How the scanner works

The scanner is the part of Attestly you'll never see, but it's where everything else starts. This page explains what it does, in order.

Phase 1 — fetch

We download the repository tarball at the requested commit SHA via the GitHub REST API. The archive is streamed to a temporary directory inside an isolated worker container. Maximum repo size: 500 MB compressed.

Phase 2 — fingerprint

Before we touch any code, we compute three fingerprints:

• Lockfile hash — pnpm-lock.yaml, package-lock.json, yarn.lock, requirements.txt, go.sum, Cargo.lock, Gemfile.lock.
• Manifest hash — package.json, pyproject.toml, go.mod, Cargo.toml, Gemfile.
• Source hash — a Merkle tree of all *.{ts,tsx,js,jsx,py,go,rs,rb} files.

If all three are unchanged from the previous scan, we skip the AST pass entirely and reuse the prior findings. This is what makes per-PR drift checks fast.

Phase 3 — lockfile sweep

For each lockfile we extract (name, version, license, sha) tuples. This gives us:

• The full transitive dependency graph.
• Every OSS license in the build.
• The exact version of every AI SDK or subprocessor library.

Phase 4 — AST traversal

For TypeScript and JavaScript, we use ts-morph to build a project graph and walk each file. The walker emits import edges (import { OpenAI } from "openai") and call sites (openai.chat.completions.create({ ... })). For Python, we use the AST module; for Go and Rust, we parse import blocks textually.

Phase 5 — detector matching

A detector is a small declarative rule:

{
  key: "openai",
  packages: ["openai", "@azure/openai"],
  imports: [/^openai/, /@azure\/openai/],
  legalEntity: "OpenAI, L.L.C.",
  purpose: "AI inference",
  isAi: true,
  dataCategoriesByDefault: ["communications", "behavioral"],
}

Around 200 such detectors ship in the box. You can add your own — see Custom detectors.

Phase 6 — output

The scan produces a findings table populated with one row per match. Each row carries enough metadata for downstream generators to build accurate documents without ever re-reading your source.