Power your agent
คำสั่งของผู้เผยแพร่เอง ไม่ใช่เอนด์พอยต์ของ PlugMCP
Host a copy with our keys and logs.
npx -y @alliecatowo/[email protected]Claude Code ไม่มีลิงก์ติดตั้งสำหรับคำสั่งแบบโลคัล ให้คัดลอกคำสั่งด้านล่างแล้วรันในเทอร์มินัล
claude mcp add io.github.alliecatowo-git-why -- npx -y @alliecatowo/git-why@0.2.0รันในเทอร์มินัล
{ "mcpServers": { "io.github.alliecatowo-git-why": { "command": "npx", "args": [ "-y", "@alliecatowo/[email protected]" ] } }}claude_desktop_config.json
URL แบบรีโมตหรือคำสั่งบนเครื่องของคุณ? การติดตั้งสองแบบต่างกันอย่างไร
รันบน PlugMCP
A new server you create. It is not this listing's official endpoint. Use the publisher install when you want their URL and their credentials.
เปิดLocal-first semantic + full-text search over Git history. It returns the actual commit, its author's real words, and the relevant diff. It retrieves evidence; it does not generate an explanation of its own.
Real output from mise run demo, which rebuilds a small fixture repository
from bench/fixtures/demo/build.mjs and runs these two queries against it.
Nothing here is hand-written, and you can reproduce it in one command.
For output against real repositories — curl, zod, redis — including a
worked case where this is the wrong tool, see
docs/examples.md or the
recorded terminal sessions.
$ git why "that bizarre bug where reconnecting subscribed twice"
1. 7deab42 Stop duplicate subscriptions after reconnect
2025-11-20 · Maya Chen
Reconnecting re-ran the subscribe handler without clearing the previous
registration, so every reconnect doubled the delivered events.
src/net/socket.ts
-export function connect(url) { return new Socket(url); }
+export function connect(url) {
+ const s = new Socket(url);
+ s.on('reconnect', () => resubscribeOnce(s));
+ return s;
+}
$ git why "why do we keep the session when the refresh token is empty?"
1. f17db20 Fix infinite token-refresh loop
2025-11-03 · Maya Chen
Provider X can return an empty refresh token while the current access
token remains valid. Retrying here puts clients into an infinite loop.
src/auth/refresh.ts
export function refresh(session, refreshToken) {
- if (!refreshToken) throw new InvalidTokenError();
+ if (!refreshToken) return session;
return exchange(refreshToken);
}
Install from npm (Node >= 22.12):
npm install -g @alliecatowo/git-why
Or with Homebrew (macOS and Linux; pulls in node):
brew install alliecatowo/tap/git-why
Or build from source:
git clone https://github.com/alliecatowo/git-why.git
cd git-why
npm ci
npm run build
npm install -g .
The package installs a git-why executable, which Git dispatches as the
subcommand git why. No alias setup needed. More install paths — pinned
versions, a GitHub release tarball, building from source, uninstalling —
are in docs/install.md.
cd your-repo
git why "why do we retry twice before giving up"
The first query downloads a small embedding model (about 32 MB, checksum-verified,
cached under ~/.cache/git-why/models) and indexes the repository's history into
.git/why/; later queries are incremental. Behind a proxy or offline, see
HTTPS_PROXY, GIT_WHY_MODEL_BASE_URL (mirror) and GIT_WHY_OFFLINE in
docs/operations.md. git why status shows whether the
index is current.
Two plugins ship in plugins/:
OpenCode users get opencode/ — an opencode.json with the MCP registration
and an AGENTS.md fragment.
What the skill actually teaches is when not to reach for history. It tells
an agent to use git log -S when it can name the symbol, because that is a
case this tool measurably loses (Hit@10 0.950 against 0.350), and to use code
search rather than history for the current state of the code. A skill that
claims its own tool is always best makes an agent worse at its job.
Any other MCP client can run the server directly: npx -y @alliecatowo/git-why mcp
(or git why mcp once installed). It is also listed in the
MCP registry as
io.github.alliecatowo/git-why.
See docs/plugin.md.
git why server on
Holds the index, the embedding model and the lineage table open between queries. On curl — 30,000 commits — that is 569 ms a query down to 286 ms. Searches use it automatically once it is running.
It can never be the reason a search fails: if no daemon is running, or it is
unreachable, or your index moved under it, the query runs directly instead.
--daemon=direct opts out, --daemon=server requires one. See
docs/daemon.md.
git log --grep only matches words you already know. The reason code
changed usually lives in a commit message, but you rarely remember its exact
wording — you remember the problem, in your own words, months later.
Look again at the first example above: the query is "reconnecting subscribed twice" and the commit is titled "Stop duplicate subscriptions after reconnect." They share almost no vocabulary. That's not a coincidence Git Why is showing off — it's the actual point of a semantic index. It carries the meaning of the change, not just its words, alongside an ordinary keyword index for when you do know the exact term.
Git Why retrieves historical evidence: the commit, the author's actual words, and the relevant diff. Historical commit messages are assertions by their authors, not infallible accounts of intent, and some reasons were never committed at all — Git Why will not manufacture those.
Every number below is written into this file by bench/report.mjs from raw
run data, and CI fails if it drifts — no figure here was typed by hand. Full
methodology, limits, and the negative results are in
docs/report.md.
174 recall questions — you remember a problem but cannot name anything in the
commit that fixed it — derived mechanically from 6 pinned real repositories
(curl, redis, requests, ripgrep, caddy, zod). Every question is verified unanswerable by
keyword search before it enters the set: if git log --grep or git log -S finds the
answer from the question's own words, the case is discarded.
