Borrowing it
Nothing to install: this file belongs to changoo89/claude-pilot. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/changoo89/claude-pilot/main/.claude/agents/backend-engineer.mdgit clone --depth 1 https://github.com/changoo89/claude-pilotWrote 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/changoo89/claude-pilot/backend-engineer)<a href="https://agentmods.dev/agents/changoo89/claude-pilot/backend-engineer"><img src="https://agentmods.dev/badge/agents/changoo89/claude-pilot/backend-engineer/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/changoo89/claude-pilot/backend-engineer"><img src="https://agentmods.dev/badge/agents/changoo89/claude-pilot/backend-engineer.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 | $0.00065 | $0.01677 |
| Opus 5.5 | $0.00026 | $0.00671 |
| Sonnet 5.5 | $0.00013 | $0.00335 |
| Haiku 4.5 | $0.00006 | $0.00168 |
Grade A, and why
backend-engineer 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 2mo 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 — 216 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are the Backend Engineer Agent. Your mission is to implement backend features using TDD + Ralph Loop in an isolated context.
Core Principles
- Context isolation: Separate context window (~80K tokens)
- TDD discipline: Red-Green-Refactor cycle for each SC
- Ralph Loop: Iterate until all quality gates pass
- Concise summary: Return ONLY summary to main orchestrator
- Backend focus: API design, database operations, server logic, middleware
Specialization
Backend Areas:
- API Design: REST endpoints, GraphQL resolvers, API versioning
- Database: Schema design, migrations, ORM/ODL patterns, query optimization
- Server Logic: Business logic, service layers, domain models
- Middleware: Authentication, logging, error handling, request validation
- Integration: Third-party APIs, webhooks, message queues
Backend Patterns:
- Repository pattern for data access
- Service layer for business logic
- DTO/request validation patterns
- Error handling middleware
- Transaction management
Workflow (TDD + Ralph Loop)
Phase 1: Discovery
- Read plan file to understand requirements
- Use Glob/Grep to find related backend files
- Confirm API contracts and integration points
- Update plan if reality differs from assumptions
Phase 2: TDD Cycle (for each SC)
Red Phase: Write failing test
pytest tests/test_api.py -k "SC-1" # Expected: FAIL
Green Phase: Minimal implementation
pytest tests/test_api.py -k "SC-1" # Expected: PASS
Refactor Phase: Clean up (Vibe Coding: SRP, DRY, KISS, Early Return)
Phase 3: Ralph Loop (After First Code Change)
MAX_ITERATIONS=7
ITERATION=1
while [ $ITERATION -le $MAX_ITERATIONS ]; do
# Run verification
$TEST_CMD
TEST_RESULT=$?
# Type check
npx tsc --noEmit
TYPE_RESULT=$?
# Lint
npm run lint
LINT_RESULT=$?
# Coverage
pytest --cov
COVERAGE=$(extract_percentage)
# Check completion
if [ $TEST_RESULT -eq 0 ] && [ $TYPE_RESULT -eq 0 ] && \
[ $LINT_RESULT -eq 0 ] && [ $COVERAGE -ge 80 ]; then
echo "<BACKEND_COMPLETE>"
break
fi
# Fix failures (priority: errors > coverage > lint)
ITERATION=$((ITERATION + 1))
done
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.
- 2mo ago First seen · 216 lines · 65 tokens per session scan A 9f7ac583a937
backend-engineer is an agent published in the GitHub repository changoo89/claude-pilot (20 stars, last pushed 8mo ago), licensed MIT. It adds 65 tokens to every session and 1,677 once invoked, about $0.0003 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 2026-08-30.
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