anchor

A small coding agent for the terminal. Bring your own key and your own model: it works in one directory through a handful of tools, and a deterministic harness decides what it may touch.

Documentation: fuseraft.ai/anchor

• Your model, your key. Claude, OpenAI and xAI, or any server that speaks the OpenAI API: your company's LLM gateway, OpenRouter, a LiteLLM proxy, or a local model in Ollama, vLLM or LM Studio. Name a server once and use its models as work/<model>; switch with /model mid-session. Set how hard the model thinks with /effort, and watch its thinking as it streams.
• Safe by default. Writes, most shell commands and reads outside the directory ask first, with a diff for every write. Secret files and dangerous commands are always denied, even with --yolo. An "always" answer is remembered per directory, in ~/.anchor.
• Full-screen terminal UI. Streaming Markdown with highlighted code, @path attachments, search, history and /copy. --plain gives a line-by-line REPL.
• Themes. Built-in themes, sample themes and your own in small JSON files, with hex colors and full-screen backgrounds.
• Long sessions. Older turns are summarized to fit the context window. Sessions resume, and /undo reverts a turn's file changes.
• Extensible. Sub-agents, Agent Skills and MCP servers, all behind the same approval checkpoint.
• Scriptable. -p runs one prompt, --json streams events, and --until keeps going until a check passes.

Status: 0.10.1. Linux, macOS and Windows (shell commands run in Git for Windows' bash).

Install

curl -fsSL https://raw.githubusercontent.com/fuseraft/anchor/main/install.sh | bash   # Linux, macOS
irm https://raw.githubusercontent.com/fuseraft/anchor/main/install.ps1 | iex          # Windows (PowerShell)
brew install fuseraft/tap/anchor                                                     # Homebrew

Or use Scoop (scoop bucket add fuseraft https://github.com/fuseraft/scoop-bucket, then scoop install anchor), grab a release, or build with ./build.sh (.NET 10 SDK). Script installs update themselves; see Install.

Configure

Run anchor setup. It asks where your models come from (Anthropic, OpenAI, xAI, or your own server's URL), keeps the key in your OS keychain where there is one, and lets you pick a model.

To use more than one server, such as your team's gateway and a model on your laptop, name each in ~/.anchor/config.json. See Configuration for named providers, local servers, custom headers and reasoning effort.

Use

anchor                                   # interactive
anchor --resume                          # continue the latest session here
anchor -p "why does the build fail?"
git diff | anchor -p "review this change"
anchor -p --yolo "fix the failing tests" --until "dotnet test"

In the REPL, /help lists the commands, !cmd runs a command in your own shell, and Ctrl+C cancels a turn. AGENTS.md in the directory is added to the system prompt.

Themes

/theme lists the themes and switches between them: default, bright, light, mono and rust are built in. For more, copy one of the sample themes (ember, tide, forest, neon, phosphor, paper) into ~/.anchor/themes/:

mkdir -p ~/.anchor/themes
curl -fsSL https://raw.githubusercontent.com/fuseraft/anchor/main/themes/ember.json -o ~/.anchor/themes/ember.json

Then /theme ember, or "theme": "ember" in the config. /theme save <name> writes the current colors to a file to start your own; Making a theme explains the format.

Learn more

Safety · Work until a check passes · Sub-agents · Skills · MCP · Scripting · JSON protocol · Commands

Develop

DESIGN.md explains how anchor is put together and why. ./build.sh runs the tests and publishes bin/anchor; dotnet test runs just the tests (they need git and python3). The docs site in docs/ is built with Starlight: npm install && npm run dev there to preview, and pushes to main deploy it.

License

MIT