docs: Document audit logging

docs/administration/audit-logging.md

@@ -0,0 +1,142 @@
+---
+date: "2026-09-12T00:00:00+00:00"
+slug: "audit-logging"
+sidebar_position: 41
+aliases:
+  - /en-us/audit-logging
+---
+
+# Audit Logging
+
+Gitea can record security-relevant events as structured audit records: each
+event has an `action`, `actor`, `scope`, `origin`, `message` and a JSON
+`metadata` blob. Recording is **off by default** and does not change request
+behavior when it is disabled.
+
+This is separate from the application, router and access logs described in
+[Logging Configuration](logging-config.md). Those logs are for operations and
+debugging. The audit log is a durable trail of who changed what.
+
+## Enable recording
+
+Set `[audit].RECORD_OUTPUT` to `database` in `app.ini` and restart Gitea:
+
+```ini
+[audit]
+RECORD_OUTPUT = database
+RETENTION_DAYS = 30
+```
+
+Invalid values of `RECORD_OUTPUT` fall back to `disabled`. See the
+[configuration cheat sheet](config-cheat-sheet.md#audit-audit) for every option.
+
+With Docker, the same settings can be applied as
+`GITEA__audit__RECORD_OUTPUT=database` and `GITEA__audit__RETENTION_DAYS=30`
+before Gitea writes them into `app.ini`.
+
+## View events
+
+The Audit Log page is always available. When recording is disabled, it shows a
+warning and still lists any events that were stored earlier.
+
+| Audience | Location | Events shown |
+| --- | --- | --- |
+| Site administrators | Site administration → Monitoring → Audit Log (`/-/admin/monitor/audit_logs`) | Every event |
+| Signed-in users | User settings → Audit Log (`/user/settings/audit_logs`) | Events scoped to that user |
+| Organization owners | Organization settings → Audit Log (`/<org>/settings/audit_logs`) | Events scoped to that organization |
+| Repository administrators | Repository settings → Audit Log (`/<owner>/<repo>/settings/audit_logs`) | Events scoped to that repository |
+
+Each listing can be filtered by actor (username), action and origin, and sorted
+by timestamp. Action filters accept an exact action or a family prefix such as
+`user:impersonation` or `repository:webhook`.
+
+Site administrators can download the current filtered result as JSONL
+(newline-delimited JSON) from **Export JSONL**. The file name is
+`gitea-audit-log-<timestamp>.jsonl`.
+
+## Event shape
+
+A recorded event contains:
+
+- **Action**: a stable, colon-separated identifier such as `repository:archive`
+  or `user:accesstoken:add`.
+- **Actor**: the user who performed the action. Actions taken while impersonating
+  a user record both the impersonator and the impersonated user.
+- **Actor credential**: when the request authenticated with a named credential,
+  the event stores its kind and id, never the secret. Typical values:
+  `access-token:<id>`, `oauth2-grant:<id>`, `gitea-actions:<task id>`,
+  `deploy-key:<key id>`.
+- **Scope**: the affected unit — `user`, `organization`, `repository` or
+  `system` (instance-wide).
+- **Origin**: how the action was initiated — `ui`, `api`, `cli` or `system`.
+- **Message**: a human-readable sentence rendered from a per-action template.
+- **Metadata**: extra fields that fill the message template (token name, new
+  visibility, and so on). Secrets and token values are not stored.
+- **IP address**: the client address of the request, when one exists.
+- **Timestamp**: when the event was recorded.
+
+An exported JSONL line looks like:
+
+```json
+{"action":"repository:archive","actor":{"type":"user","id":1,"name":"alice"},"scope":{"type":"repository","id":42,"name":"org/repo"},"message":"Archived repository org/repo.","time":"2026-09-12T11:00:00Z","ip_address":"203.0.113.10","origin":"ui"}
+```
+
+The `system:startup` message is kept stable across Gitea versions so operators
+can parse it: `System started [Gitea {version}]`.
+
+## Actors and origins
+
+Most web and API requests pick up the signed-in user automatically.
+
+Some entry points have no signed-in user. Those events use a dedicated actor:
+
+- `CLI` for `gitea` command-line operations
+- `AuthenticationSource` for authentication-source syncs and related background
+  work
+- `Unknown` if the actor cannot be resolved; the event is still recorded
+
+Cron tasks and other background work use origin `system`. Git hooks and similar
+non-interactive paths are attributed the same way.
+
+## What is recorded
+
+Events cover security-relevant changes, grouped by action family:
+
+- **User**: create and delete, name, password, visibility, emails, 2FA,
+  WebAuthn, OpenID, external logins, access tokens, OAuth2 applications and
+  grants, SSH/GPG/principal keys, secrets, webhooks, impersonation, failed
+  two-factor authentication
+- **Organization**: create and delete, name, visibility, members, teams,
+  OAuth2 applications, secrets, webhooks
+- **Repository**: create, fork, archive, delete, rename, visibility, transfer,
+  mirrors, signing verification, collaborators and teams, default branch,
+  branch and tag protection, deploy keys, webhooks, secrets
+- **Issues, pull requests, projects and wiki**: create, update, delete, comments
+  and merges
+- **Actions**: enable, disable and dispatch a workflow
+- **System**: startup and shutdown, instance-wide webhooks, authentication
+  sources, instance-wide OAuth2 applications
+
+Recording never fails the request that triggered it. A write error is logged
+and the original operation continues.
+
+## What is not recorded
+
+- Read-only access such as browsing, clone, fetch or API GET requests
+- Successful password or SSH logins (use the [access log](logging-config.md)
+  and [Fail2ban Setup](fail2ban-setup.md) for authentication traffic)
+- Token or secret values
+- Which SSH key a real user pushed with (deploy keys are named; ordinary SSH
+  user pushes are not)
+
+## Retention
+
+`RETENTION_DAYS` (default **30**) is the age after which recorded events are
+eligible for deletion. Set it to `0` to keep events forever.
+
+Cleanup is performed by the `cron.delete_old_audit_events` task (`SCHEDULE`
+defaults to `@every 24h`, `OLDER_THAN` defaults to `[audit].RETENTION_DAYS`).
+The task is registered only while `RECORD_OUTPUT` records events **and**
+`RETENTION_DAYS` is greater than `0`. Turning recording off therefore also
+stops pruning; existing rows stay until you delete them or turn recording back
+on.

