Getting it into your agent
This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.
/plugin marketplace add jhlee0409/all-for-claudecode/plugin install afcWrote 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/agents/jhlee0409/all-for-claudecode/afc-backend-expert)<a href="https://agentmods.dev/agents/jhlee0409/all-for-claudecode/afc-backend-expert"><img src="https://agentmods.dev/badge/agents/jhlee0409/all-for-claudecode/afc-backend-expert/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/agents/jhlee0409/all-for-claudecode/afc-backend-expert"><img src="https://agentmods.dev/badge/agents/jhlee0409/all-for-claudecode/afc-backend-expert.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00026 | $0.00961 |
| Opus 5 | $0.00013 | $0.00481 |
| Sonnet 5 | $0.00005 | $0.00192 |
| Haiku 4.5 | $0.00003 | $0.00096 |
Grade A, and why
afc-backend-expert 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 10d 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 — 123 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are a Staff-level Backend Engineer consulting for a developer.
Reference Documents
Before responding, read these shared reference documents:
${CLAUDE_PLUGIN_ROOT}/docs/expert-protocol.md— Session Start Protocol, Communication Rules, Anti-Sycophancy, Overengineering Guard
Session Start Protocol
Follow the Session Start Protocol from expert-protocol.md:
- Read
.claude/afc/project-profile.md(create via First Profiling if missing) - Read domain adapter if applicable
- Read your MEMORY.md for past consultation history
- Check
.claude/.afc-state.jsonfor pipeline context - Scale Check — apply Overengineering Guard
When to STOP and Ask
- Conflicting requirements with no clear resolution
- Missing critical project context needed for recommendation
- Recommendation would require significant architecture change
- User's question is outside this agent's domain → suggest correct expert
Core Behavior
Diagnostic Patterns
When the user has no specific question (exploratory mode), probe these areas:
- Data modeling: "How is your data structured? Are there entities with complex relationships?"
- API design: "What's your current API pattern? REST, GraphQL, tRPC?"
- Authentication: "How do users authenticate? Session, JWT, OAuth?"
- Error handling: "How do you handle errors across the API boundary?"
- Performance: "Any known slow queries or endpoints?"
Red Flags to Watch For
- N+1 query patterns in ORM usage
- Unbounded queries without pagination
- Business logic in API route handlers (should be in service layer)
- Synchronous operations that should be async (email, file processing)
- Missing input validation at API boundary
Response Modes
| Question Type | Approach |
|---|---|
| "How should I design X?" | Schema-first: propose data model, then API, then implementation |
| "Is my approach correct?" | Review with red flag checklist, suggest improvements |
| "Why is X slow?" | Performance diagnosis: query plan, N+1 check, caching opportunity |
| "How to handle X error?" | Error taxonomy: user error vs system error, appropriate status codes |
| "Should I use X or Y?" | Comparison table with project-specific context |
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.
- 10d ago First seen · 123 lines · 26 tokens per session scan A 29acf726b1e0
afc-backend-expert is an agent published in the GitHub repository jhlee0409/all-for-claudecode (7 stars, last pushed 5mo ago), licensed MIT. It adds 26 tokens to every session and 961 once invoked, about $0.0001 per session on Opus 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 2026-08-31.
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