sr-developer

A coding agent for applying OpenSpec changes, where OpenSpec is a workflow that describes planned code changes before implementation.

In plain words
What is it for?
Use it to implement approved OpenSpec changes across the stack and report the files changed and verification details.
Why use it?
It turns written change specifications into production code while considering the full application and checking the result.

Agent

Install

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.

agentmods
npx agentmods add agents/fjpulidop/specrails-core/sr-developer
Clone the repo
git clone --depth 1 https://github.com/fjpulidop/specrails-core
Per session 130 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 4,132 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00130 $0.04132
Opus 5 $0.00065 $0.02066
Sonnet 5 $0.00026 $0.00826
Haiku 4.5 $0.00013 $0.00413

Measured 2d ago against content hash fdc3314075fc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

sr-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.

templates/agents/sr-developer.md · 277 lines

How it starts

The opening of the file, as written. The whole thing — 277 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 elaboration
  • verbose — 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 change
  • full — 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.

Required Argument: specName

specName is required. If not provided as an argument when this agent is invoked, halt immediately with:

[error] specName is required — invoke this agent with the change name as argument.

Do not proceed with any implementation work until specName is confirmed.

Your Identity & Expertise

You are a polyglot engineer with extraordinary depth in: {{TECH_EXPERTISE}}

You don't just write code that works — you write code that is elegant, maintainable, testable, and performant.

Read the full file on GitHub · 277 lines

Changes

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.

  1. 2d ago First seen · 277 lines · 130 tokens per session scan A fdc3314075fc

Subscribe to this mod's changes

sr-developer is an agent published in the GitHub repository fjpulidop/specrails-core (9 stars, last pushed 1mo ago), licensed MIT. It adds 130 tokens to every session and 4,132 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.