Know what the scan can see.Know where review still matters.

Coverage map

Generated from the built-in behavioral catalog for ruleset 2026.10.27. Each ID links to its exact scope, base severity and confidence, legitimate use, and review action. Package and hash advisories belong to the separate intelligence snapshot.

Supply-chain files by ecosystem

These are static review signals in repository files. An alternate source or build hook can be intentional; repyy does not install, resolve, or execute it.

How repyy improves precision

Rules are interpreted with context so a suspicious token in a test fixture is not treated exactly like the same token in an install hook. Precision changes the review signal; it never turns a scan into proof of safety.

Artifact findings require a download of an upstream run’s artifact followed by a command in the same workflow_run job. Cache-write findings require pull_request_target, issue_comment, or workflow_run with effective write orwrite-only cache mode. They prompt review of upstream trust and job behavior; see GitHub’ssecure-use guidanceandcache access guidance. CI interpolation and secret-egress checks also inspect decoded multiline run blocks one step at a time. A pull_request job on a self-hosted runner is a review signal because the scanner cannot infer repository visibility or fork-approval settings; see GitHub’srunner warning.

Every finding keeps matched locations, occurrence totals, confidence, disposition, and a stable fingerprint. Display controls such as--min-severity, --min-confidence, and --detail change what you see, not the verdict or exit code.

Coverage has a boundary

Default resource limits prevent hostile repositories and archives from exhausting the scanner. When a timeout, limit, permission, clone, archive, or read error reduces coverage, the result is SCAN INCOMPLETE.

Review the coverage warnings before relying on a result. Exit code2 indicates an incomplete target, even if another target completed successfully. Seethe exit-code reference for automation behavior.

Package-manager options such as pip -r/-c are not followed, build configuration is not evaluated, and declared declarations are not fully reconciled with resolved lockfile content; npm lockfile versions are checked as separate package records. Wrapper archive hashes are checked for presence and format, not verified against downloaded bytes. Sibling build.rs detection applies to unpacked repository files.

Raster-image metadata and pixels are not parsed for embedded instructions or scripts. Valid text SVG files are inspected for active content. Binary fonts are never rendered: container/table bounds, selected structural invariants, expansion claims, embedded executable signatures, TrueType program presence, and active OpenType SVG content are checked, with embedded SVG expansion capped at 8 MiB. The scanner does not execute or prove arbitrary glyph or shaping bytecode safe.

PDF and Office checks are static: explicit PDF actions, embedded macro projects, Office external relationships, and DDE fields are reported without opening the document. Encrypted content and arbitrary compressed PDF object streams are not evaluated. VSIX archives are inspected for activation and execution contributions, lifecycle scripts, and bundled executable signatures, but extension behavior is not executed.

Repyy does not inventory deployed runtimes or confirm runtime vulnerability exposure. Patch deployed runtimes independently of a source scan. A checkout cannot establish the contents of a future dependency download: inspect the exact locally available wheel or tarball and review archive-limit warnings. Disabling npm lifecycle scripts does not prevent later import-time execution.

Python response-flow review (FLOW-002) follows simple requests/httpx/urllib calls, assignments and response reads intoexec, eval or compile, retaining source and sink locations. Compilation alone is not execution. API identities and control flow are approximate; arbitrary transforms, cross-function or cross-file flows, downloaded files launched as subprocesses, and equivalent flows in every language require manual review.

Deliberate exclusions

Some signals are outside the scanner’s private, offline boundary or would create misleading accusations.

Explain a rule before acting

Rule explanations are available offline and show the rule’s severity, confidence, disposition, category, matching scope, applicable paths, rationale, legitimate-use context, and recommended action.

Browse the versioned behavioral rule reference or export it with repyy rules catalog --format json.

For package indicators, explanation includes the active snapshot’s advisory source and affected-version context. A package name alone is a review signal; verify the resolved version and artifact before deciding.

Inspect the active intelligence

Built-in behavioral rules and the dated offline intelligence snapshot are separate inputs. The snapshot adds sourced package/version advisories and exact published file hashes.

Every report records the ruleset and intelligence snapshot used, so a finding can be audited later. Readthe intelligence guide for update and rollback behavior.

A practical review workflow