# unch [](https://github.com/uchebnick/unch/releases/latest) [](https://github.com/uchebnick/homebrew-tap) [](https://github.com/uchebnick/unch/actions/workflows/ci.yml) [](https://github.com/uchebnick/unch) [](https://unch.mintlify.app/) [](https://t.me/unchchat) **Semantic code search for code symbols and docs.** `unch` indexes functions, methods, types, classes, interfaces, and attached docs with Tree-sitter, then lets you search them from the terminal. It is useful when you know what the code does, but not the symbol name or file path. Local `llama.cpp` embeddings are the default; OpenRouter and remote publishing are opt-in.

## Why `unch` - **Indexes symbols, not just lines.** `unch` stores top-level API objects and attached docs for `Go`, `Rust`, `TypeScript`, `JavaScript`, and `Python`. - **Keeps the local workflow simple.** Build an index once, search from the CLI, and keep everything on your machine unless you explicitly choose OpenRouter embeddings or publish a remote index. - **Still works with CI.** If you want a shared index, GitHub Actions publishing is available, but it is not required for the normal local flow. ## Install npm is the recommended install path: ```bash npm install -g @uchebnick/unch unch codex install ``` It installs the `unch` CLI and downloads the matching native release binary for your platform. Run `unch codex install` once to register unch in Codex through `codex mcp add` and install the `unch` skill in `~/.codex/skills/unch/SKILL.md`, then restart Codex. Homebrew on macOS: ```bash brew install uchebnick/tap/unch ``` Release installer on macOS and Linux: ```bash curl -fsSL https://raw.githubusercontent.com/uchebnick/unch/main/install.sh | sudo sh -s -- -b /usr/local/bin ``` This installs `unch` into a system `PATH` directory so you can run it immediately after the installer finishes. On Apple Silicon macOS, use `/opt/homebrew/bin` instead of `/usr/local/bin`: ```bash curl -fsSL https://raw.githubusercontent.com/uchebnick/unch/main/install.sh | sudo sh -s -- -b /opt/homebrew/bin ``` PowerShell installer on Windows: ```powershell iwr https://raw.githubusercontent.com/uchebnick/unch/main/install/install.ps1 -useb | iex ``` This makes `unch` available immediately in the current PowerShell session. To keep it available in future PowerShell or terminal sessions, add `$HOME\AppData\Local\Programs\unch\bin` to your user `PATH`. Source install: ```bash go install github.com/uchebnick/unch/cmd/unch@latest ``` This install path requires a cgo-capable Go toolchain. It is smoke-tested in CI in the official Debian-based Go container image. To pin a specific release, use `@`. If you want to build from the current checkout: ```bash go build -o unch ./cmd/unch ``` Published release archives: - macOS: `arm64`, `x86_64` - Linux: `arm64`, `x86_64` - Windows: `arm64`, `x86_64` (`unch.exe`) On those targets, the installers use published release archives by default, so Go is not required. `install.sh` and `install/install.ps1` only fall back to `go install` when no matching archive is available. `install.sh` is smoke-tested in CI on Ubuntu, Debian, Arch, and NixOS-like environments, including the default no-`-b` path selection flow; the PowerShell installer is smoke-tested on Windows `arm64` and `x86_64`. Verify the installed binary: ```bash unch --version unch --help ``` See [Compatibility](docs/compatibility.md) for the support matrix and upgrade rules, and [Benchmarks](docs/benchmarks.md) for the checked-in `smoke`, `ci`, and `default` suites. Model selection accepts either a known model id or a direct `.gguf` path: ```bash unch index --model embeddinggemma unch index --model qwen3 unch search --model qwen3 "create a new router" ``` OpenRouter is also supported as an embedding provider: ```bash unch auth openrouter --token sk-or-... unch index --provider openrouter --model openai/text-embedding-3-small unch search --provider openrouter --model openai/text-embedding-3-small "create a new router" ``` By default `unch auth openrouter` writes `~/.config/unch/tokens.json`, so you do not need to keep the token in your shell environment. Use `--local` if you want to store it in `.semsearch/tokens.json` for one repository. ## Quick Start ```bash cd path/to/repo unch index --root . unch search "create a new router" unch search --details "get path variables from a request" ``` OpenRouter flow: ```bash cd path/to/repo unch auth openrouter --token sk-or-... unch index --root . --provider openrouter --model openai/text-embedding-3-small unch search --provider openrouter --model openai/text-embedding-3-small "create a new router" ``` Real output from indexing [`gorilla/mux`](https://github.com/gorilla/mux): ```text $ unch index --root . Loaded model dim=768 Indexed 278 symbols in 16 files $ unch search "create a new router" 1. mux.go:32 0.7747 2. mux.go:314 0.8135 $ unch search --details "get path variables from a request" 1. mux.go:466 0.7991 kind: function name: Vars signature: func Vars(r *http.Request) map[string]string docs: Vars returns the route variables for the current request, if any. ``` The first local `llama.cpp` run may download the default embedding model, fetch local `yzma` runtime libraries, and create `./.semsearch/`. Each provider and model pair keeps its own active index snapshot. Rebuilding `openrouter/openai/text-embedding-3-small` does not replace the active `llama.cpp/embeddinggemma` snapshot until the new run finishes successfully. ## MCP for Codex The recommended MCP setup is through the npm wrapper: ```bash npm install -g @uchebnick/unch unch codex install ``` Then restart Codex. The setup command registers the `unch` MCP server and installs the `unch` skill in `~/.codex/skills/unch/SKILL.md`. After restart, ask Codex a codebase question as usual. The skill tells Codex to use these MCP tools before broad file reads: - `workspace_status` to inspect the repository root, state directory, active provider/model, and index status - `search_code` to search indexed code symbols before opening many files - `index_repository` to build or refresh the index when needed - `remote_sync_index` to refresh from a bound GitHub Actions index before rebuilding locally - `create_ci_workflow`, `bind_remote_ci`, and `remote_download_index` when you ask Codex to set up or use remote CI-backed indexes All MCP tools accept an optional `directory` argument. The installed skill passes the active repository path so `unch` searches the workspace Codex is currently editing, even if the MCP server was launched from somewhere else. Codex starts the stdio server for you with `unch start mcp`; you normally do not need to run that command by hand. ## What It Supports Today - Tree-sitter indexing for `Go`, `Rust`, `TypeScript`, `JavaScript`, and `Python` - Top-level API objects and attached documentation - Local indexing and search first, optional remote publishing through GitHub Actions - `auto`, `semantic`, and `lexical` search modes - Legacy `--comment-prefix` and `--context-prefix` only for `index` fallback on unsupported files or parser failures ## Core Commands ### `index` Build or refresh the local index for a repository. ```bash unch index --root . ``` Useful flags: - `--exclude` to skip generated, vendor, or irrelevant paths - `--provider` to switch between local `llama.cpp` embeddings and remote `openrouter` - `--model` to use `embeddinggemma`, `qwen3`, or a custom `.gguf` path - `--ctx-size` to override the selected model context size; `0` uses the model default - `--lib` to use an existing `yzma` runtime directory - `--state-dir` to keep index state in a custom `.semsearch` directory ### `search` Query the current index. ```bash unch search "sqlite schema" unch search --mode lexical "Run" ``` Useful flags: - `--mode` for `auto`, `semantic`, or `lexical` - `--limit` to control result count - `--max-distance` to narrow semantic matches - `--provider` to select the embedding provider that matches the indexed snapshot - `--model` to search with `embeddinggemma`, `qwen3`, or a custom `.gguf` path - `--ctx-size` to override the selected model context size; `0` uses the model default - `--state-dir` to search against a custom `.semsearch` directory - `--details` to print symbol metadata, signature, docs, and body context for each match ## Remote / CI Remote indexing is optional. Use it when you want GitHub Actions to publish an index for a repository. The generated workflow file is `.github/workflows/unch-index.yml`. Create the workflow scaffold: ```bash unch create ci ``` Bind the local repository state to a GitHub repo or workflow URL: ```bash unch bind ci https://github.com/uchebnick/unch ``` After the workflow is committed and runs successfully once, `unch search` can refresh the published index automatically when a newer remote version exists. Use `unch remote sync` when you want to force a refresh before searching. The cross-platform benchmark matrix stays separate from ordinary push CI. It runs on release-tag pushes and manual `workflow_dispatch`, uses the checked-in `ci` suite with a lighter `1 cold / 1 warm / 1 search repeat` profile, and publishes per-platform summaries for Linux, macOS, and Windows. ## Contributing and Feedback - See [CONTRIBUTING.md](CONTRIBUTING.md) for the local dev loop. - Open a [bug report](https://github.com/uchebnick/unch/issues/new?template=bug_report.md) if search quality or indexing behavior looks wrong. - Open a [feature request](https://github.com/uchebnick/unch/issues/new?template=feature_request.md) if you want new language support, ranking behavior, or workflow features.