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Open SWE Agent: Revolutionizing Developer Productivity with Cloud-Native Automation

高效码农

Understanding Open SWE: A Friendly Guide to the Cloud-Native, Open-Source Coding Agent That Writes Pull Requests While You Sleep

Imagine hiring an experienced engineer who never sleeps, reads your entire codebase in minutes, drafts a detailed plan, and opens a ready-to-merge pull request—all before your morning coffee.
That engineer is called Open SWE, and this guide will walk you through everything you need to know.

1. What Exactly Is Open SWE?

Open SWE is an open-source, asynchronous, cloud-native coding agent.
Built on the LangGraph framework, it can:

  • Understand a repository from scratch
  • Plan a solution for any task you describe
  • Execute code changes across the whole codebase
  • Open a pull request that automatically closes the related issue

Think of it as three specialists rolled into one:

Role Nickname What It Does
Planner The Architect Reads code, splits work into steps, presents a plan for your approval
Programmer The Coder Writes and tests code, fixes bugs, follows the plan line by line
Manager The Coordinator Keeps Planner and Programmer in sync, listens to your feedback in real time

2. Why “Asynchronous” Matters

Traditional scripts run on your laptop:

  • They hog CPU
  • They fail if you close the lid
  • They block you from starting another task

Open SWE runs inside a cloud sandbox:

  • Parallel by design — start as many tasks as you like
  • Resilient — your Wi-Fi can drop; the job keeps running
  • Hands-off — you only intervene when the plan is ready or the PR needs review

3. Two Ways to Talk to Open SWE

Entry Point Best For How It Works
Web UI Visual learners, quick demos Visit https://swe.langchain.com, create a task, watch progress in real time
GitHub Labels Developers living in Issues Add the label open-swe to any issue; the agent replies with a plan you can accept or edit

Pro tip: Add the suffix -auto (e.g., open-swe-auto) to skip human approval for trivial tasks like typo fixes.

4. Getting Started Locally in 15 Minutes

The following commands are copied verbatim from the official repository instructions.

Prerequisites

  • Node.js 18 or newer
  • Yarn 3.5.1 (configured in .yarnrc.yml; do not use npm)

Step-by-Step

# 1. Clone the repository
git clone <repository-url>
cd open-swe

# 2. Install all workspace dependencies
yarn install

# 3. Build every package in the correct order
yarn build        # shared → open-swe → web

After the first build, Turbo will only rebuild what changed, so future iterations are lightning-fast.

5. Repository Layout at a Glance

open-swe/
├── apps/open-swe          # LangGraph agent source
│   ├── src/graphs         # planner, programmer, manager
│   └── langgraph.json     # graph definitions
├── apps/web               # Next.js 15 front-end
│   └── src/components     # Shadcn UI components
├── packages/shared        # Common utilities
│   ├── crypto.ts
│   └── open-swe/types.ts
├── turbo.json             # build orchestration
└── .yarnrc.yml            # Yarn 3.5.1 settings

Golden Rule

Whenever you need a new utility, search in packages/shared/src first—duplication is discouraged.

6. Development Rules Cheat-Sheet

Rule One-Line Reminder
Use Yarn only npm install will throw an error
Run commands from root yarn lint, yarn format, etc.
No console.log Use createLogger('module-name')
Build shared first yarn build handles order automatically
Pre-commit checks yarn lint:fix && yarn format

7. Testing Strategy

Types of Tests

Type File Pattern Purpose
Unit *.test.ts Fast feedback on individual functions
Integration *.int.test.ts End-to-end agent workflows
Single file Any yarn test:single <file>

Commands

yarn test          # all unit tests
yarn test:int      # open-swe integration tests only

Integration tests run inside the cloud sandbox and have a 20-second timeout per test—perfect for catching real-world issues.

8. Your First Real Task: A Walk-Through

Scenario: Add a “Sign In” Button to a React App

Option A — Web UI

  1. Visit https://swe.langchain.com
  2. Click New Task
  3. Describe: “Add a green ‘Sign In’ button to the top-right corner of the landing page”
  4. Wait for the Planner to propose tasks (≈ 1 minute)
  5. Click Approve or edit the plan inline
  6. Watch Programmer write the code, run tests, push commits
  7. Receive a pull request that says “Closes #123”

Option B — GitHub Label

  1. Open a new issue with the same description
  2. Add label open-swe
  3. The Planner posts a comment with the plan
  4. Reply LGTM (Looks Good To Me)
  5. The Programmer force-pushes a branch and opens the PR

9. GitHub Label “Dialects” Explained

Label Human Approval LLM Model Typical Use Case
open-swe Required Default New features
open-swe-auto Skipped Default Typos, simple refactors
open-swe-max Required Claude Opus 4.1 Complex architecture
open-swe-max-auto Skipped Claude Opus 4.1 Massive refactor or upgrade

10. Frequently Asked Questions

Q1: Can I use my own LLM API key?

Yes. In the Web UI, open **Settings** and paste your OpenAI or Anthropic key.
Keys are used only inside your sandbox; they are never sent to external services.

Q2: Does the sandbox support private npm packages?

Yes. Commit an `.npmrc` or `.yarnrc.yml` file at the repository root with your registry token.
The build step injects the token into the container.

Q3: What if the task fails?

1. Open the task log in the Web UI or GitHub comment.
2. Type *“Retry step 3”* in the chat.
3. If it’s an environment issue (e.g., Node version), say *“Upgrade Node to 20”*.

Q4: How do I connect the local front-end to a local agent?

1. Terminal 1: `cd apps/open-swe && yarn dev` (port 8000)
2. Terminal 2: `cd apps/web && yarn dev` (port 3000)
3. The Next.js dev server proxies `/api` requests to port 8000 automatically.

11. Automating Weekly Chores: A One-Line CI Job

Many teams automate dependency bumps.
Add this snippet to .github/workflows/weekly-deps.yml:

- name: Trigger Open SWE
  run: |
    gh issue create \
      --title "Weekly dependency bump" \
      --body "Bump all minor versions, run tests, open PR." \
      --label "open-swe-auto"

Every Monday, the agent wakes up, updates packages, runs the test suite, and opens a pull request without human intervention.

12. Roadmap: Where to Go Next

Your Current Step Recommended Next Move
Just heard of Open SWE Open the live demo and create a “Hello, World!” task
Finished the demo Add your private repository to the GitHub App and tackle a real issue
Ready to contribute Read interface contracts in packages/shared, write tests, run yarn test:int before opening a PR

13. Final Thoughts

Open SWE isn’t here to replace engineers.
It’s here to free you from repetitive chores—dependency updates, boilerplate tests, typo hunts—so you can focus on the creative, high-impact work that only humans can do.

Happy automating!

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