codeitall — Rust API behavioral oracle
Version-pinned behavioral oracle for Rust package APIs, built for AI coding
agents. Five deterministic tools backed by a Postgres substrate of
66,549,370 pattern_records and 107 successful probe runs across
7 task families (datetime, duration, base64, JSON strict-vs-permissive,
JWT verify, AEAD encrypt/decrypt, constant-time compare).
Hosted, free, no signup: https://api.codeitall.dev
This repository is codeitall's public surface — the API reference, OpenAPI spec, the "For AI Agents" page, and the per-family pages. The ingest/indexer and server source are not redistributed; you consume codeitall by querying the hosted API, not by running it yourself.
What it answers
The differentiator from a docs RAG: the substrate captures runtime behavior (what a function actually does on a canonical input set, observed empirically), not just documentation (what it claims to do). It targets the documentation-vs-runtime gap — yank status, RustSec advisories, deprecation renames, and cross-implementation behavior tables.
Tools
| Tool | Use it for |
|---|---|
answer_api_question | Open-ended Rust API questions; routes deterministically (rule-based, no LLM) and falls back to bge-m3 cosine retrieval. |
signature_search | You know the signature shape (fn(&str) -> Result<Vec<u8>, _>); get ranked candidate functions + crate, downloads, yank status. |
behavior_lookup | A specific (crate, fn_name); get the probe-observation table verbatim — each row (input, outcome=ok|err|panic, value_or_error). |
compare_implementations | A task category (e.g. "base64 crates"); get the side-by-side cross-implementation behavior table. |
find_modern_equivalent | A suspected-deprecated call; get the current canonical alternative + yank/advisory rows. |
Determinism contract
No generative LLM sits between a request and its response. Every response is SQL + deterministic templating; the only model in the hot path is bge-m3, a deterministic text→vector embedder used for the cosine fallback (same input → same vector → same hits). This is a regression-pinned invariant.
Quickstart
# Mint a free anonymous key (no email, no signup):
curl -sX POST https://api.codeitall.dev/v1/keys \
-H 'content-type: application/json' -d '{}'
# Ask a question (HTTP REST):
curl -sX POST https://api.codeitall.dev/v1/answer_api_question \
-H 'content-type: application/json' \
-d '{"question":"how do I parse a duration string in rust"}'
GET aliases exist for every tool (browse-only clients); signature_search
also accepts a shape_b64 (base64url) parameter so URL re-encoding can't
mangle type-signature characters.
Access modes
- MCP — SSE/HTTP at
https://api.codeitall.dev/mcp(Bearer key), or stdio for self-hosters. - HTTP REST —
POST/GET /v1/<tool>. - OpenAPI 3.1 —
openapi.json(live:https://api.codeitall.dev/openapi.json).
Docs in this repo
for-ai-agents.html— positioning, tool list, key snippet (live:https://api.codeitall.dev/for-ai-agents.html).api-reference.html/api-reference.md— generated tool reference + scope/coverage.agents/— one page per probe family.
Cost & limits
Free. Per-IP key issuance cap (10/day) and per-key quota (10,000/day). No paid tier, no email capture, no signup.