay_type("external", admin=True) is True
+    assert is_creatable_overlay_type("workshop", admin=True) is True
+    assert is_creatable_overlay_type("l4d2center_maps", admin=True) is False
+    assert is_creatable_overlay_type("cedapug_maps", admin=True) is False
--- a/l4d2web/tests/test_job_logs.py
+++ b/l4d2web/tests/test_job_logs.py
@ -104,3 +104,28 @@ def test_sse_js_handles_job_log_custom_events() -> None:

    assert 'addEventListener("stdout"' in js
    assert 'addEventListener("stderr"' in js
+
+
+def test_system_job_logs_persist(tmp_path, monkeypatch):
+    from l4d2web.models import Job, JobLog
+    from l4d2web.services.job_worker import append_job_log
+
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'system-job-logs.db'}")
+    init_db()
+
+    with session_scope() as db:
+        job = Job(
+            user_id=None,
+            server_id=None,
+            operation="refresh_global_overlays",
+            state="queued",
+        )
+        db.add(job)
+        db.flush()
+
+        seq = append_job_log(db, job.id, "stdout", "queued by system timer")
+        db.flush()
+
+        row = db.query(JobLog).filter_by(job_id=job.id).one()
+        assert seq == 1
+        assert row.line == "queued by system timer"
--- a/l4d2web/tests/test_job_worker.py
+++ b/l4d2web/tests/test_job_worker.py
@ -700,3 +700,48 @@ def test_refresh_job_enqueues_build_overlay_without_locking_its_final_log(
    assert job.state == "succeeded"
    assert build_job is not None
    assert "enqueued build_overlay for 1 overlay(s)" in lines
+
+
+def test_refresh_global_overlays_blocks_install_build_refresh_and_servers() -> None:
+    from l4d2web.services.job_worker import SchedulerState, can_start
+
+    state = SchedulerState(refresh_global_overlays_running=True)
+    assert can_start(DummyJob(operation="install"), state) is False
+    assert can_start(DummyJob(operation="refresh_workshop_items"), state) is False
+    assert can_start(DummyJob(operation="build_overlay", overlay_id=1), state) is False
+    assert can_start(DummyJob(operation="start", server_id=1), state) is False
+
+
+def test_refresh_global_overlays_waits_for_active_work() -> None:
+    from l4d2web.services.job_worker import SchedulerState, can_start
+
+    assert can_start(DummyJob(operation="refresh_global_overlays"), SchedulerState(install_running=True)) is False
+    assert can_start(DummyJob(operation="refresh_global_overlays"), SchedulerState(refresh_running=True)) is False
+    state = SchedulerState()
+    state.running_overlays.add(1)
+    assert can_start(DummyJob(operation="refresh_global_overlays"), state) is False
+    state = SchedulerState()
+    state.running_servers.add(1)
+    assert can_start(DummyJob(operation="refresh_global_overlays"), state) is False
+
+
+def test_run_worker_once_dispatches_refresh_global_overlays(seeded_worker, monkeypatch):
+    from l4d2web.services import job_worker
+    from l4d2web.models import Job
+    from l4d2web.db import session_scope
+
+    called = []
+
+    def fake_refresh(*, on_stdout, on_stderr, should_cancel):
+        called.append("refresh")
+        on_stdout("global refresh complete")
+        return ["l4d2center-maps"]
+
+    monkeypatch.setattr(job_worker, "_run_refresh_global_overlays", fake_refresh)
+    with session_scope() as db:
+        job = Job(user_id=None, server_id=None, operation="refresh_global_overlays", state="queued")
+        db.add(job)
+
+    app, ids = seeded_worker
+    assert job_worker.run_worker_once() is True
+    assert called == ["refresh"]
--- a/l4d2web/tests/test_l4d2_facade.py
+++ b/l4d2web/tests/test_l4d2_facade.py
@ -258,3 +258,55 @@ def test_initialize_fails_fast_on_uncached_workshop_items(
    assert str(overlay_id) in msg or "ws" in msg
    # l4d2ctl initialize MUST NOT run when uncached items are present.
    assert all("initialize" not in cmd for cmd in invocations), invocations
+
+
+def test_initialize_fails_when_global_overlay_cache_file_missing(tmp_path, monkeypatch):
+    from l4d2web.db import init_db, session_scope
+    from l4d2web.models import (
+        Blueprint,
+        BlueprintOverlay,
+        GlobalOverlayItem,
+        GlobalOverlayItemFile,
+        GlobalOverlaySource,
+        Overlay,
+        Server,
+        User,
+    )
+    from l4d2web.services.l4d2_facade import initialize_server
+
+    monkeypatch.setenv("DATABASE_URL", f"sqlite:///{tmp_path/'facade-global.db'}")
+    monkeypatch.setenv("LEFT4ME_ROOT", str(tmp_path))
+    init_db()
+
+    with session_scope() as db:
+        user = User(username="alice", password_digest="digest")
+        db.add(user)
+        db.flush()
+        overlay = Overlay(name="l4d2center-maps", path="7", type="l4d2center_maps", user_id=None)
+        db.add(overlay)
+        db.flush()
+        source = GlobalOverlaySource(overlay_id=overlay.id, source_key="l4d2center-maps", source_type="l4d2center_csv", source_url="https://l4d2center.com/maps/servers/index.csv")
+        db.add(source)
+        db.flush()
+        item = GlobalOverlayItem(source_id=source.id, item_key="carriedoff.vpk", display_name="carriedoff.vpk", download_url="https://example.invalid/carriedoff.7z")
+        db.add(item)
+        db.flush()
+        db.add(GlobalOverlayItemFile(item_id=item.id, vpk_name="carriedoff.vpk", cache_path="l4d2center-maps/vpks/carriedoff.vpk", size=123))
+        blueprint = Blueprint(user_id=user.id, name="bp", arguments="[]", config="[]")
+        db.add(blueprint)
+        db.flush()
+        db.add(BlueprintOverlay(blueprint_id=blueprint.id, overlay_id=overlay.id, position=0))
+        server = Server(user_id=user.id, blueprint_id=blueprint.id, name="alpha", port=27015)
+        db.add(server)
+        db.flush()
+        server_id = server.id
+
+    monkeypatch.setattr("l4d2web.services.host_commands.run_command", lambda *args, **kwargs: None)
+
+    try:
+        initialize_server(server_id)
+    except RuntimeError as exc:
+        assert "carriedoff.vpk" in str(exc)
+        assert "l4d2center-maps" in str(exc)
+    else:
+        raise AssertionError("missing global overlay cache file must fail")
--- a/l4d2web/tests/test_overlays.py
+++ b/l4d2web/tests/test_overlays.py
@ -2,7 +2,7 @@ import pytest
 from l4d2web.app import create_app
 from l4d2web.auth import hash_password
 from l4d2web.db import init_db, session_scope
-from l4d2web.models import Blueprint, BlueprintOverlay, Overlay, User
+from l4d2web.models import Blueprint, BlueprintOverlay, GlobalOverlaySource, Overlay, User
 from l4d2web.services.security import validate_overlay_ref


