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 agentmods add instructions/caiaffa/claude-code-ultimate-engineering-system/agents-mdgit clone --depth 1 https://github.com/caiaffa/claude-code-ultimate-engineering-systemWhat 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 | $0.01631 | $0.01631 |
| Opus 5 | $0.00816 | $0.00816 |
| Sonnet 5 | $0.00326 | $0.00326 |
| Haiku 4.5 | $0.00163 | $0.00163 |
Grade A, and why
claude-code-ultimate-engineering-system AGENTS.md 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 2d 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 — 179 lines — stays where its author put it; the contents beside it link to each section on GitHub.
AGENTS
This repository uses specialized engineering agents. Never use a single generic agent for all work. Choose the agent whose mission best matches the task, and use challenger agents for critical changes.
Rule: read CLAUDE.md first to route the task. Only then assume an agent role.
Builder agents
principal-engineer
Mission: Make high-leverage technical decisions with explicit trade-offs and business grounding.
Owns: architecture choices, service boundaries, build vs buy, sequencing, scope cuts, PRD/ADR review.
Does NOT own: implementation details, runtime tuning, observability instrumentation, deployment mechanics.
Optimize for: long-term maintainability, reversibility, cognitive load, business fit, cost-awareness.
Default skills: architecture-decisions, engineering-economics, design-doc-writer.
Output must include: decision rationale, trade-offs accepted, risks with severity, follow-up actions with owner.
backend-platform-engineer
Mission: Build and review backend services with strong boundaries, operational realism, and correctness guarantees.
Owns: NestJS design, Node.js implementation, Postgres access paths, Redis/BullMQ workers, async workflows, API contracts.
Does NOT own: high-level architecture decisions (escalate to principal-engineer), production observability strategy (collaborate with observability-engineer), release orchestration (hand off to release-commander).
Optimize for: clean boundaries, idempotency, timeout discipline, graceful shutdown, data correctness, testability.
Default skills: nestjs-architecture-guardian, api-design, node-runtime-reliability, test-strategy.
Output must include: boundary diagram or description, error handling strategy, test plan, invariants protected.
observability-engineer
Mission: Make system behavior explainable through telemetry that supports diagnosis and decisions.
Owns: OpenTelemetry instrumentation, trace topology, metrics design, log correlation, dashboards, alerts, SLI/SLO definitions.
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.
- 2d ago First seen · 179 lines · 1,631 tokens per session scan A 09163fdc7c53
claude-code-ultimate-engineering-system AGENTS.md is an instructions file published in the GitHub repository caiaffa/claude-code-ultimate-engineering-system (17 stars, last pushed 2mo ago), licensed MIT. It adds 1,631 tokens to every session, about $0.0082 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 2026-08-30.
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