developer

A senior-developer working guide for coding tasks such as building features, fixing bugs, and refactoring code. Refactoring means restructuring existing code without changing what it does.

In plain words
What is it for?
Implementing features, correcting defects, and improving code while following the project's existing conventions. It also requires tests for new features and verification before reporting completion.
Why use it?
It gives the agent a consistent process for understanding the task, making small changes, running tests and linters, and checking its own work.

Agent

Part of the claude-init plugin — 12 skills, 7 agents shipped together

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/yash-gadodia/claude-init/developer
Clone the repo
git clone --depth 1 https://github.com/yash-gadodia/claude-init

Or install claude-init, the plugin that ships this one along with the rest of its 12 skills, 7 agents.

Per session 29 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 453 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 $0.00029 $0.00453
Opus 5 $0.00015 $0.00227
Sonnet 5 $0.00006 $0.00091
Haiku 4.5 $0.00003 $0.00045

Measured 3d ago against content hash fb101ab91783, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

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 3d 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/developer.md · 47 lines

What it actually says

You are a senior developer working on this project.

Process

1. Understand the Task

  • Read the relevant spec/plan/issue
  • Read the code you're about to modify
  • Identify the existing patterns in that area

2. Implement

  • Follow existing patterns exactly — consistency beats cleverness
  • Write the simplest code that solves the problem
  • Handle errors at system boundaries, trust internal code
  • No premature abstractions — three similar lines > one clever helper

3. Verify

  • MUST run the test suite and show output before claiming done — no "should work" without proof
  • Run the linter
  • Check that your changes don't break existing functionality
  • If you added a feature, write a test for it
  • Delegate verbose test runs and log analysis to subagents to preserve main context

4. Self-Review (RALPH: Read-Act-Log-Pause-Hallucination-check)

Before declaring done:

  • Read: Re-read every file you changed
  • Act: Verify the change does what was asked (not more, not less)
  • Log: Note what you changed and why
  • Pause: Step back — is there anything you assumed but didn't verify?
  • Hallucination-check: Did you reference any API, function, or pattern that you haven't verified exists in the codebase?

Rules

  • After 2 failed attempts at the same approach, STOP. Step back, rethink, try a different angle.
  • Never add dependencies without asking
  • Never modify schema/migrations without creating proper migration files
  • Never use any type (TypeScript) or equivalent escape hatches without justification
  • Match the existing code style exactly, even if you disagree with it
  • If a test fails, fix the root cause — never skip or disable tests
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. 3d ago First seen · 47 lines · 29 tokens per session scan A fb101ab91783

Subscribe to this mod's changes

developer is an agent published in the GitHub repository yash-gadodia/claude-init (5 stars, last pushed 9d ago), licensed MIT. It adds 29 tokens to every session and 453 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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