Open-Source Coding Agent in the terminal

Open-source AI coding agent that spawns parallel agents, each bound to the LLM of your choice.

Website and documentation coming soon!

OpenDev Demo

--- ### Introduction OpenDev is an open-source, terminal-native coding agent built as a compound AI system. Instead of a single monolithic LLM, it uses a structured ensemble of agents and workflows -- each independently bound to a user-configured model. Work is organized into concurrent sessions composed of specialized sub-agents. Each agent executes typed workflows (Execution, Thinking, Compaction) that independently bind to an LLM, enabling fine-grained cost, latency, and capability trade-offs per workflow. OpenDev automatically routes each phase of work to the right model. Five workflow slots — **Normal** (execution), **Thinking** (reasoning), **Compact** (context summarization), **Self-Critique** (output verification), and **VLM** (vision) — each bind independently to any LLM you configure. For example, Claude Opus handles execution, GPT-o3 handles reasoning, and a lightweight Qwen model handles compaction — all routed automatically. Together, these form a compound AI system where multiple models collaborate, each optimized for its role. OpenDev is written in **Rust** — it starts in **4.3 ms**, uses just **9.4 MB of memory**, and ships as a single **18 MB binary**. That makes it the **fastest and lightest coding agent** available today — up to **128x faster startup** and **30x less memory** than alternatives.

| Agent | Startup (mean ± σ) | Peak Memory (median) | Install Size | |-------|--------:|------------:|-------------:| | **OpenDev** 0.1.4 | **4.3 ms ± 0.4 ms** | **9.4 MB** | **18 MB** | | Codex 0.116.0 | 37.8 ms ± 0.8 ms (9x) | 43.7 MB (4.6x) | 116 MB | | Claude Code 2.1.87 | 87.3 ms ± 2.0 ms (20x) | 214.6 MB (22.8x) | 188 MB | | OpenCode 1.2.27 | 557.4 ms ± 31.8 ms (128x) | 285.9 MB (30.4x) | 90 MB | _{macOS ARM64 (Apple Silicon) · Startup: hyperfine --shell=none --warmup 10 --runs 100 · Memory: /usr/bin/time -l median of 20 runs · Multipliers relative to OpenDev}

OpenDev Compound AI Architecture

--- ### Why OpenDev? - **Blazing fast, ultra lightweight.** 4.3 ms startup, 9.4 MB RAM, 18 MB on disk. Written in Rust with zero interpreter overhead — it launches before other agents finish loading their runtime. - **Proactive, not reactive.** OpenDev can plan, execute, and iterate autonomously. Kick off a refactoring, walk away, and come back to a PR ready for review. - **Multi-provider, multi-model.** Assign different models from different providers to every workflow and session, all running in parallel. Your models, your rules. - **TUI + Web UI.** A full terminal UI for power users and a Web UI for visual monitoring. The Web UI supports remote sessions, so you can start a task from your phone and let OpenDev work while you sleep. --- ### ⚡ Agent Fleet — Parallel Execution at Scale

OpenDev Agent Fleet

A fleet of agents, each independently exploring a different crate — all running concurrently in a single session.

