A faster, cheaper, lighter terminal coding agent.
- Automatic model fallback
- Request trimming plus compaction
- Streaming tool early execution
- Small memory footprint
- Import Claude Code, Codex, and OpenCode sessions
- Vim-style keyboard controls
If you already have Go 1.27.0+ installed:
go install github.com/keakon/chord/cmd/chord@latestSource builds require Go 1.27.0 or newer; the default GOTOOLCHAIN=auto downloads the required toolchain when needed.
If you do not have Go 1.27.0+, download the archive for your OS/architecture from GitHub Releases, extract it, put chord on your PATH, and run:
chord --versionOn macOS, the downloaded binary may be blocked on first run because it came from the internet and is not notarized; see Quickstart for the xattr / codesign commands that unblock it.
Open your project in an interactive terminal:
cd my-project
chordIf config.yaml is missing, Chord launches a one-time setup wizard: it creates the minimal config.yaml and, when needed, auth.yaml, then prints the exact paths it used.
To write YAML manually or use a different provider/model setup, see Quickstart.
Describe what you want and press Enter. For example, have it read through your project first:
Explain this project's main modules and how to run its tests. Do not change any files yet.
Inspect the response and tool results. Once you know your way around, ask Chord to make a specific change.
For manual provider/model setup and the limit fields, see Quickstart and the Glossary; ready-to-paste config.yaml files are in the configuration examples.
- Quickstart: install and complete your first task
- Usage: everyday controls, session recovery, and long tasks
- Choosing models · Model configuration recipes · Configuration examples: pick a channel, then connect it
- Permissions & Safety: choose which actions need approval
- Long tasks: keep implementation, checks, and fixes moving
- Customization: configure roles, skills, code diagnostics, and external tools
- Headless: control Chord from another interface with
chord headless - ACP agent mode: drive Chord from ACP clients such as Zed with
chord acp - Troubleshooting · Full documentation index
Six agent harnesses ran the same DeepSWE v1.1 task: adding streaming JSON iteration to httpx. All six runs used deepseek-v4.1-flash. Chord 0.8.1 finished first and cheapest: 6m37s and $0.052, using 54.5K input tokens, 2.96M cache-read tokens, and 58.6K output tokens. The next-best run took 1.49× as long and cost 1.51× as much.
| Harness | Time | Cost |
|---|---|---|
| Chord 0.8.1 | 6m37s | $0.052 |
| deepseek-harness 0.1.5-rc.1 | 9m50s (1.49×) | $0.079 (1.51×) |
| pi 0.85.1 | 10m22s (1.57×) | $0.086 (1.65×) |
| codex 0.154.0 | 17m01s (2.57×) | $0.139 (2.67×) |
| mini-swe-agent 2.4.6 | 18m29s (2.79×) | $0.125 (2.40×) |
| claude code 2.1.272 | 22m25s (3.39×) | $0.166 (3.17×) |
Multipliers are relative to Chord.
Measured on macOS 15.3.2 (arm64).
| Harness | Empty session | 200 messages | Growth |
|---|---|---|---|
| Chord 0.8.1 | 30MB | 39MB | +9MB |
| codex 0.154.0 | 27MB | 47MB | +20MB |
| claude code 2.1.273 | 143MB | 216MB | +73MB |
One measured task and one memory scenario; your numbers will differ. Full tables, methodology, and implementation notes: Performance.
- Companion: keakon/chord-gateway
- Contributing
- Changelog
- Issues
Chord is developed and tested primarily on macOS. Linux works well; Windows mostly works but may have undiscovered bugs. Some features (prevent_sleep) are macOS-only and silently no-op elsewhere. See Platform support for the per-feature matrix.
Chord is built on Bubble Tea, with design and feature inspiration from Claude Code, Codex, OpenCode, and Crush. Most of its development was assisted by GPT-5.4/5.5. Thanks to the many community-run API proxies on linux.do for providing token access.
MIT License. See LICENSE.