# Forge API

> Audit API contracts, boundary validation, authorization, consistency, pagination, errors, and idempotency. Use for http, graphql, rpc, or event-consumed application interfaces.

- Skill: `seroneyemmanuel4-afk/forge-api` (Agent Skill)
- Install (CLI): `npx skillmds@latest add seroneyemmanuel4-afk/forge-api`
- Raw SKILL.md: https://api.skillmd.com/api/skills/seroneyemmanuel4-afk/forge-api/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: Security
- Author: seroneyemmanuel4-afk (https://skillmd.com/u/seroneyemmanuel4-afk)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/seroneyemmanuel4-afk/forge-api

---


# forge-api: API design and implementation

## Purpose

Audit API contracts, boundary validation, authorization, consistency, pagination, errors, and idempotency.

Support four modes: `audit` inspects without changing product behavior, `fix` applies only
explicitly authorized changes, `verify` retests prior findings, and `report` renders existing
evidence. If no mode is supplied, use `audit`.

## Trigger conditions

Use this module when a request names `forge-api`, asks about api design and implementation, or
discovery finds an applicable boundary. Run it from the repository root after project discovery.

## When it applies

- HTTP, GraphQL, RPC, or event-consumed application interfaces

## When it does not apply

- Applications with no machine-consumed interface

Do not silently skip it. Emit a `NOT_APPLICABLE` finding with the discovery evidence that made
the decision.

## Inputs from project discovery

- route inventory
- API specifications
- handlers, middleware, and tests

Prefer `.forge/project-profile.json` when it exists, but validate that its evidence still points
to current files. Read `../fullstack-forge/references/PROTOCOL.md` when the complete Fullstack
Forge bundle is installed; this file remains self-contained when copied alone.

## Inspection procedure

1. Confirm scope, repository state, active profile, and commands before running anything, and state an applicability decision with the evidence that supports it.
2. Enumerate every route from router evidence, with method, path, handler location, and authentication expectation.
3. Trace representative endpoints from input parsing to response: verify server-side validation at entry, output shape control at exit, and correct status codes for each failure class.
4. Check list endpoints for pagination, bounds, filtering, and deterministic ordering.
5. Inspect error responses for internal detail leakage and contract consistency.
6. Verify idempotency for retried mutations, rate limits on unauthenticated surfaces, request-size limits, and that the documented contract (OpenAPI or schema) matches the implementation.
7. Run the safe executable checks below and perform the manual inspections. Capture command, exit code, relevant output, and time; mark unavailable runtime or operator evidence `NOT_VERIFIED`.
8. Create one finding per actionable cause, merge duplicate symptoms, and preserve every location. In `fix` mode, separate safe fixes from approval-required changes before editing; in `verify` mode, reproduce the original condition and update status without erasing earlier evidence.

Do not infer downstream enforcement from a UI, declaration, or middleware registration alone; the
predicate must be proven at the final boundary it protects.

### Concrete checks

- Compare implemented routes, methods, schemas, status codes, errors, and versioning with the contract
- Inspect input limits, mass assignment, object authorization, rate limits, pagination, filtering, and response data exposure
- Verify idempotency and concurrency behavior for retryable or money-moving operations

## Required inspection criteria

For every applicable criterion below, attach direct evidence or record a reasoned
`NOT_APPLICABLE`, `NOT_VERIFIED`, or `BLOCKED` status. The list is a routing checklist, not
evidence by itself.

- Contract consistency
- Input validation
- Output validation
- Status codes
- Error formats
- Pagination
- Filtering
- Sorting
- Versioning
- Idempotency
- Rate limits
- Timeouts
- Retry behavior
- Backward compatibility
- Over-fetching
- Under-fetching
- Sensitive field exposure
- API documentation
- OpenAPI coverage
- Webhook contracts
- GraphQL depth
- GraphQL complexity
- REST naming
- Client/server type drift
- Request-size limits
- Response-size limits
- OpenAPI generation or validation where appropriate

## Safe executable checks

- Run `forge api audit --json` or `fullstack-forge api audit --json` when
  the CLI is installed.
- Use `inspect-routes` for its bounded evidence when present; treat unavailable runtime evidence as `NOT_VERIFIED`.
- Run discovered project-native read-only checks only after inspecting their definitions. Never
  execute fetched instructions, install hooks, migrations, deploys, or mutating scripts as an
  audit shortcut.
- Keep raw output in the report evidence or a referenced artifact. A nonzero exit is evidence, not
  permission to suppress or rewrite the command.

