linear-local-dev-loop

Linear Local Dev Loop

Overview

Set up an efficient local development workflow for Linear integrations.

Prerequisites

• Node.js 18+ with TypeScript
• Linear SDK installed
• Separate Linear workspace for development (recommended)
• ngrok or similar for webhook testing

Instructions

Step 1: Project Setup

set -euo pipefail
# Initialize project
mkdir linear-integration && cd linear-integration
npm init -y
npm install @linear/sdk typescript ts-node dotenv
npm install -D @types/node vitest

# Create tsconfig.json
npx tsc --init --target ES2022 --module NodeNext --moduleResolution NodeNext

Step 2: Environment Configuration

# Create .env for local development
cat > .env << 'EOF'
LINEAR_API_KEY=lin_api_dev_xxxxxxxxxxxx
LINEAR_WEBHOOK_SECRET=your_webhook_secret
NODE_ENV=development
EOF

# Create .env.example (commit this)
cat > .env.example << 'EOF'
LINEAR_API_KEY=lin_api_xxxxxxxxxxxx
LINEAR_WEBHOOK_SECRET=
NODE_ENV=development
EOF

# Add to .gitignore
echo ".env" >> .gitignore
echo ".env.local" >> .gitignore

Step 3: Create Development Client

// src/client.ts
import { LinearClient } from "@linear/sdk";
import dotenv from "dotenv";

dotenv.config();

export const linearClient = new LinearClient({
  apiKey: process.env.LINEAR_API_KEY!,
});

export async function verifyClient(): Promise<boolean> {
  try {
    const viewer = await linearClient.viewer;
    console.log(`[Linear] Connected as ${viewer.name}`);
    return true;
  } catch (error) {
    console.error("[Linear] Connection failed:", error);
    return false;
  }
}

Step 4: Create Test Utilities

// src/test-utils.ts
import { linearClient } from "./client";

export async function createTestIssue(teamKey: string) {
  const teams = await linearClient.teams();
  const team = teams.nodes.find(t => t.key === teamKey);

  if (!team) throw new Error(`Team ${teamKey} not found`);

  const result = await linearClient.createIssue({
    teamId: team.id,
    title: `[TEST] ${new Date().toISOString()}`,
    description: "Automated test issue - safe to delete",
  });

  return result.issue;
}

export async function cleanupTestIssues(teamKey: string) {
  const issues = await linearClient.issues({
    filter: {
      team: { key: { eq: teamKey } },
      title: { startsWith: "[TEST]" },
    },
  });

  for (const issue of issues.nodes) {
    await issue.delete();
  }

  console.log(`Cleaned up ${issues.nodes.length} test issues`);
}

Step 5: Set Up Watch Mode

// package.json scripts
{
  "scripts": {
    "dev": "ts-node --watch src/index.ts",
    "test": "vitest",
    "test:watch": "vitest --watch",
    "verify": "ts-node src/verify.ts"
  }
}

Output

• Local development environment ready
• Environment variables configured
• Test utilities for creating/cleaning test data
• Watch mode for rapid iteration

Error Handling

Error	Cause	Solution
API key not set	Missing .env file	Copy .env.example to .env
Cannot find module	TypeScript config issue	Check tsconfig.json paths
Connection refused	Network issue	Verify internet connectivity
Webhook not received	Tunnel not running	Start ngrok tunnel

Examples

Webhook Development with ngrok

set -euo pipefail
# Terminal 1: Start your webhook server
npm run dev

# Terminal 2: Start ngrok tunnel
ngrok http 3000  # 3000: 3 seconds in ms

# Copy the https URL and add to Linear webhook settings

Integration Test Example

// tests/integration.test.ts
import { describe, it, expect, afterAll } from "vitest";
import { createTestIssue, cleanupTestIssues } from "../src/test-utils";

describe("Linear Integration", () => {
  const teamKey = "ENG"; // Your test team

  afterAll(async () => {
    await cleanupTestIssues(teamKey);
  });

  it("should create and fetch an issue", async () => {
    const issue = await createTestIssue(teamKey);
    expect(issue).toBeDefined();
    expect(issue?.title).toContain("[TEST]");
  });
});

Resources

• Linear SDK TypeScript
• Webhook Development
• ngrok Documentation

Next Steps

After setting up local dev, proceed to linear-sdk-patterns for best practices.