* feat(reviewer): inline AGENTS.md into reviewer system prompt Fetches AGENTS.md from the PR's head_sha via the GitHub contents API during reviewer setup and inlines it as a "Repository conventions" block in the system prompt. Mirrors how the per-repo review style prompt is already wired. The main agent has long had a mandatory step to read AGENTS.md after cloning, but the reviewer often skips cloning entirely (it can `gh pr diff` directly), so it never saw the file. Loading it deterministically means the reviewer judges findings against the project's own conventions instead of relying on the model to fetch the file itself. * fix(reviewer): fetch AGENTS.md from base_sha, not head_sha The reviewer inlines AGENTS.md into its system prompt. Reading from head_sha means a PR author can edit AGENTS.md in the same PR being reviewed and smuggle instructions like "ignore all bugs" / "publish no findings" into the reviewer's prompt. Switch to base_sha (the target branch's pre-PR state, which is trusted) and update the prompt text to reflect that the contents come from the base, not the head. --------- Co-authored-by: open-swe[bot] <open-swe@users.noreply.github.com> |
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| ui | ||
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| AGENTS.md | ||
| CLAUDE.md | ||
| CUSTOMIZATION.md | ||
| default_prompt.md | ||
| Dockerfile | ||
| INSTALLATION.md | ||
| langgraph.json | ||
| LICENSE | ||
| Makefile | ||
| pyproject.toml | ||
| README.md | ||
| REVIEWER_DESIGN.md | ||
| SECURITY.md | ||
| uv.lock | ||
Open-source framework for building your org's internal coding agent.
Elite engineering orgs like Stripe, Ramp, and Coinbase are building their own internal coding agents — Slackbots, CLIs, and web apps that meet engineers where they already work. These agents are connected to internal systems with the right context, permissioning, and safety boundaries to operate with minimal human oversight.
Open SWE is the open-source version of this pattern. Built on LangGraph and Deep Agents, it gives you the same architecture those companies built internally: cloud sandboxes, Slack and Linear invocation, subagent orchestration, and automatic PR creation — ready to customize for your own codebase and workflows.
Note
💬 Read the announcement blog post here
Architecture
Open SWE makes the same core architectural decisions as the best internal coding agents. Here's how it maps to the patterns described in this overview of Stripe's Minions, Ramp's Inspect, and Coinbase's Cloudbot:
1. Agent Harness — Composed on Deep Agents
Rather than forking an existing agent or building from scratch, Open SWE composes on the Deep Agents framework — similar to how Ramp built on top of OpenCode. This gives you an upgrade path (pull in upstream improvements) while letting you customize the orchestration, tools, and middleware for your org.
create_deep_agent(
model="openai:gpt-5.5",
system_prompt=construct_system_prompt(...),
tools=[http_request, fetch_url, linear_comment, slack_thread_reply],
backend=sandbox_backend,
middleware=[ToolErrorMiddleware(), check_message_queue_before_model, ...],
)
2. Sandbox — Isolated Cloud Environments
Every task runs in its own isolated cloud sandbox — a remote Linux environment with full shell access. The repo is cloned in, the agent gets full permissions, and the blast radius of any mistake is fully contained. No production access, no confirmation prompts.
Open SWE supports multiple sandbox providers out of the box — Modal, Daytona, Runloop, and LangSmith — and you can plug in your own. See the Customization Guide for details.
This follows the principle all three companies converge on: isolate first, then give full permissions inside the boundary.
- Each thread gets a persistent sandbox (reused across follow-up messages)
- Sandboxes auto-recreate if they become unreachable
- Multiple tasks run in parallel — each in its own sandbox, no queuing
3. Tools — Curated, Not Accumulated
Stripe's key insight: tool curation matters more than tool quantity. Open SWE follows this principle with a small, focused toolset:
| Tool | Purpose |
|---|---|
execute |
Shell commands in the sandbox |
fetch_url |
Fetch web pages as markdown |
http_request |
API calls (GET, POST, etc.) |
linear_comment |
Post updates to Linear tickets |
slack_thread_reply |
Reply in Slack threads |
GitHub operations are performed with GH_TOKEN=dummy gh inside the sandbox, backed by the LangSmith proxy. Plus the built-in Deep Agents tools: read_file, write_file, edit_file, ls, glob, grep, write_todos, and task (subagent spawning).
