Linear API Skill

You have access to the Linear GraphQL API via the http tool. Credentials are automatically injected — never construct Authorization headers manually. When the URL host is api.linear.app, the system injects Authorization: {linear_api_key} transparently (no Bearer prefix — Linear API keys are sent raw).

Identity bootstrap (first use)

Linear's API key does not tell you who the user IS inside Linear. Before running any "my issues" / "assigned to me" / "my tickets" request, make sure the user's Linear identity is cached. This avoids re-fetching viewer on every request and makes filter-by-assignee queries deterministic.

Cache file

Path: context/intel/linear-identity.md

Shape:

---
type: linear-identity
bootstrapped_at: 2026-04-21
refreshed_at: 2026-04-21
stale_after: 2026-05-21
---
# Linear identity
user_id: 8a7f...-uuid
display_name: Tobias Holenstein
email: tobias@...
timezone: Europe/Zurich

## Teams
- id: team-uuid-a, key: ENG, name: Engineering
- id: team-uuid-b, key: PROD, name: Product

## Default team
ENG

Bootstrap flow

1. memory_read("context/intel/linear-identity.md"). If the file exists and stale_after is in the future, use it and stop.
2. If missing or stale, run one GraphQL call:

   query { viewer { id name displayName email } teams(first: 50) { nodes { id key name } } }

3. Write the cache via memory_write with stale_after = today + 30 days.
4. If the returned team list has exactly one team, record it as Default team. If more than one, ask the user once: "I see teams ENG, PROD, OPS. Which one do you default to for new issues?" and store the answer.
5. On HTTP 401 or an AuthenticationError GraphQL error, invalidate the cache and re-prompt the user to check their API key — do not silently retry.

Using the cached identity

• "list my issues" / "what's assigned to me" → filter by assignee: { id: { eq: "<cached user_id>" } }, not by assignee: { isMe: true } (the isMe filter is not universally available and viewer round-trips are wasteful).
• "create an issue in my team" → use cached Default team id without asking.
• "create an issue in " → match against cached team names; ask only if no match.
• Skills that import external work into Linear must consume this cache rather than re-resolving identity per run.

API Patterns

Linear uses a single GraphQL endpoint: https://api.linear.app/graphql

All requests are POST with a JSON body containing query and optional variables.

List Issues

http(method="POST", url="https://api.linear.app/graphql", body={"query": "{ issues(first: 20, orderBy: updatedAt) { nodes { id identifier title state { name } assignee { name } priority priorityLabel createdAt } } }"})

List Issues Assigned to the User (uses identity cache)

http(method="POST", url="https://api.linear.app/graphql", body={"query": "query($uid: ID!) { issues(filter: { assignee: { id: { eq: $uid } }, state: { type: { nin: [completed, canceled] } } }, first: 50, orderBy: updatedAt) { nodes { id identifier title state { name type } priority priorityLabel url updatedAt } } }", "variables": {"uid": "<cached user_id>"}})

Never pass viewer.id inline from a fresh round-trip when the cache is valid — consult context/intel/linear-identity.md.

Get Issue by Identifier

http(method="POST", url="https://api.linear.app/graphql", body={"query": "query($id: String!) { issue(id: $id) { id identifier title description state { name } assignee { name } labels { nodes { name } } comments { nodes { body user { name } createdAt } } } }", "variables": {"id": "ISSUE_ID"}})

Search Issues

http(method="POST", url="https://api.linear.app/graphql", body={"query": "query($term: String!) { issueSearch(query: $term, first: 10) { nodes { id identifier title state { name } priorityLabel } } }", "variables": {"term": "SEARCH_TERM"}})

Create Issue

http(method="POST", url="https://api.linear.app/graphql", body={"query": "mutation($input: IssueCreateInput!) { issueCreate(input: $input) { success issue { id identifier title url } } }", "variables": {"input": {"title": "...", "description": "...", "teamId": "TEAM_ID", "priority": 2}}})

List Teams (to get teamId for issue creation)

http(method="POST", url="https://api.linear.app/graphql", body={"query": "{ teams { nodes { id name key } } }"})

Update Issue State

http(method="POST", url="https://api.linear.app/graphql", body={"query": "mutation($id: String!, $stateId: String!) { issueUpdate(id: $id, input: { stateId: $stateId }) { success issue { id identifier title state { name } } } }", "variables": {"id": "ISSUE_UUID", "stateId": "STATE_UUID"}})

Response Handling

• Linear returns {"data": {...}} on success, {"errors": [...]} on failure.
• Issue identifiers look like ENG-123 (team key + number).
• Always check for errors in the response before processing data.
• GraphQL errors include a message and optional extensions with error codes.

Common Mistakes

• Do NOT add an Authorization header — it is injected automatically.
• Always use POST method — Linear's API is GraphQL only.
• The id field is a UUID, the identifier field is human-readable (e.g., ENG-42).
• Use issueSearch for text search, not issues with a filter (text search is separate).
• When creating issues, you MUST provide teamId. List teams first if unknown.