@ -60,6 +60,16 @@ def test_user_can_view_overlay_catalog(user_client_with_overlay) -> None:
    assert "Create overlay" in text


+def test_non_admin_can_view_managed_global_system_overlay(user_client_with_overlay) -> None:
+    _create_managed_global_overlay()
+
+    response = user_client_with_overlay.get("/overlays")
+    text = response.get_data(as_text=True)
+
+    assert response.status_code == 200
+    assert "l4d2center-maps" in text
+
+
 def test_admin_can_view_overlay_edit_controls(admin_client) -> None:
    response = admin_client.get("/overlays")
    text = response.get_data(as_text=True)
@ -80,6 +90,16 @@ def test_admin_can_create_external_overlay(admin_client) -> None:
    assert response.headers["Location"].startswith("/overlays/")


+def test_admin_cannot_create_managed_global_overlay_type(admin_client) -> None:
+    response = admin_client.post(
+        "/overlays",
+        data={"name": "managed", "type": "l4d2center_maps"},
+        headers={"X-CSRF-Token": "test-token"},
+    )
+    assert response.status_code == 400
+    assert "unknown overlay type" in response.get_data(as_text=True)
+
+
@pytest.mark.parametrize("overlay_ref", [" standard", "standard ", "a//b", "a/", "./a", "a/.", "."])
 def test_overlay_ref_rejects_unsafe_components(overlay_ref: str) -> None:
    with pytest.raises(ValueError):
@ -92,7 +112,7 @@ def test_non_admin_cannot_create_external_overlay(user_client_with_overlay) -> N
        data={"name": "bad", "type": "external"},
        headers={"X-CSRF-Token": "test-token"},
    )
-    assert response.status_code == 403
+    assert response.status_code == 400


 def test_user_can_create_workshop_overlay(user_client_with_overlay) -> None:
@ -184,6 +204,62 @@ def test_admin_can_update_and_delete_overlay(admin_client) -> None:
    assert delete.status_code == 302


