Background Agents: Open-Inspect

An open-source background agents coding system inspired by Ramp's Inspect.

Overview

Open-Inspect provides a hosted background coding agent that can:

• Work on tasks in the background while you focus on other things
• Access full development environments with all tools engineers have
• Support multiple clients (web, Slack, Chrome extension)
• Enable multiplayer sessions where multiple people can collaborate
• Create PRs with proper commit attribution
• Use your choice of AI model — Anthropic Claude or OpenAI Codex via your ChatGPT subscription

Security Model (Single-Tenant Only)

Important: This system is designed for single-tenant deployment only, where all users are trusted members of the same organization with access to the same repositories.

How It Works

The system uses a shared GitHub App installation for all git operations (clone, push). This means:

• All users share the same GitHub App credentials - The GitHub App must be installed on your organization's repositories, and any user of the system can access any repo the App has access to
• No per-user repository access validation - The system does not verify that a user has permission to access a specific repository before creating a session
• User OAuth tokens are used for PR creation - PRs are created using the user's GitHub OAuth token, ensuring proper attribution and that users can only create PRs on repos they have write access to

Token Architecture

Token Type	Purpose	Scope
GitHub App Token	Clone repos, push code	All repos where App is installed
User OAuth Token	Create PRs, user info	Repos user has access to
WebSocket Token	Real-time session auth	Single session

Why Single-Tenant Only

This architecture follows Ramp's Inspect design, which was built for internal use where all employees are trusted and have access to company repositories.

For multi-tenant deployment, you would need:

• Per-tenant GitHub App installations
• Access validation at session creation
• Tenant isolation in the data model

Deployment Recommendations

1. Deploy behind your organization's SSO/VPN - Ensure only authorized employees can access the web interface
2. Install GitHub App only on intended repositories - The App's installation scope defines what the system can access
3. Use GitHub's repository selection - When installing the App, select specific repositories rather than "All repositories"

Architecture

                                    ┌──────────────────┐
                                    │     Clients      │
                                    │ ┌──────────────┐ │
                                    │ │     Web      │ │
                                    │ │    Slack     │ │
                                    │ │   Extension  │ │
                                    │ └──────────────┘ │
                                    └────────┬─────────┘
                                             │
                                             ▼
┌────────────────────────────────────────────────────────────────────┐
│                     Control Plane (Cloudflare)                      │
│  ┌──────────────────────────────────────────────────────────────┐  │
│  │                   Durable Objects (per session)               │  │
│  │  ┌─────────┐  ┌─────────┐  ┌─────────┐  ┌───────────────┐   │  │
│  │  │ SQLite  │  │WebSocket│  │  Event  │  │   GitHub      │   │  │
│  │  │   DB    │  │   Hub   │  │ Stream  │  │ Integration   │   │  │
│  │  └─────────┘  └─────────┘  └─────────┘  └───────────────┘   │  │
│  └──────────────────────────────────────────────────────────────┘  │
│  ┌──────────────────────────────────────────────────────────────┐  │
│  │              D1 Database (repo-scoped secrets)                │  │
│  └──────────────────────────────────────────────────────────────┘  │
└────────────────────────────────┬───────────────────────────────────┘
                                 │
                                 ▼
┌────────────────────────────────────────────────────────────────────┐
│                      Data Plane (Modal)                             │
│  ┌──────────────────────────────────────────────────────────────┐  │
│  │                     Session Sandbox                           │  │
│  │  ┌───────────┐  ┌───────────┐  ┌───────────┐                 │  │
│  │  │ Supervisor│──│  OpenCode │──│   Bridge  │─────────────────┼──┼──▶ Control Plane
│  │  └───────────┘  └───────────┘  └───────────┘                 │  │
│  │                      │                                        │  │
│  │              Full Dev Environment                             │  │
│  │        (Node.js, Python, git, Playwright)                     │  │
│  └──────────────────────────────────────────────────────────────┘  │
└────────────────────────────────────────────────────────────────────┘

Packages

Package	Description
modal-infra	Modal sandbox infrastructure
control-plane	Cloudflare Workers + Durable Objects
web	Next.js web client
shared	Shared types and utilities

Getting Started

For a practical setup guide (local + contributor + deployment paths), start with docs/SETUP_GUIDE.md.

See docs/GETTING_STARTED.md for deployment instructions.

To understand the architecture and core concepts, read docs/HOW_IT_WORKS.md.

Key Features

Fast Startup

Sessions start near-instantly using Modal filesystem snapshots:

• Images rebuilt every 30 minutes with latest code
• Dependencies pre-installed and cached
• Sandboxes warmed proactively when user starts typing

Multiplayer Sessions

Multiple users can collaborate in the same session:

• Presence indicators show who's active
• Prompts are attributed to their authors in git commits
• Real-time streaming to all connected clients

Commit Attribution

Commits are attributed to the user who sent the prompt:

// Configure git identity per prompt
await configureGitIdentity({
  name: author.scmName,
  email: author.scmEmail,
});

Multi-Provider Model Support

Choose the AI model that fits your task — Anthropic Claude or OpenAI Codex:

Provider	Models
Anthropic	Claude Haiku, Sonnet, Opus
OpenAI	GPT 5.2, GPT 5.2 Codex, GPT 5.3 Codex

OpenAI models work with your existing ChatGPT subscription — no separate API key needed. See docs/OPENAI_MODELS.md for setup instructions.

Repository Lifecycle Scripts

Repositories can define two optional startup scripts under .openinspect/:

# .openinspect/setup.sh (provisioning)
#!/bin/bash
npm install
pip install -r requirements.txt

# .openinspect/start.sh (runtime startup)
#!/bin/bash
docker compose up -d postgres redis

• setup.sh runs for image builds and fresh sessions
• setup.sh is skipped for repo-image and snapshot-restore starts
• setup.sh failures are non-fatal for fresh sessions, but fatal in image build mode
• start.sh runs for every non-build session startup (fresh, repo-image, snapshot-restore)
• start.sh failures are strict: if present and it fails, session startup fails
• Default timeouts:
  • SETUP_TIMEOUT_SECONDS (default 300)
  • START_TIMEOUT_SECONDS (default 120)
• Both hooks receive OPENINSPECT_BOOT_MODE (build, fresh, repo_image, snapshot_restore)

License

MIT

Credits

Inspired by Ramp's Inspect and built with:

• Modal - Cloud sandbox infrastructure
• Cloudflare Workers - Edge computing
• OpenCode - Coding agent runtime
• Next.js - Web framework