Linear Verified Webhook Processing

Overview

Build an ingress path that proves authenticity on raw bytes, acknowledges quickly, and makes downstream processing replay-safe.

Prerequisites

The target repository, Linear workspace, environment, and accountable owner
Current security, privacy, compliance, capacity, and change-control requirements
An approved Linear credential only when a bounded live verification is necessary

Tool Discipline

Use Read, Glob, and Grep to inspect code, configuration, and evidence. Use WebFetch only for current first-party Linear documentation and package metadata. Use Write or Edit only for requested implementation with known target files. Never write credentials, customer content, unrestricted environment output, or unredacted GraphQL variables.

Current Contract

The endpoint must be public HTTPS and return HTTP 200 within five seconds; failures retry after one minute, one hour, and six hours, up to three retries.
Linear-Signature is the hex HMAC-SHA256 of the exact raw body; Linear-Delivery is the unique delivery UUID and Linear-Timestamp is epoch milliseconds.
Only workspace admins or OAuth applications with admin scope can create or read webhooks.
The official SDK provides LinearWebhookClient, including raw-body signature verification and framework handlers.

Authentication

Use a personal API key only for owner-controlled scripts, OAuth with PKCE for user-delegated applications, or an enabled client-credentials grant for approved automation. Personal keys use Authorization: <API_KEY>; OAuth tokens use Authorization: Bearer <ACCESS_TOKEN>. Store credentials server-side in an approved secret manager.

Treat app approval, team access, scope changes, credential creation, rotation, revocation, and production access as owner-approved actions.

Instructions

Select explicit resource types and team/all-public-team scope, and identify the webhook/admin owner.
Capture the exact raw request bytes before JSON middleware and verify HMAC-SHA256 with the configured signing secret.
Reject invalid or stale/replayed requests, deduplicate by Linear-Delivery, enqueue the verified envelope, and return 200 within five seconds.
Process events idempotently using action, type, entity ID, updatedFrom, organization, and webhook ID as appropriate.
Bound retries and dead-letter handling; never assume Linear will retry beyond the documented schedule.
Run periodic cursor-based reconciliation and test create/update/remove, duplicate, delayed, revoked-app, and secret-rotation cases.

Approval Boundaries

Do not create, reveal, rotate, or revoke credentials; authorize an OAuth app; change scopes or team access; create, mutate, archive, or delete workspace data; configure or re-enable webhooks; import or export data; change roles, SCIM, or audit streaming; transmit diagnostics; change paid entitlements; or perform another production mutation without explicit approval from the accountable owner. Keep diagnosis read-only unless implementation was requested.

Output

Return the workspace and team scope, auth mode without credential value, files and contracts inspected, exact operation names, evidence collected, validation result, sensitive fields redacted, remaining risk, accountable owner, approval state, and rollback or next action.

Error Handling

Condition	Response
Signature mismatch	Return non-200, do not parse into business logic, and verify raw-body/secret selection.
Processing exceeds five seconds	Queue after verification and acknowledge before doing business work.
Duplicate delivery	Return 200 after recording the dedupe hit; do not repeat side effects.
Webhook disabled	Repair the endpoint, manually re-enable after approval, then reconcile the missed interval.

Examples

Use a compact handoff that makes scope, mutation authority, and verification evidence reviewable.

Input:

scope=team; events=Issue,Comment; raw-body=true; queue=durable

Expected handoff:

signature=verified; ack<5s; dedupe=delivery-id; reconciliation=enabled

linear-webhooks-events