Need to survey an entire codebase? Refactor across 20 crates? Run a dozen tool calls at once? **Spawn a fleet.** OpenDev's agent fleet launches multiple sub-agents in parallel, each with its own LLM binding, context window, and tool access. Because the runtime is written in Rust with fully async I/O, there is zero interpreter overhead — agents fan out across your workspace and converge results back in seconds, not minutes. ``` You OpenDev Fleet │ ┌─ Agent 1 → crate/agents │ "survey all crates" ├─ Agent 2 → crate/http │ ─────────────────────► ├─ Agent 3 → crate/tui │ ├─ Agent 4 → crate/tools │ ├─ ... │ ◄── aggregated results └─ Agent N → crate/config ``` - **Concurrent, not sequential.** Every agent runs its own async task — no GIL, no queue, no waiting. - **Rust-native performance.** Near-zero overhead per agent. Memory-safe parallelism via Tokio. - **Independent LLM bindings.** Each agent in the fleet can target a different model or provider. --- ### Installation #### From crates.io (all platforms) ```bash cargo install opendev-cli ``` #### macOS ```bash # Homebrew (recommended) brew install opendev-to/tap/opendev # Shell installer curl --proto '=https' --tlsv1.2 -LsSf https://github.com/opendev-to/opendev/releases/latest/download/opendev-cli-installer.sh | sh # Or download the binary directly from GitHub Releases: # opendev-cli-aarch64-apple-darwin.tar.xz (Apple Silicon) # opendev-cli-x86_64-apple-darwin.tar.xz (Intel) ``` #### Linux ```bash # Shell installer (x86_64 and ARM64) curl --proto '=https' --tlsv1.2 -LsSf https://github.com/opendev-to/opendev/releases/latest/download/opendev-cli-installer.sh | sh # Or download the binary directly from GitHub Releases: # opendev-cli-x86_64-unknown-linux-gnu.tar.xz (x86_64) # opendev-cli-aarch64-unknown-linux-gnu.tar.xz (ARM64 / Raspberry Pi) ``` #### Windows ```powershell # PowerShell installer powershell -ExecutionPolicy ByPass -c "irm https://github.com/opendev-to/opendev/releases/latest/download/opendev-cli-installer.ps1 | iex" # Or download opendev-cli-x86_64-pc-windows-msvc.zip from GitHub Releases ``` #### From source (all platforms) Requires [Rust](https://rustup.rs/) 1.94+. ```bash git clone https://github.com/opendev-to/opendev.git cd opendev cargo build --release -p opendev-cli # Binary at target/release/opendev (or opendev.exe on Windows) ``` If you use the repo for development, you may also have a local symlink at `~/.local/bin/opendev` pointing at `target/release/opendev`. That can take precedence over the Homebrew binary in `/opt/homebrew/bin/opendev`. To test a Homebrew install from a clean shell state: ```bash rm -f ~/.local/bin/opendev hash -r brew uninstall opendev brew untap opendev-to/tap brew tap opendev-to/tap brew install opendev-to/tap/opendev which opendev opendev --version ``` See [DEVELOPMENT.md](./DEVELOPMENT.md) for the full local development and Homebrew testing workflow. > **All release binaries, checksums, and installers are available on the [GitHub Releases](https://github.com/opendev-to/opendev/releases) page.** #### Supported platforms | Platform | Architecture | Binary | |----------|-------------|--------| | macOS | Apple Silicon (M1+) | `opendev-cli-aarch64-apple-darwin.tar.xz` | | macOS | Intel | `opendev-cli-x86_64-apple-darwin.tar.xz` | | Linux | x86_64 | `opendev-cli-x86_64-unknown-linux-gnu.tar.xz` | | Linux | ARM64 | `opendev-cli-aarch64-unknown-linux-gnu.tar.xz` | | Windows | x86_64 | `opendev-cli-x86_64-pc-windows-msvc.zip` | #### Verify installation ```bash opendev --version ``` If Homebrew reports `Not a valid ref: refs/remotes/origin/main` while auto-updating the tap, remove the stale local tap clone and retry: ```bash brew untap opendev-to/tap brew tap opendev-to/tap brew install opendev-to/tap/opendev ``` ### Quick Start ```bash # Set an API key (OpenAI, Anthropic, or Fireworks -- any one will do) export OPENAI_API_KEY="sk-..." # export ANTHROPIC_API_KEY="sk-ant-..." # export FIREWORKS_API_KEY="fw_..." # Start the interactive TUI opendev # Or start the Web UI opendev run ui # Single prompt (non-interactive) opendev -p "explain this codebase" # Resume most recent session opendev --continue ``` Prefer a guided walkthrough? Run `opendev config setup` to interactively choose providers, models, and workflow bindings. See the [Provider Setup Guide](docs/providers.md) for all 9 supported providers, authentication details, and advanced configuration.

OpenDev Web UI

### Multi-Provider Support OpenDev supports 9 LLM providers: **OpenAI**, **Anthropic**, **Fireworks**, **Google**, **Groq**, **Mistral**, **DeepInfra**, **OpenRouter**, and **Azure OpenAI**. Each provider's models can be independently assigned to 5 workflow slots: - **Normal** -- Primary execution model for coding tasks and tool calls - **Thinking** -- Complex reasoning and planning (falls back to Normal) - **Compact** -- Context summarization when history grows long (falls back to Normal) - **Critique** -- Self-critique of agent reasoning (falls back to Thinking) - **VLM** -- Vision/image processing (falls back to Normal if it supports vision) Mix and match providers per slot in `~/.opendev/settings.json`: ```json { "model_provider": "anthropic", "model": "claude-sonnet-4-20250514", "model_thinking_provider": "openai", "model_thinking": "o3" } ``` See the [Provider Setup Guide](docs/providers.md) for the full list of env vars, fallback chains, and configuration options. ### MCP Integration Dynamic tool discovery via the Model Context Protocol for connecting to external tools and data sources. ```bash opendev mcp list opendev mcp add myserver uvx mcp-server-sqlite opendev mcp enable/disable myserver ``` ### Development ```bash git clone https://github.com/opendev-to/opendev.git cd opendev cargo build --workspace cargo test --workspace ``` ```bash cargo check --workspace # Type check cargo clippy --workspace # Lint cargo fmt --all # Format cargo test -p opendev-cli # Test a specific crate ``` Detailed local-dev, symlink, Homebrew, and release-testing notes are in [DEVELOPMENT.md](./DEVELOPMENT.md). ### Web UI The frontend is a React/Vite app in `web-ui/`: ```bash cd web-ui && npm ci && npm run build ``` ### Contributing If you're interested in contributing to OpenDev, please open an issue or submit a pull request. --- ### How OpenDev Compares - **vs. Claude Code / Codex CLI / Gemini CLI:** Closed-source tools that lock you into a single provider. OpenDev is fully open source and lets you mix models from any provider, independently bound per workflow (execution, thinking, critique, compaction, vision). - **vs. OpenCode:** OpenCode is a great open-source coding agent with TUI, Web UI, and LSP support. However, its architecture is not modular enough to support per-workflow model binding, concurrent multi-agent sessions, or compound AI orchestration. - **vs. OpenClaw:** OpenDev and OpenClaw share similar concepts around autonomous AI agents. The key difference is focus: OpenDev is purpose-built for the software development lifecycle, with context engineering, structured agent workflows, and deep code understanding. --- ### Star History

Source: https://github.com/opendev-to/opendev

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OpenDev Terminal