goa-ai AGENTS.md

Repository instructions for goa-ai, covering its Go coding style, project structure, planning rules, error handling, and review practices.

In plain words
What is it for?
Use them when working in the goa-ai repository, especially when planning edits, searching before changing files, simplifying designs, or checking automated review findings.
Why use it?
They give a coding agent clear project-specific expectations before it changes code or prepares a merge request.

Instructions file for CodexOpenCode

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 instructions/goadesign/goa-ai/agents-md
Clone the repo
git clone --depth 1 https://github.com/goadesign/goa-ai

Made for: Codex, OpenCode.

Per session 2,892 This file is loaded in full into every session.
When invoked 2,892 The same file — it is already loaded in full.
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 $0.02892 $0.02892
Opus 5 $0.01446 $0.01446
Sonnet 5 $0.00578 $0.00578
Haiku 4.5 $0.00289 $0.00289

Measured 2d ago against content hash c299793285ed, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

goa-ai AGENTS.md 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.

AGENTS.md · 186 lines

How it starts

The opening of the file, as written. The whole thing — 186 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You are an agentic systems engineer. Optimize for elegance, strong contracts, conceptual correctness, and less code. Prefer deleting bad abstractions to preserving them. Do not add fallbacks, coercions, or defensive code that hides bugs.

Repository Guidelines

Core Operating Rules

  • Plan before acting: for <=2 files, state a brief plan then implement; for >=3 files, write a step-by-step plan first.
  • Read before editing. Search instead of guessing.
  • Before merging a pull request, address every applicable automated review finding. Verify each finding against the current diff, fix confirmed issues, and explicitly resolve or explain findings that do not require a change.
  • Fix root causes, not local workarounds.
  • Prefer the simplest design that satisfies the contract. Reduce surface area, delete dead code, and avoid new concepts unless they clearly pay for themselves.
  • Be concise in progress updates and summaries.
  • Keep one canonical implementation and one source of truth per concept. Delete unused code and commented-out code.
  • Before adding an exported type, shared interface, callback shape, wire record, or package dependency, trace the complete producer-to-consumer flow and separate the unavoidable domain concept from implementation plumbing. List which facts the DSL and generator already know, compare private, raw, generated, and public representations, and choose the smallest public contract. Do not export a type merely to avoid an import cycle, simplify one call site, or pass parsed data to code that can privately own decoding. Complete this public-surface and generation-first review before editing; successful tests and a later cleanup pass do not make unnecessary API surface acceptable.
  • Validate only at boundaries: HTTP/gRPC handlers, event consumers, DB results, third-party APIs, ctx.Value(), type assertions, and required map lookups. Inside the codebase, trust Goa and construction-time invariants.
  • Fail fast on invariant violations. Do not add nil/empty guards, fallback behavior, back-compat fishing logic, or "should not happen" branches for values guaranteed by contracts.
  • Do not perform best-effort coercions in runtime/codegen. If a payload, result, or type assertion does not match the contract, return a precise error instead of silently remapping it.
  • Configuration belongs in constructors, not environment-variable reads in core logic.
  • Keep docs in sync with behavior:
    • User-facing goa-ai DSL, runtime, or codegen changes must update content/en/docs/2-goa-ai/ and translated pages when applicable.
    • Update README.md and DESIGN.md when behavior changes.

Read the full file on GitHub · 186 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 · 186 lines · 2,892 tokens per session scan A c299793285ed

Subscribe to this mod's changes

goa-ai AGENTS.md is an instructions file published in the GitHub repository goadesign/goa-ai (8 stars, last pushed 3d ago), licensed MIT. It adds 2,892 tokens to every session, about $0.0145 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.

Related

Other instructions, from other repositories