opencode AGENTS.md

Repository instructions for the OpenCode project, including rules for branches, commits, pull requests, code structure, and generated files.

In plain words
What is it for?
They guide work such as naming branches, writing commit messages, regenerating the JavaScript software kit, and keeping package dependencies in the intended direction.
Why use it?
They help a coding agent follow the project's local conventions and avoid changing files that are meant to be generated.

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/anomalyco/opencode/agents-md
Clone the repo
git clone --depth 1 https://github.com/anomalyco/opencode

Made for: Codex, OpenCode.

Per session 1,893 This file is loaded in full into every session.
When invoked 1,893 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 $0.01893 $0.01893
Opus 5 $0.00946 $0.00946
Sonnet 5 $0.00379 $0.00379
Haiku 4.5 $0.00189 $0.00189

Measured yesterday against content hash 1c9b877668f7, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

opencode 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 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

AGENTS.md · 162 lines

How it starts

The opening of the file, as written. The whole thing — 162 lines — stays where its author put it; the contents beside it link to each section on GitHub.

  • To regenerate the legacy JavaScript SDK, run ./packages/sdk/js/script/build.ts.
  • After changing the public Protocol or Server HttpApi, run bun run generate from packages/client. Do not edit src/generated or src/generated-effect directly.
  • Keep runtime dependencies directed from Schema to Core and Protocol, then from Core and Protocol to Server. Client runtime code may depend on Schema and Protocol but never Core or Server; sdk-next composes Client, Core, and Server.
  • The default branch in this repo is dev.
  • Local main ref may not exist; use dev or origin/dev for diffs.

Branch Names

Use a short branch name of at most three words, separated by hyphens. Do not use slashes or type prefixes such as feat/ or fix/.

Examples: session-recovery, fix-scroll-state, regenerate-sdk.

Commits and PR Titles

Use conventional commit-style messages and PR titles: type(scope): summary.

Valid types are feat, fix, docs, chore, refactor, and test. Scopes are optional; use the affected package or area when helpful, e.g. core, opencode, tui, app, desktop, sdk, or plugin.

Examples: fix(tui): simplify thinking toggle styling, docs: update contributing guide, chore(sdk): regenerate types.

Style Guide

General Principles

  • Keep things in one function unless composable or reusable
  • Do not extract single-use helpers preemptively. Inline the logic at the call site unless the helper is reused, hides a genuinely complex boundary, or has a clear independent name that improves the caller.
  • Avoid try/catch where possible
  • Avoid using the any type
  • Use Bun APIs when possible, like Bun.file()
  • Rely on type inference when possible; avoid explicit type annotations or interfaces unless necessary for exports or clarity
  • Prefer functional array methods (flatMap, filter, map) over for loops; use type guards on filter to maintain type inference downstream
  • In src/config, follow the existing self-export pattern at the top of the file (for example export * as ConfigAgent from "./agent") when adding a new config module.
  • In Effect generators, bind services to named variables before calling methods. Do not use nested service yields such as yield* (yield* Foo.Service).bar().

Read the full file on GitHub · 162 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 · 162 lines · 1,893 tokens per session scan A 1c9b877668f7

Subscribe to this mod's changes

opencode AGENTS.md is an instructions file published in the GitHub repository anomalyco/opencode (202,755 stars, last pushed today), licensed MIT. It adds 1,893 tokens to every session, about $0.0095 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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