Linear

Agent Swarm integrates with Linear as an inbound issue-tracker source: assigning the agent to a Linear issue creates a swarm task and a Linear AgentSession. Activity flows back into the AgentSession as thought / action / response / error events.

What it does

• Inbound on assignment. When a user assigns the Linear agent integration to an issue, Linear fires an AgentSession webhook. The handler creates a swarm task linked to the session.
• State-gated task creation. Only issues whose WorkflowState.type is in the configured allowlist trigger a task. By default that's unstarted, started, completed, canceled — i.e. everything except triage and backlog. Skipped assignments leave a comment on the AgentSession explaining how to retry.
• Label override. A label on the issue (default swarm-ready, configurable) bypasses the state gate so users can pre-stage backlog issues to auto-trigger when assigned.
• AgentSession activity stream. The agent posts thoughts, actions, responses, and errors back to the AgentSession in real time. A response activity auto-completes the session.
• Webhook signing + dedup. Inbound webhooks are HMAC-SHA256 verified and deduped by the Linear-Delivery header (5-minute TTL).
• Dashboard linking. externalUrls on each session link to the swarm dashboard's task page.

Setup

1. Create a Linear OAuth App

1. Go to Linear → Settings → API → Applications and create a new application:
   • Actor: Application
   • Callback URL: <MCP_BASE_URL>/api/trackers/linear/callback
   • Webhook URL: <MCP_BASE_URL>/api/trackers/linear/webhook
2. Enable Agent session events in the webhook settings.
3. Copy the Client ID, Client Secret, and Webhook Signing Secret.

2. Configure environment

Add to your .env:

# Required — OAuth + webhook auth
LINEAR_CLIENT_ID=your-client-id
LINEAR_CLIENT_SECRET=your-client-secret
LINEAR_REDIRECT_URI=http://localhost:3013/api/trackers/linear/callback
LINEAR_SIGNING_SECRET=your-webhook-signing-secret

# Optional — gate config (defaults shown)
LINEAR_ALLOWED_STATES=unstarted,started,completed,canceled
LINEAR_SWARM_READY_LABEL=swarm-ready

# Optional — disable the integration entirely
# LINEAR_DISABLE=true

With portless dev mode (bun run dev:http):

LINEAR_REDIRECT_URI=https://api.swarm.localhost:1355/api/trackers/linear/callback

3. Complete OAuth

Start the server and visit <MCP_BASE_URL>/api/trackers/linear/authorize in a browser to complete the OAuth flow. The token is encrypted at rest in swarm_config.

How it works

Inbound flow

State gate

When an issue is assigned, the handler resolves the issue's WorkflowState.type and label list. The decision is:

LINEAR_ALLOWED_STATES is a comma-separated list of Linear WorkflowState.type values. The full enum is triage, backlog, unstarted, started, completed, canceled. Whitespace and case are normalized.

Examples:

# Default: skip Backlog and Triage
LINEAR_ALLOWED_STATES=unstarted,started,completed,canceled

# Only trigger when actively in progress
LINEAR_ALLOWED_STATES=started

# Open the gate completely (skip everything → only label override works)
LINEAR_ALLOWED_STATES=

The Linear AgentSessionEvent payload doesn't include state or labels, so the handler issues a small GraphQL query (issue.state.type + labels.nodes.name) to resolve them. If the OAuth token is missing, the gate fails open.

Skip message

When the gate skips an assignment, the agent posts a response activity to the AgentSession (which auto-completes it):

Agent Swarm received the assignment but skipped — this issue is in Backlog.

To trigger work, move it to an allowed workflow state (e.g. Todo or In Progress), or add the swarm-ready label and re-assign the agent.

This is a deliberate design choice: silent no-ops on assignments are confusing. Always leave a trace.

Issue updates

Linear Issue updates that target a tracked issue refresh the swarm task's tracker metadata. State transitions:

Follow-up messages

When a user sends a message in the Linear agent chat after the original task is done:

1. Linear fires a prompted AgentSessionEvent.
2. The handler creates a new swarm task with the follow-up context, repointing the existing tracker_sync to it.
3. The agent processes the follow-up via the normal task lifecycle.

If the original task is still in flight, the handler posts a thought activity acknowledging the message but does not create a new task — the message is folded into the existing run.

Stop signal

If the user clicks the stop button in Linear, the agent activity carries signal: "stop". The handler cancels the active swarm task and ends the session with a "Task cancelled by user." response.

Outbound updates

The webhook integration is one-way. To push updates back to Linear from the swarm — creating issues, transitioning states, posting comments outside an AgentSession — use the linear-interaction skill. The skill wraps the Linear GraphQL API:

mutation IssueCreate($input: IssueCreateInput!) {
  issueCreate(input: $input) { issue { id identifier } }
}

mutation IssueUpdate($id: String!, $input: IssueUpdateInput!) {
  issueUpdate(id: $id, input: $input) { success }
}

mutation CommentCreate($input: CommentCreateInput!) {
  commentCreate(input: $input) { comment { id } }
}

Authentication uses the swarm's OAuth token from swarm_config (stored encrypted under LINEAR_OAUTH_TOKEN). The lead agent fetches it via db-query; worker agents request it from the lead.

For activity within an existing AgentSession (the agent's running task), use the helpers in src/linear/sync.ts — postAgentSessionResponse, postAgentSessionThought, postAgentSessionAction, postAgentSessionError. These don't need the skill; they're called directly from the worker session.

MCP tools

Architecture

The integration sits on top of a generic tracker abstraction shared with Jira and (eventually) others:

• src/oauth/ — Reusable OAuth module with oauth_apps / oauth_tokens tables and PKCE support.
• src/be/db-queries/tracker.ts — Generic tracker_sync and tracker_agent_mapping tables.
• src/linear/ — Linear-specific webhook handler (webhook.ts), AgentSession sync (sync.ts), state gate (gate.ts), and prompt templates (templates.ts).

The state gate is exposed as a pure function (shouldCreateTaskFromLinearEvent in src/linear/gate.ts) so it can be unit-tested without spinning up the API.

Related skills & references

• linear-interaction skill — canonical procedure for pushing outbound updates (create issues, change status, comment) via the Linear GraphQL API. Invoke with the Skill tool.
• Linear API docs — GraphQL schema and authentication reference.
• @linear/sdk — official TypeScript SDK; the swarm uses raw fetch against the GraphQL endpoint, but the SDK's type definitions are the canonical reference for payload shapes.

Related docs

• Environment Variables — full env reference
• Task Lifecycle — how tasks created from Linear flow through the swarm
• Architecture Overview — system architecture including integrations