+def _create_managed_global_overlay() -> int:
+    with session_scope() as session:
+        overlay = Overlay(
+            name="l4d2center-maps",
+            path="managed-l4d2center",
+            type="l4d2center_maps",
+            user_id=None,
+        )
+        session.add(overlay)
+        session.flush()
+        session.add(
+            GlobalOverlaySource(
+                overlay_id=overlay.id,
+                source_key="l4d2center-maps",
+                source_type="l4d2center_csv",
+                source_url="https://l4d2center.com/maps/servers/index.csv",
+            )
+        )
+        return overlay.id
+
+
+def test_admin_cannot_update_managed_global_overlay(admin_client) -> None:
+    overlay_id = _create_managed_global_overlay()
+
+    response = admin_client.post(
+        f"/overlays/{overlay_id}",
+        data={"name": "renamed"},
+        headers={"X-CSRF-Token": "test-token"},
+    )
+
+    assert response.status_code == 403
+
+
+def test_admin_cannot_delete_managed_global_overlay(admin_client) -> None:
+    overlay_id = _create_managed_global_overlay()
+
+    response = admin_client.post(
+        f"/overlays/{overlay_id}/delete",
+        headers={"X-CSRF-Token": "test-token"},
+    )
+
+    assert response.status_code == 403
+
+
+def test_admin_overlay_detail_hides_edit_for_managed_global_overlay(admin_client) -> None:
+    overlay_id = _create_managed_global_overlay()
+
+    response = admin_client.get(f"/overlays/{overlay_id}")
+    text = response.get_data(as_text=True)
+
+    assert response.status_code == 200
+    assert f'action="/overlays/{overlay_id}"' not in text
+    assert "delete-overlay-modal" not in text
+
+
+
 def test_update_overlay_rejects_duplicate_name(admin_client) -> None:
    ids: list[int] = []
    for name in ("standard", "competitive"):
@ -235,6 +311,56 @@ def test_overlay_detail_page_lists_using_blueprints(admin_client) -> None:
    assert "Used by" in text


+def test_non_admin_overlay_detail_only_lists_own_using_blueprints(user_client_with_overlay) -> None:
+    overlay_id = _create_managed_global_overlay()
+    with session_scope() as session:
+        alice = session.query(User).filter_by(username="alice").one()
+        other = User(username="mallory", password_digest=hash_password("secret"), admin=False)
+        session.add(other)
+        session.flush()
+
+        own_bp = Blueprint(user_id=alice.id, name="own-bp", arguments="[]", config="[]")
+        other_bp = Blueprint(user_id=other.id, name="other-private-bp", arguments="[]", config="[]")
+        session.add_all([own_bp, other_bp])
+        session.flush()
+        session.add(BlueprintOverlay(blueprint_id=own_bp.id, overlay_id=overlay_id, position=0))
+        session.add(BlueprintOverlay(blueprint_id=other_bp.id, overlay_id=overlay_id, position=0))
+
+    response = user_client_with_overlay.get(f"/overlays/{overlay_id}")
+    text = response.get_data(as_text=True)
+
+    assert response.status_code == 200
+    assert "own-bp" in text
+    assert "other-private-bp" not in text
+
+
+def test_blueprint_edit_lists_system_and_owned_overlays_only(user_client_with_overlay) -> None:
+    system_overlay_id = _create_managed_global_overlay()
+    with session_scope() as session:
+        alice = session.query(User).filter_by(username="alice").one()
+        other = User(username="mallory", password_digest=hash_password("secret"), admin=False)
+        session.add(other)
+        session.flush()
+        foreign_overlay = Overlay(
+            name="other-private-workshop",
+            path="other-private-workshop",
+            type="workshop",
+            user_id=other.id,
+        )
+        blueprint = Blueprint(user_id=alice.id, name="alice-bp", arguments="[]", config="[]")
+        session.add_all([foreign_overlay, blueprint])
+        session.flush()
+        blueprint_id = blueprint.id
+
+    response = user_client_with_overlay.get(f"/blueprints/{blueprint_id}")
+    text = response.get_data(as_text=True)
+
+    assert response.status_code == 200
+    assert "l4d2center-maps" in text
+    assert f'value="{system_overlay_id}"' in text
+    assert "other-private-workshop" not in text
+
+
 def test_overlay_detail_page_404_when_missing(admin_client) -> None:
    response = admin_client.get("/overlays/999")
    assert response.status_code == 404
@ -251,6 +377,36 @@ def test_overlay_detail_hides_edit_for_non_admin_external(user_client_with_overl
    assert "delete-overlay-modal" not in text


