Eight server roles declare an `mcp` RBAC role, so the platform mints
roles/<app>/mcp and the administrator joins it. Open WebUI now honours those
groups instead of flattening them to user/admin, and each MCP tool server is
restricted to the group of the role that serves it.
The grant cannot be rendered: Open WebUI matches it against a group id that
insert_new_group mints as a fresh UUID, so tasks/01_mcp.yml resolves the group
after the container is up and writes the grant through the admin API, the way
every instance-minted credential in this repository is provisioned.
Entries render disabled. An empty access_grants is not 'nobody', Open WebUI
reads it as every administrator, and ENABLE_PERSISTENT_CONFIG=false makes the
env authoritative again on every start. Enabling only together with the grant
keeps the fallback at no access rather than too much.
The provisioning account is the role-internal openwebui-api-bot, never a
platform identity: OAUTH_MERGE_ACCOUNTS_BY_EMAIL ships disabled and an OIDC
login whose email a local account already holds is refused, so seeding a
person's address would lock them out.
Known limits are documented rather than claimed away: a bare restart leaves MCP
off until the next deploy, a user's roles list carries no application context so
roles: [mcp] grants every deployed mcp group at once, and Open WebUI drops a
stale membership only while the groups claim is non-empty.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
The first MCP server role: where the agent roles consume tools, this one
offers them. Its services.mcp block declares an internal streamable-HTTP
endpoint gated on an agent being deployed, so the surface only exists
when something can use it, and it stays read-only because a privileged
auth subject must not carry mutating tools.
Home Assistant rejects any request carrying X-Forwarded-For from an
undeclared proxy, answering 400 for every call behind the platform's
reverse proxy. The role therefore renders a configuration.yaml that
trusts the stack subnet, keeping default_config so mounting the file does
not drop the integrations Home Assistant generates on first start.
As a shared_net provider its compose file references its own network as
external, which nothing creates in compose mode, so the role pre-creates
it the way prometheus, minio and seaweedfs already do. The vhost declares
status_codes [200, 302, 405] because the health probe sends HEAD and the
hub answers 405.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
kevinveenbirkenbachandClaude Opus 5