4. Context Engineering — AGENTS.md + Source Context
Open SWE gathers context from two sources:
AGENTS.md— If the repo contains anAGENTS.mdfile at the root, it's read from the sandbox and injected into the system prompt. This is your repo-level equivalent of Stripe's rule files: encoding conventions, testing requirements, and architectural decisions that every agent run should follow.- Source context — The full Linear issue (title, description, comments) or Slack thread history is assembled and passed to the agent, so it starts with rich context rather than discovering everything through tool calls.
5. Orchestration — Subagents + Middleware
Open SWE's orchestration has two layers:
Subagents: The Deep Agents framework natively supports spawning child agents via the task tool. The main agent can fan out independent subtasks to isolated subagents — each with its own middleware stack, todo list, and file operations. This is similar to Ramp's child sessions for parallel work.
Middleware: Deterministic middleware hooks run around the agent loop:
check_message_queue_before_model— Injects follow-up messages (Linear comments or Slack messages that arrive mid-run) before the next model call. You can message the agent while it's working and it'll pick up your input at its next step.notify_step_limit_reached— After-agent hook that posts a Slack reply when the agent hits the model-call limit, so users get a clear signal instead of silence.ToolErrorMiddleware— Catches and handles tool errors gracefully.
6. Invocation — Slack, Linear, and GitHub
All three companies in the article converge on Slack as the primary invocation surface. Open SWE does the same:
- Slack — Mention the bot in any thread. Supports
repo:owner/namesyntax to specify which repo to work on. The agent replies in-thread with status updates and PR links. - Linear — Comment
@opensweon any issue. The agent reads the full issue context, reacts with 👀 to acknowledge, and posts results back as comments. - GitHub — Tag
@openswein PR comments on agent-created PRs to have it address review feedback and push fixes to the same branch.
Each invocation creates a deterministic thread ID, so follow-up messages on the same issue or thread route to the same running agent.
7. Validation — Prompt-Driven
The agent is instructed to run linters, formatters, and tests before committing, and is responsible end-to-end for committing, pushing, opening/updating the draft PR, and replying in the source channel. This is an area where you can extend Open SWE for your org: add deterministic CI checks, visual verification, or review gates as additional middleware. See the Customization Guide for how.
Comparison
| Decision | Open SWE | Stripe (Minions) | Ramp (Inspect) | Coinbase (Cloudbot) |
|---|---|---|---|---|
| Harness | Composed (Deep Agents/LangGraph) | Forked (Goose) | Composed (OpenCode) | Built from scratch |
| Sandbox | Pluggable (Modal, Daytona, Runloop, etc.) | AWS EC2 devboxes (pre-warmed) | Modal containers (pre-warmed) | In-house |
| Tools | ~15, curated | ~500, curated per-agent | OpenCode SDK + extensions | MCPs + custom Skills |
| Context | AGENTS.md + issue/thread | Rule files + pre-hydration | OpenCode built-in | Linear-first + MCPs |
| Orchestration | Subagents + middleware | Blueprints (deterministic + agentic) | Sessions + child sessions | Three modes |
| Invocation | Slack, Linear, GitHub | Slack + embedded buttons | Slack + web + Chrome extension | Slack-native |
| Validation | Prompt-driven | 3-layer (local + CI + 1 retry) | Visual DOM verification | Agent councils + auto-merge |
Features
- Trigger from Linear, Slack, or GitHub — mention
@openswein a comment to kick off a task - Instant acknowledgement — reacts with 👀 the moment it picks up your message
- Message it while it's running — send follow-up messages mid-task and it'll pick them up before its next step
- Run multiple tasks in parallel — each task runs in its own isolated cloud sandbox
- GitHub OAuth built-in — authenticates with your GitHub account automatically
- Opens PRs automatically — commits changes and opens a draft PR when done, linked back to your ticket
- Subagent support — the agent can spawn child agents for parallel subtasks
Getting Started
- Installation Guide — GitHub App creation, LangSmith, Linear/Slack/GitHub triggers, and production deployment
- Customization Guide — swap the sandbox, model, tools, triggers, system prompt, and middleware for your org
License
MIT