Miru (見る)

Hybrid code search for AI coding agents. Find code by meaning, not grep.

Your AI agent finds the code it needs with up to 50% fewer tokens.

Miru returns the best chunks (path, lines, snippet) for questions like "where is auth middleware configured?" — plugged directly into Claude Code, Cursor, Copilot, Codex, and 9+ other agents via MCP.

How it fits into your agent's workflow

Miru replaces the grep/glob-style search agents fall back on today. Install once, and every connected agent gets search and find_related MCP tools automatically.

Install

bun add -g @takara-ai/miru-code

Set up credentials

miru setup

Interactive miru setup defaults to device-code login and saves the resulting credentials locally. Manual bearer-token entry is still available with --key. If credentials are missing, the interactive MCP/plugin path can bootstrap the same device flow automatically on first use.

miru setup --device           # explicit device-code login
miru setup --key YOUR_TOKEN   # store a bearer token directly
miru setup --clear            # remove stored credentials

Miru stores versioned credentials in credentials.json and automatically loads or refreshes them for MCP and CLI use. TAKARA_API_KEY still overrides stored credentials when set explicitly.

Add to your IDE

miru install

Interactive TUI — ↑↓ move, space toggle, a all, enter confirm. Pick agents and integrations:

| Integration | What it does | | ----------------------------- | ------------------------------------------------------------------- | | MCP server | search, locate, expand, and find_related tools in the agent | | Instructions | Search policy in CLAUDE.md / AGENTS.md / GEMINI.md | | Sub-agent | Dedicated miru-code agent file | | Cursor rules | Always-on .cursor/rules/miru-code.mdc (Cursor only) | | Search hooks (experimental) | Block built-in Grep/Glob and redirect to Miru MCP | | Caveman (experimental) | On-demand chat compression skill (/caveman) | | STE writing (experimental) | On-demand clear technical English for docs (/ste) |

Restart the IDE when done.

miru uninstall   # remove miru config

Supported: Cursor · Claude Code · Gemini CLI · Kiro · OpenCode · GitHub Copilot · Codex · VS Code · Visual Studio (Windows) · Windsurf / Devin Desktop

| IDE | MCP | Instructions / rules | Hooks (experimental) | Caveman (experimental) | STE (experimental) | | -------------- | ------------------------------------- | ------------------------------- | ------------------------------------------------- | --------------------------------------------------- | -------------------------------------------- | | Cursor | ~/.cursor/mcp.json | ~/.cursor/rules/miru-code.mdc | ~/.cursor/hooks.json | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | Claude Code | ~/.claude.json | ~/.claude/CLAUDE.md | ~/.claude/settings.json | ~/.claude/skills/caveman/SKILL.md | ~/.claude/skills/ste/SKILL.md | | Gemini CLI | ~/.gemini/settings.json | ~/.gemini/GEMINI.md | ~/.gemini/settings.json (BeforeTool) | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | Kiro | ~/.kiro/settings/mcp.json | ~/.kiro/steering/miru.md | ~/.kiro/settings/hooks.json | ~/.kiro/skills/caveman/SKILL.md | ~/.kiro/skills/ste/SKILL.md | | OpenCode | $XDG_CONFIG_HOME/opencode/opencode.json(c) (else ~/.config/opencode/…) | …/AGENTS.md | …/plugins/miru-search-guard.ts | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | GitHub Copilot | ~/.copilot/mcp-config.json | — | ~/.copilot/hooks/miru-search.json | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | Codex | ~/.codex/config.toml | ~/.codex/AGENTS.md | ~/.codex/hooks.json | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | VS Code | …/Code/User/mcp.json | — | ~/.copilot/hooks/miru-search.json | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | Visual Studio | %USERPROFILE%\.mcp.json | — | ~/.copilot/hooks/miru-search.json | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md | | Windsurf | — | — | ~/.codeium/windsurf/hooks.json | ~/.agents/skills/caveman/SKILL.md | ~/.agents/skills/ste/SKILL.md |

Plugin packaging

This repo now includes plugin packaging for:

• Codex: .codex-plugin/plugin.json and .agents/plugins/marketplace.json
• Claude Code: .claude-plugin/plugin.json and .claude-plugin/marketplace.json
• Cursor: plugin.json and .cursor/rules/miru-code-search.mdc

Current limitation:

• these plugin manifests still launch the published Miru runtime through bunx @takara-ai/miru-code
• that means local source edits do not affect plugin behavior until a package version is published
• and a fully self-contained “no Bun required” plugin install is still future work