10.2x zg and 23x the best Git-native strategy — and the only approach that answers nearly every question rather than returning an empty set.
When you can name the symbol, use pickaxe search instead. On cross-file causal
questions, git log -S scores Hit@10 0.950 against git why's 0.350.
Semantic search has no advantage over a tool you can hand the exact literal.
That boundary is the honest positioning, and the shipped skill tells agents both halves:
git whygit log -SzgRetrieval quality is not the product. The question is whether an agent answering a real question does it more accurately, or in fewer turns, with the tool than without. Four arms over the same frozen tasks, paired per task, with token counts reconciled against the provider's own accounting database.
Results are mixed across models. At single-digit paired n per model this is descriptive, not significant, and it is reported that way deliberately — the direction is consistent, the magnitude is not established. Full method and per-arm figures in the benchmark report.
Method, per-arm figures and the registered hypothesis: docs/report.md.
Eight optimisations were implemented and measured. One survived.
The one that did: lexical overlap between the question and the commit's own message, reranked over a candidate pool deeper than the result list. Weight chosen on a dev half, evaluated once on the held-out half — +26% MRR and +44% Hit@1 on cases it never saw. Shipped.
The seven that did not: a prose-tuned embedding model, pseudo-relevance feedback, a prose-commit penalty, caller-side query restatement, wider result windows, structural expansion, and phrase fusion. None improved MRR.
What made the difference was not a better idea but a different question. The
seven all asked "does this rank better". The one that worked started by asking
where the right commit actually is — and found that a quarter of the corpus is
retrieved but ranked below 5, which is a reordering problem, while 42% is never
retrieved at all, which is not. See
docs/decisions.md.
The remaining headroom is that 42%: a recall problem in the embedding itself.
That is now measured rather than guessed —
docs/embedding.md compares ten models on a fixed pool.
Transformer embedders score +41% (jina-v2-small) and +64%
(jina-v2-base) MRR over the shipped static one, at 191x and 1287x the
indexing time plus an ONNX runtime. Both are available opt-in; the default
stays fast and dependency-free, because a tool that installs in seconds and
indexes in under a minute should not quietly become one that needs fifteen
hours.
It is also wrong most of the time. Hit@5 of 0.374 means the right commit is
outside the top five on 62.6% of these questions. It beats every alternative on
them and still fails on most. Treat a result as a lead to verify with git show, never as
established fact.
Git Why is ranked retrieval over a semantic index. That's the wrong tool for some jobs, and Git already has the right one:
git log -S and git log -G are exhaustive.
Keyword mode here is ranked, not exhaustive.ripgrep over a checkout, or git grep.git merge-base, git log --ancestry-path and git show.Git Why is for the case where you remember what happened but not what it was called.
ROADMAP.md — pull requests, gh why, wikis, and what
would need measuring before any of it ships.docs/embedding.md — nine embedding models
measured, the +41% one you can opt into, and why the default did not change.docs/daemon.md — the optional daemon: what it holds
warm, why it can never break a search, and its security posture.docs/indexes.md — where indexes live, worktrees,
submodules, monorepos, disk use, and the shared model cache.docs/examples.md — real output on real
repositories, including a case where this is the wrong tool.docs/plugin.md — both plugins, the MCP tools, the
skills, and why there is no hook.docs/decisions.md — what was tried and rejected,
with the measurements. Seven optimisations that did not work.docs/install.md — every install path and
uninstall, including where the index and model cache live on disk.docs/operations.md — the full operational
contract: durability, concurrency, exit codes, history scope, coverage
limits.docs/report.md — the benchmark report this
README's numbers come from.docs/spec.md — the build specification this was
written against. Source comments cite its sections, so it is kept as
provenance rather than as user documentation.mise setup # install dependencies, then doctor
mise check # format, lint, typecheck, protocol hash, unit tests
mise test:integration # real repositories, real storage, real locks
mise test:package # pack, install into a clean prefix, invoke through Git
mise site:build # build the docs/marketing site in site/
mise tasks # everything else, including every benchmark
Numbers in README.md, site/index.md and docs/report.md are written by
bench/report.mjs from raw run data — CI fails if you edit one by hand. The
man page, the site's CLI reference and all three shell completions are checked
against git why -h, which is the only place the flag set is defined.
See docs/contributing.md for module ownership and how
to cut a release.
Finds the Git commits that explain why code is the way it is: semantic and full-text history search.
{ "mcpServers": { "io.github.alliecatowo-git-why": { "command": "npx", "args": [ "-y", "@alliecatowo/[email protected]" ] } }}เครื่องมือ
ยังไม่มีรายการเครื่องมือ เซิร์ฟเวอร์แบบรีโมตจะได้รายการหลังการตรวจสอบสถานะครั้งแรก
FAQ
คัดลอกคอนฟิก stdio สำหรับ Cursor, Claude Desktop, Claude Code หรือ VS Code ได้ในหน้านี้ คอนฟิกนี้ใช้การติดตั้งของผู้เผยแพร่ ไม่ใช่พร็อกซีของ PlugMCP
ระเบียนนี้ไม่ได้ระบุตัวแปรสภาพแวดล้อมที่จำเป็น
Git Why ทำงานแบบโลคัลผ่าน stdio
ตรวจสอบล่าสุดเมื่อ 2026-11-09 Finds the Git commits that explain why code is the way it is: semantic and full-text history search.