computer-playbook/docs/contributing/design/role/services/mcp/delegation.md

MCP User Delegation 🪪

auth_subject: user and auth: oidc claim that an MCP call executes with the requesting end user's permissions. A delegation: block records the audit that backs the claim; without it, test_mcp_schema.py rejects the role.

Declaring it

mcp:
  auth: oidc
  auth_subject: user
  delegation:
    verified_version: 1.2.3
    source_url: https://example.invalid/project/tree/v1.2.3/path/to/auth
    refresh: true
    revocation: true
    audience_binding: true

All three booleans MUST be true, and verified_version MUST name the exact tag or digest the source was read at. A newer upstream release is not evidence for the deployed pin.

Client audit

Client	Pin	Delegation	Evidence
web-app-openwebui	0.11.0	capable	ToolServerConnection.auth_type: system_oauth resolves the caller's token through oauth_manager.get_oauth_token(user.id, oauth_session_id) and presents it as the Bearer
web-app-hermes	v2026.7.20	incapable	config.yaml.j2 renders one static Authorization header per server; no user session exists at render time
web-app-openclaw	2026.7.1	incapable	openclaw.json.j2 renders one static Authorization header per server
web-app-flowise	3.1.3	incapable	Registry entries bind to a workspace and store one encrypted custom header, not a per-user token

Provider audit

Provider	Pin	Delegation	Evidence
web-app-baserow	2.3.1	incapable	The endpoint authenticates a Baserow app password bound to the endpoint owner
web-app-gitea	sidecar	incapable	The sidecar authenticates a Gitea token
web-app-gitlab	18.x	incapable	The endpoint authenticates a GitLab PAT or GitLab-issued OAuth token, not a platform OIDC access token
web-app-homeassistant	2026.7	incapable	The endpoint authenticates a Home Assistant long-lived access token
web-app-jenkins	plugin	incapable	The endpoint authenticates Jenkins basic auth
web-app-mattermost	plugin	incapable	The endpoint authenticates a Mattermost bot token
web-app-moodle	plugin	incapable	The endpoint authenticates a Moodle web-service token
web-app-nextcloud	ExApp	incapable	The endpoint authenticates a Nextcloud app password bound to one user

No pair of a capable client and a capable provider exists at the current pins, so every provider declares auth_subject: service_account.

The renderable path

svc-ai-mcp-adapter validates the platform's OIDC access token, so an adapter-backed provider is the one surface that can declare auth: oidc with auth_subject: user. Only Open WebUI can consume it:

• mcp_authorization raises for auth: oidc, because a rendered config cannot carry a caller's token, and mcp_authorization_is_renderable returns false so the static-config clients drop the server instead of presenting a wrong secret.
• mcp_tool_server_connections emits auth_type: system_oauth with an empty key for those servers, so Open WebUI resolves the caller's own token per request.

See Also

• Service block vocabulary: mcp.md