docs/administration/config-cheat-sheet.md

@@ -656,6 +656,11 @@ And the following unique queues:
   - CIDR list: `1.2.3.0/8` for IPv4 and `2001:db8::/32` for IPv6
   - Wildcard hosts: `*.mydomain.com`, `192.168.100.*`
 
+## Audit (`audit`)
+
+- `RECORD_OUTPUT`: **disabled**: Where security-relevant events are recorded. `disabled` records nothing. `database` writes events to the `audit_event` table and shows them in the admin, organization, repository and user settings. Invalid values fall back to `disabled`. See [Audit Logging](audit-logging.md).
+- `RETENTION_DAYS`: **30**: Days to keep recorded events. `0` keeps them forever. Pruning is done by `cron.delete_old_audit_events`. That task is only registered while `RECORD_OUTPUT` records events and `RETENTION_DAYS` is greater than `0`.
+
 ## Camo (`camo`)
 
 - `ENABLED`: **false**: Enable media proxy, we support images only at the moment.
@@ -1198,6 +1203,16 @@ Synchronize external user data (only LDAP user synchronization is supported)
 - `SCHEDULE`: **@every 168h**: Cron syntax to set how often to check.
 - `OLDER_THAN`: **8760h**: any action older than this expression will be deleted from database, suggest using `8760h` (1 year) because that's the max length of heatmap.
 
+#### Cron - Delete old audit events (`cron.delete_old_audit_events`)
+
+Deletes audit events older than the retention period. The task is only registered when `[audit].RECORD_OUTPUT` records events and `[audit].RETENTION_DAYS` is greater than `0`. See [Audit Logging](audit-logging.md).
+
+- `ENABLED`: **true**: Enable service.
+- `RUN_AT_START`: **false**: Run tasks at start up time (if ENABLED).
+- `NOTICE_ON_SUCCESS`: **false**: Set to true to switch on success notices.
+- `SCHEDULE`: **@every 24h**: Cron syntax to set how often to check.
+- `OLDER_THAN`: **720h**: any audit event older than this expression will be deleted from the database. Defaults to `[audit].RETENTION_DAYS`.
+
 #### Cron -  Check for new Gitea versions (`cron.update_checker`)
 
 - `ENABLED`: **true**: Enable service.

docs/administration/logging-config.md

@@ -16,6 +16,8 @@ The logging configuration of Gitea mainly consists of 3 types of components:
 
 There is a fully functional log output by default, so it is not necessary to define one.
 
+Security-relevant events (repository transfers, token changes, impersonation, and similar) are recorded separately. See [Audit Logging](audit-logging.md).
+
 ## Collecting Logs for Help
 
 To collect logs for help and issue report, see [Support Options](help/support.md).

docs/index.md

@@ -43,7 +43,7 @@ You can try it out using [the online demo](https://demo.gitea.com).
 
 - **Security**
 
-  Gitea places a strong emphasis on security, offering features such as user permission management, access control lists, and more to ensure the security of code and data.
+  Gitea places a strong emphasis on security, offering features such as user permission management, access control lists, [audit logging](administration/audit-logging.md), and more to ensure the security of code and data.
 
 - **Code Review**
 

docs/installation/comparison.md

@@ -34,6 +34,7 @@ _Symbols used in table:_
 | Telemetry                                        | **✘**                                               | ✓         | ✓         | ✓         | ✓         | ✘            | ✘            |
 | Third-party render tool support                  | ✓                                                   | ✘         | ✘         | ✘         | ✓         | ✘            | ✘            |
 | WebAuthn (2FA)                                   | ✓                                                   | ✓         | ✓         | ✓         | ✓         | ✘            | ✓            |
+| Audit log                                        | ✓                                                   | ✓         | ⁄         | ✓         | ✓         | ?            | ?            |
 | Extensive API                                    | ✓                                                   | ✓         | ✓         | ✓         | ✓         | ✓            | ✓            |
 | Built-in Package/Container Registry              | ✓                                                   | ✓         | ✓         | ✓         | ✘         | ✘            | ✘            |
 | Sync commits to an external repo (push mirror)   | ✓                                                   | ✘         | ✓         | ✓         | ✘         | ✓            | ✓            |