Search hooks

Sub-agent files are also written where supported (see miru install plan). Windsurf hooks only (experimental) — no MCP entry yet. Caveman is an on-demand Agent Skill (default off): invoke with /caveman or “talk like caveman”; stop with “normal mode”. Invocation UI varies by IDE (/caveman, $caveman, @caveman, etc.). Most IDEs share ~/.agents/skills/caveman/SKILL.md (including Copilot / VS Code / Visual Studio); Claude Code and Kiro keep vendor-native skill dirs. Ownership is tracked on the shared path so uninstalling one IDE keeps the skill while another still owns it; selecting all owners removes it once. STE is an on-demand Agent Skill (default off): invoke with /ste or “de-slop this”; keep articles and complete sentences. Most IDEs share ~/.agents/skills/ste/ the same way (ownership via miru-owners.json); Claude Code and Kiro keep vendor-native STE dirs.

STE helps write clear technical English for docs, runbooks, errors, and release notes (pragmatic ASD-STE100-inspired rules). Invoke with /ste or “de-slop this”. Keep articles and complete sentences — not telegraph-style omission.

Not ASD-certified. Full dictionary compliance needs the official standard at asd-ste100.org. Miru does not ship the copyrighted ASD dictionary.

Not for marketing or brand copy. Off by default; enable STE in the installer for any supported IDE. Restart the IDE (or reload skills) after install. For Codex, install also sets [features] skills = true in ~/.codex/config.toml (same as Caveman).

Caveman compresses live chat replies (less filler, max meaning). Intensities: /caveman lite|full|ultra (default full). Persisted artifacts (commits, PRs, customer docs) stay normal prose unless you ask otherwise.

Security / destructive warnings use clear normal prose (auto-clarity) — brevity never hides risk. Session token savings vary; the skill itself costs input tokens. No guaranteed %.

Off by default at install time. Enable Caveman in the installer for any supported IDE. Restart the IDE (or reload skills) after install. For Codex, the installer also sets [features] skills = true in ~/.codex/config.toml (required for Codex to load skills).

Search hooks are experimental — behavior and IDE support may change between releases.

Hooks run miru hook-guard before built-in search tools execute. They block conceptual Grep/Glob/SemanticSearch and shell rg/grep/find, and tell the agent to use Miru MCP search (or locate for exact literals) instead. Exact literal lookups (e.g. REDIS_HOST, a symbol name) still pass through.

Hooks are off by default at install time. Enable them in the installer if you want built-in Grep/Glob redirected to Miru MCP.

Team sub-agent in a repo (optional):

miru init --agent claude --force

Try it

Meaning-based questions → search. Exact strings (env vars, symbols, error codes) → locate.

miru search "auth middleware" ./src
miru locate REDIS_HOST ./src
miru expand src/auth.ts 42 ./src
miru find-related src/auth.ts 42 ./src

Terminal output is human-readable; use --json for scripts. One-off without installing:

bunx @takara-ai/miru-code search "auth middleware" ./src

MCP tools

When wired via miru install, the MCP server exposes search, locate, expand, and find_related. read_benchmark appears only in benchmark mode. Pass the project root as repo for local workspaces (or an https:// git URL). The index is built on the first call and cached for the session.

| Tool | When to use | | ---------------- | --------------------------------------------------------------------------------------- | | search | Default for code exploration — hybrid semantic + keyword search. One call per question. | | locate | Exact substrings (env vars, symbols, error codes) — prefer over Grep. | | expand | More context in the same file when a hit has truncated: true. | | find_related | Similar code in other files from a file_path + anchor_line. | | read_benchmark | Cumulative token-savings rollup (benchmark mode only). |

Workflow

1. search with query + repo — returns compact snippets (~±15 lines) and relevance scores.
2. If a hit has truncated: true, call expand with file_path, anchor_line, and repo — not another search or a full-file read.
3. To trace similar patterns elsewhere, call find_related with the same file_path, anchor_line, and repo.
4. Use your editor's Read on absolute_path only when editing or when expand still lacks context.

Prefer these tools over Grep, Glob, or SemanticSearch when Miru MCP is connected — hooks and instructions enforce that when enabled.

Local repo hits include absolute_path for one-click navigation. Parameter reference is below under MCP parameters.

How it works

Hybrid search: Takara embeddings + BM25 + fusion + reranking. Index code, docs, config, or all with --content.

