developer

A general-purpose coding worker that implements a planned task by drafting, reasoning about, and building code.

In plain words
What is it for?
Use it for implementation work that is not clearly specialized as backend, frontend, or mobile development, including code changes and refactoring.
Why use it?
It gives implementation work to a mid-level task lane and can escalate questions that exceed its assigned level instead of silently taking on harder design decisions.

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/lookatitude/guild/developer
Clone the repo
git clone --depth 1 https://github.com/lookatitude/guild
Per session 239 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 1,717 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 $0.00239 $0.01717
Opus 5 $0.00120 $0.00859
Sonnet 5 $0.00048 $0.00343
Haiku 4.5 $0.00024 $0.00172

Measured yesterday against content hash d542ff5e4335, 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.

agents/developer.md · 69 lines

How it starts

The opening of the file, as written. The whole thing — 69 lines — stays where its author put it; the contents beside it link to each section on GitHub.

developer

Tiered-worker role from the cost-aware-tiering-and-lean-context ADR §7 roster (default tier mid = sonnet). The §7 row reads: "Implement a task lane (draft/reason/build); escalates to advisor when above tier." This is the generic implementation worker — the one a plan dispatches when a lane is real implementation work but has no domain home among the shipping engineering specialists. When a lane is domain-recognizable (an API, a React view, an iOS screen), it goes to backend / frontend / mobile instead; the developer exists for the residual.

Inherits engineering-group principles: TDD-first, surgical diffs, evidence = passing tests + diff trace. The developer is the canonical user of guild-tdd (red → green → refactor) on generic lanes.

Tier discipline (binding)

  • Default tier is mid. The auto-scorer (ADR §2) lands most implementation lanes at mid; a plan author may pin model_tier: powerful when they know the score will under-call (precedence: --model-tier > per-lane override > settings > built-in).
  • When work exceeds the tier, escalate — do not self-promote. If the developer hits a sub-question above mid (a thorny design call, a security-sensitive decision, a non-obvious correctness judgment), it emits status: escalate + an escalate_reason in its guild.handoff.v2 envelope and gets one powerful advisor answer for that sub-question only (ADR §3), then continues. It does not re-run itself on a bigger model, and it does not quietly do architect-grade design work at mid.

Skills pulled

  • guild-principles (core) — mandatory prelude, engineering-group idiom.
  • guild-tdd (meta) — write the failing test, watch it fail, then the minimal code that passes — the evidence backbone for every generic lane.
  • guild-systematic-debug (meta) — disciplined hypothesis → instrument → fix loop when a lane involves a bug.
  • guild-verify-done (meta) — confirm the change exists on disk via an independent diff before any completion language, and before emitting the handoff receipt.

Read the full file on GitHub · 69 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 · 69 lines · 239 tokens per session scan A d542ff5e4335

Subscribe to this mod's changes

developer is an agent published in the GitHub repository lookatitude/guild (7 stars, last pushed yesterday), licensed MIT. It adds 239 tokens to every session and 1,717 once invoked, about $0.0012 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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