Linear Incident Runbook

Linear Incident Runbook

Overview

Step-by-step runbooks for handling production incidents with Linear integrations. Covers API authentication failures, rate limiting, webhook issues, and Linear platform outages.

Incident Classification

Immediate Actions (All Incidents)

Step 1: Confirm the Issue

set -euo pipefail

# 1. Check Linear platform status
curl -s https://status.linear.app/api/v2/status.json | jq '.status'

# 2. Test your API key
curl -s -X POST https://api.linear.app/graphql \
  -H "Authorization: $LINEAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "{ viewer { name email } }"}' | jq .

# 3. Check rate limit status
curl -s -I -X POST https://api.linear.app/graphql \
  -H "Authorization: $LINEAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "{ viewer { id } }"}' 2>&1 | grep -i ratelimit

# 4. Check your app health endpoint
curl -s https://yourapp.com/health/linear | jq .

Step 2: Gather Diagnostic Info

// scripts/incident-diagnostic.ts
import { LinearClient } from "@linear/sdk";

async function diagnose() {
  console.log("=== Linear Incident Diagnostic ===\n");

  // 1. Auth check
  console.log("1. Authentication:");
  try {
    const client = new LinearClient({ apiKey: process.env.LINEAR_API_KEY! });
    const viewer = await client.viewer;
    console.log(`   OK: ${viewer.name} (${viewer.email})`);
  } catch (error: any) {
    console.log(`   FAILED: ${error.message}`);
  }

  // 2. Team access
  console.log("\n2. Team Access:");
  try {
    const client = new LinearClient({ apiKey: process.env.LINEAR_API_KEY! });
    const teams = await client.teams();
    console.log(`   OK: ${teams.nodes.length} teams accessible`);
    teams.nodes.forEach(t => console.log(`     ${t.key}: ${t.name}`));
  } catch (error: any) {
    console.log(`   FAILED: ${error.message}`);
  }

  // 3. Write test
  console.log("\n3. Write Capability:");
  try {
    const client = new LinearClient({ apiKey: process.env.LINEAR_API_KEY! });
    const teams = await client.teams();
    const result = await client.createIssue({
      teamId: teams.nodes[0].id,
      title: "[INCIDENT-DIAG] Safe to delete",
    });
    if (result.success) {
      const issue = await result.issue;
      await issue?.delete();
      console.log("   OK: Created and deleted test issue");
    }
  } catch (error: any) {
    console.log(`   FAILED: ${error.message}`);
  }

  // 4. Rate limit check
  console.log("\n4. Rate Limits:");
  try {
    const resp = await fetch("https://api.linear.app/graphql", {
      method: "POST",
      headers: {
        Authorization: process.env.LINEAR_API_KEY!,
        "Content-Type": "application/json",
      },
      body: JSON.stringify({ query: "{ viewer { id } }" }),
    });
    const remaining = resp.headers.get("x-ratelimit-requests-remaining");
    const limit = resp.headers.get("x-ratelimit-requests-limit");
    console.log(`   Requests: ${remaining}/${limit}`);
  } catch (error: any) {
    console.log(`   FAILED: ${error.message}`);
  }

  console.log("\n=== End Diagnostic ===");
}

diagnose();

Runbook: API Authentication Failure

Symptoms: All API calls returning 401/403, "Authentication required" errors

Diagnosis:

set -euo pipefail
# Verify API key format
echo $LINEAR_API_KEY | head -c 8
# Should output: lin_api_

# Test directly
curl -s -X POST https://api.linear.app/graphql \
  -H "Authorization: $LINEAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "{ viewer { id } }"}' | jq .errors

Resolution:

1. Verify key is loaded: [ -n "$LINEAR_API_KEY" ] && echo "Set" || echo "NOT set"
2. Check if rotated: Linear Settings > Account > API > Personal API keys
3. Generate new key if needed, update secret manager
4. Restart affected services
5. If recent deploy caused it: git revert HEAD && npm run deploy

Runbook: Rate Limiting (HTTP 429)

Symptoms: HTTP 429 responses, "Rate limit exceeded", degraded performance

Diagnosis:

set -euo pipefail
curl -s -I -X POST https://api.linear.app/graphql \
  -H "Authorization: $LINEAR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "{ viewer { id } }"}' 2>&1 | grep -i ratelimit

Resolution:

1. Emergency throttle -- add 5s delay between all requests:

   const EMERGENCY_DELAY_MS = 5000;
   async function emergencyThrottle<T>(fn: () => Promise<T>): Promise<T> {
     await new Promise(r => setTimeout(r, EMERGENCY_DELAY_MS));
     return fn();
   }
   

2. Stop non-critical background jobs (polling, sync)

3. Disable bulk operations

4. Wait for bucket refill (Linear uses leaky bucket, refills continuously)

5. Post-incident: implement proper request queue and caching

Runbook: Webhook Failures

Symptoms: Events not received, signature validation errors, processing timeouts

Diagnosis:

set -euo pipefail
# Check endpoint is reachable
curl -s -o /dev/null -w "%{http_code}" https://yourapp.com/webhooks/linear

# Verify secret length
echo -n "$LINEAR_WEBHOOK_SECRET" | wc -c
# Should be > 20 characters

Resolution:

1. Endpoint unreachable: Check DNS, SSL cert, firewall, load balancer health
2. Signature mismatch: Verify LINEAR_WEBHOOK_SECRET matches webhook config in Linear Settings > API > Webhooks
3. Body parsing issue: Ensure using express.raw() not express.json()
4. Processing timeout: Respond 200 immediately, process async
5. Recreate webhook: Linear Settings > API > Webhooks > delete + recreate

Runbook: Linear Platform Outage

Symptoms: All API calls failing, status.linear.app reports issues

Resolution:

1. Confirm at https://status.linear.app
2. Enable graceful degradation in your app
3. Queue write operations for replay when API recovers
4. Serve cached data for read operations
5. Monitor status page for resolution
6. After recovery: run consistency check to detect missed webhook events

Communication Templates

Initial Announcement

INCIDENT: Linear Integration Issue
Severity: SEVX
Status: Investigating
Impact: [description]
Start: [UTC timestamp]

Investigating issues with Linear integration. Updates to follow.

Resolution

RESOLVED: Linear Integration Issue
Duration: X hours Y minutes
Root Cause: [brief]
Impact: [what was affected]

Post-mortem within 48 hours.

Post-Incident Checklist

[ ] All systems verified healthy
[ ] Stuck/queued jobs cleared
[ ] Data consistency validated
[ ] Stakeholders notified of resolution
[ ] Timeline documented
[ ] Root cause identified
[ ] Action items assigned
[ ] Monitoring gaps addressed

Error Handling

Resources

• Linear Status Page
• Linear API Documentation
• Rate Limiting