MCP watches local files and updates the index incrementally. Package upgrades invalidate stale caches via the version epoch.

| OS | Index cache | |----|-------------| | macOS | ~/Library/Caches/miru | | Linux | ~/.cache/miru | | Windows | %LOCALAPPDATA%\miru\Cache |

Chunking & languages

Miru chunks source in tiers: AST (tree-sitter, default) → structural heuristics → line splits.

AST chunking — 22 languages (syntax-aware boundaries via vendored web-tree-sitter grammars):

| Language | Typical extensions | |----------|-------------------| | bash | .sh, .bash, .zsh | | c | .c | | cpp | .cpp, .h, .hpp, etc. | | csharp | .cs | | css | .css | | dart | .dart | | elixir | .ex, .exs | | embeddedtemplate | ERB-style templates | | go | .go | | haskell | .hs | | html | .html | | java | .java | | javascript | .js, .jsx, .mjs, .cjs | | json | .json | | ocaml | .ml, etc. | | php | .php | | python | .py, .pyi | | ruby | .rb | | rust | .rs | | scala | .scala | | solidity | .sol | | typescript | .ts, .tsx, .mts, .cts |

Structural fallback (brace/indent heuristics when AST is unavailable): python, go, typescript, javascript, cpp, c.

Line fallback: everything else that gets indexed (kotlin, swift, vue, sql, etc.) — still searchable, coarser chunks.

Set MIRU_AST_CHUNKING=0 to disable AST and use structural → lines only.

CLI reference

Run miru -h for the command list, or miru <command> -h for details.

| Command | Purpose | | ----------------------------------------- | --------------------------------------------------------------------------------- | | miru setup | Authenticate and store credentials | | miru install | Configure IDE (global) | | miru uninstall | Remove IDE config | | miru search <query> [path] | Search (-k N, --content, --json) | | miru locate <literal> [path] | Exact substring in the index | | miru expand <file> <line> [path] | Adjacent chunks in the same file | | miru find-related <file> <line> [path] | Related chunks | | miru benchmark on/off/status/clear | Toggle MCP benchmark mode / clear report | | miru init --agent <id> | Project-local sub-agent | | miru clear [path] | Drop index cache (use after big CLI-only refactors) | | miru hook-guard | PreToolUse hook entrypoint (experimental); used by installers, reads JSON stdin | | miru | Start MCP server (--benchmark for comparisons) |

CLI uses hyphens (find-related); MCP tool names use underscores (find_related).

Library

bun add @takara-ai/miru-code

import { MiruIndex } from "@takara-ai/miru-code";

const index = await MiruIndex.fromPath("./src");
const results = await index.search({ query: "BM25 tokenize", topK: 10 });

Environment

| Variable | Notes | | ----------------------------- | ------------------------------------------------------------------------ | | TAKARA_API_KEY | Required | | MIRU_OPENAI_BASE_URL | Default https://infer.takara.ai/v1 | | MIRU_OPENAI_EMBEDDING_MODEL | Default ds1-miru-int8 | | MIRU_WORKSPACE_ROOT | Optional: restrict MCP local repo paths to this directory | | MIRU_MAX_INDEX_FILES | Cap files indexed per operation | | MIRU_ALLOW_HTTP_GIT | Set 1 to allow plain http:// git clones | | MIRU_MCP_WATCH | Set 0 to disable MCP file watch | | MIRU_AST_CHUNKING | Set 0 to disable tree-sitter AST chunking | | MIRU_BENCHMARK_HISTORY_PATH | Override; see Benchmark mode | | MIRU_QUIET | Set 1 to skip the framed CLI banner (subtitle only on color terminals) | | NO_COLOR | Disable CLI colors |

See .env.example for more.

Privacy and API usage

Miru sends file contents to the Takara inference API when building an index and when embedding search queries. Chunks from your repo are transmitted over HTTPS to generate embeddings. API usage may incur cost depending on your Takara plan.

If you index proprietary code, make sure that sending snippets to Takara's endpoint fits your security and compliance requirements. MIRU_WORKSPACE_ROOT is an opt-in boundary for MCP local repo paths only, and restricts indexing to a single workspace directory when set.

Enterprise self-hosted embeddings (no Takara egress): see docs/self-hosted-sagemaker.md.

