P4 · UNDERSTAND CODEBASES

Code answers that carry a path and a line range, or no answer at all.

LIVEv1.0.0 (tag 099ac8a) · main 24ece08 · CI greenVerified 2026-08-14

Repository question answering built on AST-aware chunks keyed by path::qualname with exact line ranges, a deterministic lexical index where an exact symbol match dominates token overlap, and a catalog-scoped API that takes a repo_id and never a caller filesystem path. Ask it something the catalog cannot support and it returns zero citations rather than a plausible paragraph. Hire this if you want grounding you can click.

Ask create_app on production_rag Read the source

HOSTED · no clone, no key

curl -X POST https://pax-repomind.vercel.app/v1/code/ask -H "Content-Type: application/json" -d '{"question":"Where is create_app defined?","repo_id":"production_rag"}'

Deep link and POST both accept repo_id=production_rag on main 24ece08. Ask something the fixture cannot know and the same endpoint returns zero citations.

LIVE

Every line here is backed by a test, a route, or a file in the repository at v1.0.0 (tag 099ac8a) · main 24ece08 · CI green.

AST chunks keyed by path::qualname with exact line ranges, and a deterministic lexical index where exact symbol match dominates token overlap.
POST /v1/code/ask and POST /v1/code/symbols, plus a GET /ask console whose questions are deep-linkable.
Catalog sandboxing: the API takes a catalog repo_id and never a caller filesystem path; production_rag is a valid catalog id on main 24ece08.
A 14-case mini evaluation and an 8-case production_rag dogfood snapshot, both with a deterministic provider, a null judge, and a $0 bill.
A capture staleness gate: CI records a sha256 per committed PNG and per file that decides what a capture shows, and fails when either drifts.
Hosted console and API on the same fixtures with no key, verified over HTTP on 2026-08-14.
Content-addressed incremental index and GET /v1/catalog at main 24ece08; optional git history returns 503 capability_missing when unavailable.

NOT SHIPPED

The boundary, stated before you find it yourself. Nothing below is presented as built, hidden in a footnote, or described as coming soon.

The hosted instance indexes the committed mini and production_rag fixtures and nothing else. It cannot answer about an arbitrary repository.
The evaluation measures citation plumbing on a fixture. It is not a SOTA claim over real codebases.
No authentication, no rate limiting, and no ingestion of a repository you supply.
The production_rag catalog is a frozen snapshot under fixtures, not a live checkout of the sibling project — it does not update itself when that repository moves.

Capture

One image from the repository at the commit named in the caption.

RepoMind answering a question about its own repository with path and line citations — RepoMind reading its own repository, answering with path:line evidence. Source file

INTERVIEW THIS SYSTEM

Three questions worth asking, and the answers I would give.

Published in advance, because a trade-off I can only defend when nobody has read it first is not a trade-off I understand.

01
Why does the API take a repo_id instead of a path?
A path parameter is a directory traversal waiting for a careless deploy. A catalog id is an allowlist: the service can only answer about repositories someone deliberately indexed. After 4de0ac6 the catalog decides which ids are valid (including production_rag); callers still cannot pass an arbitrary filesystem path.
02
Why does an exact symbol match dominate token overlap rather than being blended into one score?
Identifiers are the query terms that matter most in code and the ones dense or purely lexical scoring dilutes. Ranking exact matches above overlap keeps `create_app` from being outranked by a doc comment that says the word create four times.
03
How do you keep a committed screenshot from quietly becoming a lie?
CI hashes both the PNGs and the template, stylesheet, and console script that decide what they show. Changing the console without regenerating the captures fails the build, so a stale image cannot ship next to a changed UI.

READ THE PRIMARY SOURCES

Everything above is a summary of a file you can open.

The case study explains why the system is shaped this way; SHIP is the LIVE and not-shipped contract this page is derived from.

Code answers that carry a path and a line range, or no answer at all.

LIVE

NOT SHIPPED

Capture

Three questions worth asking, and the answers I would give.

Why does the API take a repo_id instead of a path?

Why does an exact symbol match dominate token overlap rather than being blended into one score?

How do you keep a committed screenshot from quietly becoming a lie?

Everything above is a summary of a file you can open.