Frontend Backend Flow Test

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name: frontend-backend-flow-test description: Audit-first frontend-backend contract analyzer for static API compatibility checks. Compare frontend request behavior with backend endpoint contracts, DTO hints, query/body/auth expectations, and produce actionable mismatch reports. Supports Spring-style Java/Kotlin backends, baseline Node/Express route extraction, and baseline PHP/Laravel route extraction. Use when validating whether web/mobile/admin clients still match backend APIs after refactors, release prep, or regression review. Live API verification is secondary and limited; do not use this skill as a production-safe write tester or full E2E framework.

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Frontend-Backend Flow Test

Use this skill as an audit-first contract checker.

Primary purpose:

extract frontend API calls

extract backend endpoint contracts

compare method/path/query/body/auth hints

generate actionable audit reports

Secondary purpose:

generate limited experimental live-check helpers only when static audit is insufficient and the environment is explicitly safe

Default workflow

1. Run static audit first with scripts/audit_contracts.py 2. Read the generated Markdown and JSON reports 3. Fix high-severity contract mismatches before considering live checks 4. Use live verification only for narrow follow-up validation in dev/staging

Core command

python3 scripts/audit_contracts.py \
  --frontend /path/to/frontend \
  --backend /path/to/backend \
  --output-dir ./out/audit \
  --exclude .dart_tool,coverage \
  --format both \
  --fail-on high

What this skill is good at

finding missing backend endpoints referenced by frontend code

detecting HTTP method drift

detecting path drift and base-path mismatches

comparing query/body/auth hints between frontend and backend

summarizing likely breakpoints before release or QA

auditing multiple surfaces against the same backend

What this skill is not

not a real API regression framework

not a replacement for workspace QA tests

not a full E2E test framework

not a production-safe write tester

not guaranteed rollback tooling

not comprehensive support for arbitrary frameworks/languages

not a replacement for manual QA or runtime observability

Current extraction coverage

Frontend

Axios-style calls

fetch(...)

some Dart/Dio direct calls and wrapper patterns

basic alias/baseURL/header inference

Backend

Spring controller mappings

Java/Kotlin DTO field hints

selected Spring Security route hints

Express app/router mappings

same-file Express router mount prefix inference

Laravel route file mappings

Laravel resource/apiResource expansion

basic request body / query / multipart inference

Reporting expectations

Expect findings such as:

missing-backend-endpoint

method-mismatch

path-mismatch

query-hint-mismatch

body-hint-mismatch

response-hint-mismatch

auth-hint-mismatch

backend-only-endpoint

Treat the report as a prioritized contract-audit output, not as runtime proof that a user flow succeeds.

References

Read these only when needed:

references/MVP-SPEC.md for the audit-first product boundary

references/AUDIT-SCOPE.md for supported extraction scope and interpretation guidance

references/LIMITATIONS.md for known blind spots and confidence cautions

references/EXAMPLES.md for audit command examples

references/LIVE-MODE.md only when live verification is explicitly required