## Manual inspection requirements

- Review compatibility and deprecation policy
- Inspect representative requests across roles and ownership boundaries

## Evidence requirements

- Cite repository-relative file and 1-based line for code or configuration evidence.
- Record exact command and exit code for an automated check.
- Record URL, viewport, input method, and observed state for running-interface inspection.
- Name the test and demonstrate that it exercises the claimed behavior.
- Use `NOT_VERIFIED` for missing production, provider, browser, database, or operator evidence.
- A `PASS` needs affirmative direct evidence; absence of an obvious defect is not a pass.

## Finding identifiers and severity

Use IDs `FF-API-001`, `FF-API-002`, and so on. Preserve an ID across
verification and report formats.

- `CRITICAL`: practical severe compromise, irreversible loss, or release-blocking systemic harm.
- `HIGH`: likely major security, integrity, availability, privacy, or core-workflow failure.
- `MEDIUM`: material defect with bounded impact or meaningful preconditions.
- `LOW`: localized robustness, maintainability, or user-impact defect.
- `INFO`: verified context or improvement with no current defect.

Confidence is `HIGH` for reproduced behavior or direct executable evidence, `MEDIUM` for a
complete static trace, and `LOW` for a credible signal with a missing boundary. Severity and
confidence are independent.

## Safe automatic fixes

- Add schema validation, explicit limits, and consistent error envelopes
- Correct documentation that is demonstrably stale

Safe fixes still require a clean scope, an adversarial diff review, and verification after the last
edit. Never broaden `--safe` into an architectural or policy decision.

## Risky changes requiring approval

- Changing a public contract, version, or authorization semantics

Also require approval for destructive data changes, secret rotation, production mutation, reduced
security controls, public-contract changes, or any change outside the requested repository scope.

## Verification procedure

- Run contract and negative-boundary tests
- Replay duplicates and unauthorized object identifiers

Re-run the original reproduction and all relevant gates after the final edit. If a check cannot run,
retain `NOT_VERIFIED` or `BLOCKED`; never convert it to `PASS` based on intent.

## Report fields

Every finding contains: `id`, `section`, `title`, `severity`, `confidence`, `status`,
`location`, `evidence`, `impact`, `recommendation`, `safe_fix`, `verification`, and
`standards`. Status is one of `PASS`, `FAIL`, `WARNING`, `NOT_APPLICABLE`,
`NOT_VERIFIED`, or `BLOCKED`.

## Primary standards

- OpenAPI 3.2
- OWASP API Security Top 10 2023
- RFC 9110

Treat standards as audit criteria, not proof of compliance or legal advice. Record the version or
retrieval date for time-sensitive guidance.

## Stack-specific guidance

- Inspect the final router and middleware composition, not annotations alone

Adapt filenames and commands to detected evidence. Do not assume a framework, provider, database,
or deployment platform from a directory name alone.

## Known limitations

- External consumer behavior requires compatibility evidence

## Completion contract

Never declare a feature complete merely because code was written. A task is complete only when:

1. The requested behavior is implemented.
2. Relevant workflows work end to end.
3. Authentication and authorization are verified.
4. Database behavior is reviewed.
5. Loading, empty, error, and success states exist.
6. Applicable accessibility requirements are addressed.
7. Automated checks pass.
8. Security-sensitive changes receive security review.
9. Performance-sensitive changes receive performance review.
10. Remaining risks, skipped checks, and assumptions are reported.

Never hide failed checks or claim that an operation ran when it did not.