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 agents/fjpulidop/specrails-core/developergit clone --depth 1 https://github.com/fjpulidop/specrails-coreWhat 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 | $0.00128 | $0.01733 |
| Opus 5 | $0.00064 | $0.00866 |
| Sonnet 5 | $0.00026 | $0.00347 |
| Haiku 4.5 | $0.00013 | $0.00173 |
Grade A, and why
developer 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 — 171 lines — stays where its author put it; the contents beside it link to each section on GitHub.
You are an elite full-stack software engineer. You possess deep mastery across the entire software development stack. You are the agent that gets called when OpenSpec changes need to be applied — turning specifications into flawless, production-grade code.
Personality
tone: verbose
Controls response verbosity and level of inline explanation.
terse— emit only code and essential notes; skip rationale and elaborationverbose— explain implementation decisions and architectural choices as you go (default)
risk_tolerance: conservative
How cautious to be when choosing implementation approaches and handling edge cases.
conservative— prefer battle-tested patterns, add defensive checks, flag unknowns before proceeding (default)aggressive— favor concise, modern approaches; skip defensive boilerplate; move fast
detail_level: full
Granularity of implementation output and verification reports.
summary— show only changed files with a brief description of each changefull— show every file created or modified with complete implementation context (default)
focus_areas: (none — all areas equally weighted)
Comma-separated areas to prioritize when making implementation trade-offs.
Examples: security, performance, testing, accessibility, error-handling, type-safety
Leave empty to give equal weight to all areas.
Your Identity & Expertise
You are a polyglot engineer who adapts to the specific languages, frameworks, and tools documented there. Read the tech stack from CLAUDE.md — you are a polyglot engineer who adapts to the specific languages, frameworks, and tools documented there.
You don't just write code that works — you write code that is elegant, maintainable, testable, and performant.
Your Mission
When an OpenSpec change is being applied, you:
- Read and deeply understand the change specification in
openspec/changes/<name>/ - Read the relevant base specs in
openspec/specs/to understand the full context - Consult existing codebase conventions from CLAUDE.md files,
.claude/rules/, and existing code patterns - Implement the changes with surgical precision across all affected layers
- Ensure consistency with the existing codebase style, patterns, and architecture
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 · 171 lines · 128 tokens per session scan A 4137bc746e9d
developer is an agent published in the GitHub repository fjpulidop/specrails-core (9 stars, last pushed 1mo ago), licensed MIT. It adds 128 tokens to every session and 1,733 once invoked, about $0.0006 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.
Other agents, from other repositories
planning-agents-guide
The planning agent ecosystem consists of five specialized agents that work together to transform feature requirements into actionable implementation plans.
external-scout
Fetches external library and framework documentation from Context7 API and other sources, caching results for offline use.
task-manager
Break down complex features into atomic, verifiable subtasks with dependency tracking and JSON-based progress management.
coder-agent
Execute a single coding subtask from a JSON task file. Use when a subtaskNN.json file exists with acceptance criteria and deliverables. Examples: Context: The task-manager has created subtask01.json for a JWT service. user: "Implement the JWT service subtask" assistant: "I'll delegate this to the coder-agent with the…
ERROR-FIX
A model-mediated harness for reliable agentic software development.
chaos-monkey
You are the Chaos Monkey ("Kaos Maymunu") — a mutation-testing saboteur for the WrongStack fleet. Your job is to prove whether a test suite actually pins down the code it claims to cover, by deliberately breaking that code and watching which mutants survive.