Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add kensaurus/cursor-kenji --skill debug-fe-be-integrationgit clone --depth 1 https://github.com/kensaurus/cursor-kenjiWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/kensaurus/cursor-kenji/debug-fe-be-integration)<a href="https://agentmods.dev/skills/kensaurus/cursor-kenji/debug-fe-be-integration"><img src="https://agentmods.dev/badge/skills/kensaurus/cursor-kenji/debug-fe-be-integration/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/kensaurus/cursor-kenji/debug-fe-be-integration"><img src="https://agentmods.dev/badge/skills/kensaurus/cursor-kenji/debug-fe-be-integration.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00061 | $0.03405 |
| Opus 5.5 | $0.00024 | $0.01362 |
| Sonnet 5.5 | $0.00012 | $0.00681 |
| Haiku 4.5 | $0.00006 | $0.00341 |
Grade A, and why
debug-fe-be-integration scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 460 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Frontend-Backend Integration Debug Skill
Degree of freedom: MIXED. Which side is wrong [HIGH freedom];
trace-both-sides probes [LOW freedom — run exactly].
Systematic approach to debugging frontend-backend integration issues by analyzing backend logs, production errors, and source code to identify root causes and fix both sides.
How to reason
- Observe — status, payload, validation error, both logs
- Interpret — FE omitted a field vs BE schema drifted vs auth/CORS
- Classify — missing-param / type / 404 / 401 / 500 / CORS
- Severity — 500 on a write path outranks a cosmetic 422 message
Worked example
Observe: FE
GET /api/reports→ 500; BE logZodError: expected string, received undefinedonyear. Interpret: FE omittedyear; BE schema required it with no default. Classify: missing-param — fix FE call and add a clear BE 422/default. Verify: same request returns 200 with the year bound; both sides updated.
Self-critique before reporting
- Both sides read — FE call and BE schema/logs, not one side guessed
- Contract named — status + payload field, not "they disagree"
- Fix matches class — 404 is not patched as a Zod default
- Right owner — single-layer crash →
debug-error; proactive contract audit →audit-fe-api
Step 0: Auto-Detect Stack
Before debugging, discover the project's architecture.
0a. Detect Frontend Framework
Read package.json and look for:
| Signal | Framework |
|---|---|
next |
Next.js |
nuxt |
Nuxt |
@remix-run/react |
Remix |
@sveltejs/kit |
SvelteKit |
vite + react |
Vite React SPA |
@angular/core |
Angular |
0b. Detect Backend Framework
Glob: **/app/api/**/route.ts → Next.js App Router
Glob: **/pages/api/**/*.ts → Next.js Pages Router
Glob: **/server/api/**/*.ts → Nuxt server
Glob: **/src/routes/**/*.ts → Express/Hono/Fastify
Glob: **/src/app.ts or **/src/index.ts → Node backend entry
Glob: **/main.py or **/app.py → Python backend
Glob: **/main.go → Go backend
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · -2 lines · -5 tokens per session ff4562f67c3a
- 1mo ago First seen · 462 lines · 66 tokens per session scan A 31056c9de48b
debug-fe-be-integration is a skill published in the GitHub repository kensaurus/cursor-kenji (9 stars, last pushed 26d ago), licensed MIT. It adds 61 tokens to every session and 3,405 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-09-03.
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