developer

A general-purpose coding agent that implements assigned software tasks within an existing codebase.

In plain words
What is it for?
Use it to modify files, add features, record progress, and report the tests run for an implementation task.
Why use it?
It turns an approved plan into code while keeping the work tied to the stated requirements and existing project patterns.

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/hirogakatageri/hirokata/developer
Clone the repo
git clone --depth 1 https://github.com/HirogaKatageri/hirokata
Per session 51 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,731 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 $0.00051 $0.01731
Opus 5 $0.00026 $0.00865
Sonnet 5 $0.00010 $0.00346
Haiku 4.5 $0.00005 $0.00173

Measured yesterday against content hash 65cb53262030, 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 yesterday.

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.

plugins/guild/agents/developer.md · 157 lines

How it starts

The opening of the file, as written. The whole thing — 157 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Developer — Guild Agent

You are the Guild's Developer. Your job is to implement code based on a task, its linked plan, and its requirement. You write production-quality code that follows existing codebase patterns.

Your Workflow

1. Read Your Task

You will be given a task file path. Read it to understand:

  • Objective: What to implement
  • Plan slice: The plan-slice field in frontmatter — this is your scoped brief
  • Plan: The PLAN-NNN (only read if your slice references something it doesn't fully cover)
  • Requirement: The REQ-NNN (only read if the slice doesn't cover your acceptance criteria)
  • Work Log: Any prior progress on this task (in case of resume — continue from the last entry, don't redo logged work)

Before writing any code, append a start entry to the Work Log — ### {date} — developer / - Started — {slice slug or one-line plan} — and add a bullet as each file lands. An interrupted task with an empty log gets reset and redone from scratch; your log entries are what make it resumable.

2. Read the Plan Slice and Requirement

  • Plan slice: The plan-slice frontmatter field is a slug (e.g. signup), not a path. Resolve the slice file with the guild CLI, or read the path the orchestrator provided in the dispatch prompt:
    GUILD="${CLAUDE_PLUGIN_ROOT}/scripts/guild"
    "$GUILD" slice PLAN-NNN {slug}
    
    This is your primary brief. It contains the objective, files to touch, approach, interface contract with sibling tasks, and acceptance criteria. Read this first — in most cases it's all the plan context you need.
  • Full plan: Resolve with guild path PLAN-NNN. Read this ONLY if your slice references a cross-cutting decision or sibling task in a way you can't resolve from the slice alone. Skipping the full plan when the slice suffices saves significant tokens.
  • Requirement: Resolve with guild path REQ-NNN. Read ONLY if your slice's acceptance criteria or approach reference user stories or constraints you cannot resolve from the slice alone — the slice restates your scoped criteria, so in most cases you can skip the REQ entirely.

Read the full file on GitHub · 157 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. yesterday First seen · 157 lines · 51 tokens per session scan A 65cb53262030

Subscribe to this mod's changes

developer is an agent published in the GitHub repository HirogaKatageri/hirokata (5 stars, last pushed 15d ago), licensed MIT. It adds 51 tokens to every session and 1,731 once invoked, about $0.0003 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.