@assemblyline-agents/mirror

Official Assembly Line connection plugin for Mirror. It gives each authenticated agent user an optional, separately authorized path to their mirrored source records and connected accounts.

Setup

Choose a stable public client id for the agent deployment and set:

MIRROR_OAUTH_CLIENT_ID=my-assembly-line-agent

Mirror accepts Assembly Line's OAuth Authorization Code flow with mandatory PKCE S256. The normal callback is:

https://YOUR-AGENT-HOST/assembly-line/connections/callback

The hosted service and MCP endpoint are used by default. Self-hosted deployments can set MIRROR_MCP_URL and, when OAuth is on a different origin, MIRROR_OAUTH_ISSUER. MIRROR_OAUTH_REDIRECT_URI overrides Assembly Line's normal callback only when necessary.

assembly-line add mirror agent

Scoped binding packets

For least-privilege setup, create an agent binding in Mirror's Agents UI, choose the exact provider accounts it may reach, and paste the generated binding packet into the agent's chat. The core pair tool is exposed by default whenever the agent has a live connection, and Assembly Line also advertises a host-side mirror__pair connection tool through discovery while Mirror is unauthorized. Either tool sends the packet's one-time claim secret only to the configured Mirror deployment, stores the returned access and refresh tokens in the connection grant store, and keeps the durable credentials out of the model and sandbox. If the Mirror definition cannot resolve on the runtime host (for example a missing package or unset env), pair reports that cause instead of disappearing.

The packet's API origin must match MIRROR_OAUTH_ISSUER, MIRROR_MCP_URL, or the connection's configured URL. Credential exchange requires HTTPS, except for loopback development. OAuth remains available as an alternative account authorization path.

The selected plugin exposes every reviewed Mirror tool. Gate or remove named actions through plugins.mirror.connections.mirror.approval or disable in agent.md.

Mirror still enforces its own account grants and exact-action approval system. When configured, Assembly Line approval is an additional outer gate.

The connection includes Mirror's read-only mirror.get_skill discovery tool. This returns Mirror's live, versioned action contract; it is not a local Assembly Line skill. Before requesting a provider mutation, pass its returned version and content hash to mirror.request_action. This keeps the agent's request shape synchronized with Mirror's reviewed action contract.

Connection events

Mirror event delivery uses the connection's existing binding grant. No separate automation token or signing-secret environment variable is required. Assembly Line registers and verifies the callback endpoint for its own Mirror binding. Set plugins.mirror.connections.mirror.events: false only when the agent must not receive Mirror events.

Connection-level event scope stays in Mirror. From the binding's Events section, the user chooses exactly which granted, event-capable provider connections may send source changes to the agent. The Assembly Line plugin never enables or disables those subscriptions.

Optional Mirror CLI

The MCP connection is the default and works without a CLI. CLI credential projection is executable plugin policy, not an agent.md option. A developer who needs it must implement a reviewed local plugin around this package's TypeScript API.

Assembly Line writes /workspace/.assembly-line/credentials/mirror/config.json with mode 0600. Set MIRROR_HOME=/workspace/.assembly-line/credentials/mirror for Mirror CLI commands. The reserved directory is excluded from workspace versions. Only the current access token is projected; the rotating refresh token stays in the host-side grant store.