parecode

An MCP server that gives coding agents context-window-aware search and safe, atomic multi-file edits — built to cut token usage on large codebases without giving up correctness.


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Requirements

• Node.js 20 or newer (ESM, native test runner, stable fetch-free runtime).
• ripgrep on PATH (rg on Linux/macOS, rg.exe on Windows). Install via your package manager:
• macOS: brew install ripgrep
• Debian/Ubuntu: apt install ripgrep
• Windows: winget install BurntSushi.ripgrep.MSVC or choco install ripgrep
• A supported MCP client (Claude Code is the reference target).

Parecode does not bundle ripgrep — it shells out to the system binary so you stay on a single, audited version.

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Install

npm install -g parecode

Pure JavaScript — no native dependencies, no C/C++ toolchain required.

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Quick start

Register the server with Claude Code:

parecode init                       # user scope; installs MCP + SessionStart hook + parecode-explore plugin (defaults)
parecode init --scope project       # commit MCP config + hook to the repo
parecode init --no-hook             # register MCP only; skip the SessionStart hook
parecode init --no-plugin           # skip the parecode-explore Claude Code plugin
parecode init --print               # print the equivalent command without running it
parecode init --remove-hook         # remove the SessionStart hook (MCP stays registered)
parecode init --remove-plugin       # uninstall the parecode-explore Claude Code plugin

The SessionStart hook injects a short directive at the start of each session telling Claude to prefer ParecodeSearch / ParecodeEdit over the equivalent native tools. Without it, Claude's first-party Grep / Read / Edit tools typically win by default and Parecode's token savings never land. The hook payload is a static string; parecode hook session-start prints it. Pass --no-hook if you would rather opt in explicitly per session via your own tooling.

The bundled parecode-explore Claude Code plugin adds a read-only subagent (pinned to Haiku, given only ParecodeSearch) and a matching skill, so exploration-style questions ("where is X?", "how does Y work?", "find all usages of Z") get answered in a cheap, isolated context window instead of burning tokens in your main session. init registers a local marketplace pointing at the npm-installed copy and runs claude plugin install parecode-explore@parecode. If your Claude Code build doesn't support the plugin subcommand the step soft-fails with a warning and the rest of init still succeeds; pass --no-plugin to skip it entirely, or --with-plugin to make any plugin-step failure hard-fail.

Then in any session, the ParecodeSearch, ParecodeExpand, and ParecodeEdit tools become available. Run parecode doctor to confirm registration, hook status, and .codegraph/ pairing if present.

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What it does

• ParecodeSearch — ripgrep-backed search that returns matches with surrounding context windows in a single call, with per-file byte chunking so large result sets do not blow up your context.
• pattern accepts a single string or an array of strings; arrays dispatch parallel ripgrep runs sharing the same paths / contextLines, and each match carries a patterns: string[] field listing which input patterns contributed. One call replaces N back-to-back greps for related-keyword flow tracing.
• Overlapping or adjacent windows within the same file are merged automatically (gap ≤ contextLines), with bridging lines loaded from disk.
• Per-match and response-level estimatedTokens are returned so the agent can self-budget before consuming results.
• Opt-in relatedSymbols: true surfaces likely event-flow neighbours (Handle<X>, On<X>, <X>Handler/Listener/Closed/Completed/Started) discovered in each match, capped at 10.
• Omitted line ranges are reported so the agent can widen with ParecodeExpand without re-reading the whole file.
• ParecodeExpand — widen a known (file, startLine, endLine) range with optional contextBefore / contextAfter padding. Designed as the natural follow-up to a ParecodeSearch match. Returns the same estimatedTokens shape so the same self-budgeting heuristic applies. Prefer this over a full-file Read after locating a line.
• ParecodeEdit — batched multi-file edits with whitespace-tolerant fuzzy matching (and an opt-in Unicode-lookalike mode), pre/post stat conflict detection, and atomic same-directory rename writes. Cross-file edits run in parallel.
• parecode stats — local JSONL session log with token-saved estimates. Zero network. Zero telemetry.

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Measured savings

On search-and-edit tasks — finding call sites, multi-file refactors, "do X to every Y" — Parecode cut cost ~40% and assistant turns ~75–83% in matched A/B tests:

| repo | task | cost | turns | |---|---|--:|--:| | TypeScript | find every call site of a symbol, edit each (17 sites, 8 files) | −43% | −83% | | Unity / C# | find every call site of a symbol, edit each (11 sites, 5 files) | −41% | −76% |

_Method: the identical task run with Parecode on vs off, a fresh session per run, n=3 per arm with alternated order, Sonnet 4.6. Savings come from collapsing many Grep / Read / Edit round-trips into single ParecodeSearch / ParecodeEdit calls — so the win scales with how much searching and multi-file fan-out a task involves, and shrinks toward zero on single-file or reasoning-heavy tasks. These are measured per-session token and cost numbers, not the estimates in the scan below._

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Retroactive Savings Scan

Curious how much Parecode would have saved you if you had installed it earlier? You can scan your past Claude Code sessions:

parecode stats --retroactive --since 30d

Sample output: ```text Parecode — last 30d (retroactive scan) ───────────────────── Sessions: 42 Tool calls: 156 Calls batched (est): 89 Tokens saved (est): 1,200,000

• Note: Retroactive savings are estimated, not measured.

**Privacy disclaimer:** This scan runs entirely locally against Claude Code's session transcripts (`~/.claude/projects/**`). By default, it parses only structured fields (tool names, paths, patterns, and token counts). It does not send any data over the network. The `--include-content` flag (which allows reading tool input/output) is strictly opt-in and loudly flagged if used.

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## Privacy

Parecode performs **no network calls at runtime**. Session logs are written to your OS data directory (resolved via [`env-paths`](https://github.com/sindresorhus/env-paths)) with `0600` permissions on Unix. Logs are self-maintaining: each server start prunes session data older than 30 days and caps the envelope log at 5 MB. Prune earlier with `parecode prune <days>` or wipe the data dir. Update to the latest release (and refresh hooks/plugin) with `parecode update`.

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## License

[MIT](LICENSE)