+def test_non_admin_cannot_view_other_users_private_non_workshop_overlay(user_client_with_overlay) -> None:
+    with session_scope() as session:
+        other = User(username="mallory", password_digest=hash_password("secret"), admin=False)
+        session.add(other)
+        session.flush()
+        overlay = Overlay(
+            name="private-external",
+            path="private-external",
+            type="external",
+            user_id=other.id,
+        )
+        session.add(overlay)
+        session.flush()
+        overlay_id = overlay.id
+
+    response = user_client_with_overlay.get(f"/overlays/{overlay_id}")
+
+    assert response.status_code == 403
+
+
+def test_managed_global_overlay_detail_shows_source_url(admin_client) -> None:
+    overlay_id = _create_managed_global_overlay()
+
+    response = admin_client.get(f"/overlays/{overlay_id}")
+    text = response.get_data(as_text=True)
+
+    assert response.status_code == 200
+    assert "https://l4d2center.com/maps/servers/index.csv" in text
+
+
 def test_overlay_update_redirects_to_detail(admin_client) -> None:
    create = admin_client.post(
        "/overlays",
@ -293,3 +449,9 @@ def test_delete_overlay_rejects_in_use_overlay(admin_client) -> None:
    )

    assert response.status_code == 409
+
+
+def test_admin_can_enqueue_refresh_global_overlays(admin_client):
+    response = admin_client.post("/admin/global-overlays/refresh", headers={"X-CSRF-Token": "test-token"})
+    assert response.status_code == 302
+    assert response.headers["Location"] == "/admin/jobs"
--- a/l4d2web/tests/test_pages.py
+++ b/l4d2web/tests/test_pages.py
@ -457,3 +457,56 @@ def test_blueprint_detail_has_ordered_overlay_form(auth_client_with_server) -> N
    assert 'name="config"' in text
    assert 'name="overlay_ids"' in text
    assert 'name="overlay_position_1"' in text
+
+
+def test_admin_jobs_page_renders_system_job(tmp_path, monkeypatch) -> None:
+    db_url = f"sqlite:///{tmp_path/'admin-system-job.db'}"
+    monkeypatch.setenv("DATABASE_URL", db_url)
+    app = create_app({"TESTING": True, "DATABASE_URL": db_url, "SECRET_KEY": "test"})
+    init_db()
+
+    with session_scope() as session:
+        admin = User(username="admin", password_digest=hash_password("secret"), admin=True)
+        session.add(admin)
+        session.flush()
+        admin_id = admin.id
+
+    admin_client = app.test_client()
+    with admin_client.session_transaction() as sess:
+        sess["user_id"] = admin_id
+
+    with session_scope() as db:
+        db.add(Job(user_id=None, server_id=None, operation="refresh_global_overlays", state="queued"))
+
+    response = admin_client.get("/admin/jobs")
+    text = response.get_data(as_text=True)
+
+    assert response.status_code == 200
+    assert "refresh_global_overlays" in text
+    assert "system" in text
+
+
+def test_non_admin_cannot_view_system_job(tmp_path, monkeypatch) -> None:
+    db_url = f"sqlite:///{tmp_path/'non-admin-system-job.db'}"
+    monkeypatch.setenv("DATABASE_URL", db_url)
+    app = create_app({"TESTING": True, "DATABASE_URL": db_url, "SECRET_KEY": "test"})
+    init_db()
+
+    with session_scope() as session:
+        user = User(username="alice", password_digest=hash_password("secret"), admin=False)
+        session.add(user)
+        session.flush()
+        user_id = user.id
+
+    user_client = app.test_client()
+    with user_client.session_transaction() as sess:
+        sess["user_id"] = user_id
+
+    with session_scope() as db:
+        job = Job(user_id=None, server_id=None, operation="refresh_global_overlays", state="queued")
+        db.add(job)
+        db.flush()
+        job_id = job.id
+
+    response = user_client.get(f"/jobs/{job_id}")
+    assert response.status_code == 403