Benchmark mode

Optional measurement of how many tokens Miru saves versus a simple Grep workflow (ripgrep + reading the top matched file). Useful when evaluating Miru; leave it off day-to-day. Only local repo paths are compared — git URL repos skip the comparison and return benchmark_skipped: "local_repo_only".

miru benchmark on       # add --benchmark to installed MCP configs
miru benchmark status
miru benchmark off      # prefer off when finished measuring
miru benchmark clear    # delete the global report

Restart agents after changing mode. miru install keeps --benchmark if it was already enabled.

While on, each search / locate response includes a compact benchmark block (save_pct, miru_tok, grep_tok, saved_tok, rank1). Call read_benchmark for a cumulative rollup (or ask the agent when you want totals).

History is global (not per-repo) under Miru's state directory:

| OS | Default path | | ------- | ---------------------------------------------------------------------------- | | macOS | ~/Library/Application Support/miru/benchmark-history.json | | Linux | ~/.config/miru/benchmark-history.json ($XDG_CONFIG_HOME/miru/… when set) | | Windows | %APPDATA%\miru\benchmark-history.json |

Override with MIRU_BENCHMARK_HISTORY_PATH. Append-only JSONL of compact token deltas (no query text); read_benchmark returns cumulative totals. Stored in plaintext — miru benchmark clear or uninstall on shared machines.

MCP parameters

**search**

| Param | Required | Notes | | ---------------- | -------- | --------------------------------------- | | query | yes | Natural language or code query | | repo | yes | Project root or git URL | | top_k | no | Results to return (default 3, max 10) | | dedupe_by_file | no | Keep best hit per file (default true) |

**locate**

| Param | Required | Notes | | ------------- | -------- | ----------------------------------------------------------------------------------- | | literal | yes | Exact substring to find | | repo | yes | Project root or git URL | | mode | no | count · locations · lines (default). Prefer count/locations when possible | | limit | no | Cap returned hits. Omit to return all matches | | ignore_case | no | Case-insensitive match (default false) |

**expand**

| Param | Required | Notes | | ------------------ | -------- | --------------------------------------------------------------------- | | file_path | yes | From hit file_path or absolute_path (local repos) | | anchor_line | yes | From the search hit (anchor_line when truncated, else start_line) | | repo | yes | Same repo as the search | | before / after | no | Extra chunks before/after anchor (default 1 each) |

**find_related**

| Param | Required | Notes | | ------------- | -------- | -------------------------------------------- | | file_path | yes | From a search hit | | anchor_line | yes | From the search hit | | repo | yes | Same repo as the search | | top_k | no | Related chunks to return (default 3, max 10) |

**read_benchmark** (benchmark mode only)

| Param | Required | Notes | | ------ | -------- | ---------------------------------------------------------------------- | | repo | no | Filter rollup to one local path or git URL. Omit for all saved queries |

Manual MCP (skip miru install)

{
  "miru": {
    "command": "miru",
    "args": []
  }
}

For benchmark mode, set "args": ["--benchmark"] (or append that flag). Prefer miru benchmark on after a normal install — it updates every agent config.

Run miru setup once so the server can load credentials from credentials.json. If the MCP server starts in an interactive terminal without stored credentials, it will start device login automatically.

Use bunx + @takara-ai/miru-code if miru is not global. Wrapper key varies by IDE (mcpServers, servers, or mcp).

Developing

git clone https://github.com/takara-ai/miru-code.git && cd miru-code
bun install && cp .env.example .env.local
bun test && bun run typecheck

See CONTRIBUTING.md for pre-commit hooks, commit message conventions, and the PR process.

Local MCP: "command": "bun", "args": ["/path/to/miru-code/src/cli.ts"]

miru -h / setup print a framed wordmark on color terminals (MIRU_QUIET=1 for subtitle only). Crane art lives in src/brand-banner.ts; regenerate with bun run scripts/render-crane-art.ts (ImageMagick). The crane is a registered mark of Takara.ai Ltd.

Codex plugin in this repo

This repo includes a repo-local Codex plugin:

• .codex-plugin/plugin.json
• .mcp.json
• .agents/plugins/marketplace.json

The plugin intentionally launches the published package with bunx @takara-ai/miru-code instead of the checked-out source tree, so local source edits here do not affect the Codex plugin until a new package version is published.

Credits

Miru uses work by MinishLab. Thank you to its authors.

• semble (MIT). Miru ports parts of semble. These parts include the file walker, the index layout, the BM25 tokenizer, the hybrid search pipeline, and the ranking signals.
• potion-code and Model2Vec (MIT). The WordPiece tokenizer in tokenizer/tokenizer.json comes from potion-code.

See NOTICE for the licence text and the Model2Vec citation.

License

MIT