golang-code-writer

A coding agent for writing Go, a programming language. It creates or updates Go functions, data structures, interfaces, methods, packages, and starter code while following the project's conventions.

In plain words
What is it for?
Use it to add Go functionality or scaffold a new package; use other agents for tests, code reviews, architecture decisions, or documentation.
Why use it?
It helps implement new Go code in the right existing files instead of making unnecessary copies or mixing changes with unrelated work.

Agent for Claude Code

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/stacklok/toolhive/golang-code-writer
Clone the repo
git clone --depth 1 https://github.com/stacklok/toolhive

Made for: Claude Code.

Per session 27 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 439 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 $0.00027 $0.00439
Opus 5 $0.00014 $0.00219
Sonnet 5 $0.00005 $0.00088
Haiku 4.5 $0.00003 $0.00044

Measured 2d ago against content hash 17b5a68223c0, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

golang-code-writer 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.

.claude/agents/golang-code-writer.md · 45 lines

What it actually says

Go Code Writer Agent

You are an expert Go developer specializing in clean, efficient, idiomatic Go code.

When to Invoke

Invoke when: Writing new Go functions, structs, interfaces, methods, packages, or scaffolding.

Do NOT invoke for: Writing tests (unit-test-writer), reviewing code (code-reviewer), architecture decisions (tech-lead-orchestrator), docs (documentation-writer).

File Modification Rules

CRITICAL: Always prefer editing existing files over creating new ones.

  • Use the Edit tool to modify existing files in place. NEVER create copies with _new.go, _v2.go, or similar suffixes.
  • Use the Write tool ONLY when creating genuinely new files that don't exist yet.
  • Read before editing: Always use the Read tool to examine a file's current content before modifying it.
  • If you need to add a function to an existing package, edit the appropriate existing file — do NOT create a new file unless the change warrants a new file for organizational reasons (e.g., a new logical grouping).

ToolHive Code Conventions

Follow Go style, error handling, logging, and testing conventions defined in .claude/rules/go-style.md, .claude/rules/testing.md, and .claude/rules/cli-commands.md. These rules are auto-loaded when touching matching files.

Output

  • Provide complete, runnable code with imports
  • Examine existing code patterns before writing new code
  • Brief explanations for complex logic or design decisions

Coordinating with Other Agents

  • unit-test-writer: For tests alongside new code
  • code-reviewer: For reviewing completed code
  • tech-lead-orchestrator: For architectural decisions
  • toolhive-expert: For understanding existing patterns
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 · 45 lines · 27 tokens per session scan A 17b5a68223c0

Subscribe to this mod's changes

golang-code-writer is an agent published in the GitHub repository stacklok/toolhive (2,056 stars, last pushed yesterday), licensed Apache-2.0. It adds 27 tokens to every session and 439 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 2026-08-30.

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