opencode: Instructions file for Codex

AGENTS.md

opencode AGENTS.md is an instructions file for Codex, OpenCode from magnusoverli/opencode. It costs 670 tokens per session, scanned A, original, Unlicense.

Repository instructions for developing the OpenCode Home Assistant app, covering the development environment, standard tasks, build process, runtime checks, and diagnostics.

In plain words
What is it for?
Use them when developing, building, installing, starting, testing, or diagnosing this repository's Home Assistant app.
Why use it?
They give coding agents the project-specific rules needed to work in the correct environment and verify runtime changes.

Instructions file for CodexOpenCode

Written for Codex and OpenCode: the file is AGENTS.md.

This is magnusoverli/opencode's own configuration. It tells Codex and OpenCode how to work on opencode itself, so it is not a mod to install elsewhere. Copy it as a starting point and replace the rules that are about this project. Everything opencode configures →

Reuse

Borrowing it

Nothing to install: this file belongs to magnusoverli/opencode. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.

Copy the file
curl -O https://raw.githubusercontent.com/magnusoverli/opencode/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/magnusoverli/opencode

Made for: Codex, OpenCode.

Wrote this? Show the measurements

A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.

agentmods badge for opencode AGENTS.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/magnusoverli/opencode/agents-md.svg)](https://agentmods.dev/instructions/magnusoverli/opencode/agents-md)
Your own site
<a href="https://agentmods.dev/instructions/magnusoverli/opencode/agents-md"><img src="https://agentmods.dev/badge/instructions/magnusoverli/opencode/agents-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 670 This file is loaded in full into every session.
When invoked 670 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 5.1 $0.00670 $0.00670
Opus 5 $0.00335 $0.00335
Sonnet 5 $0.00134 $0.00134
Haiku 4.5 $0.00067 $0.00067

Measured 2d ago against content hash 891f72fcdca4, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, 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 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 · 49 lines

How it starts

The opening of the file, as written. The whole thing — 49 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Repository Agent Guidance

Default Development Environment

The official Home Assistant Apps devcontainer is the default environment for developing this repository. It runs real Supervisor and Home Assistant containers and exposes this repository as local apps.

  • Start runtime-affecting work from .devcontainer/devcontainer.json. Do not install or approximate Supervisor directly on the host.
  • Use the canonical VS Code task sequence in .vscode/tasks.json: Start Home Assistant, Install App, then Start App for the first run. Use Rebuild and Start App while iterating, Run App Acceptance after runtime/lifecycle changes, and Show App Logs for diagnostics.
  • Select ha_opencode for stable or ha_opencode_beta for beta. Do not infer a channel from the current branch; both channels live on main.
  • Build working-tree images with scripts/devcontainer-build-app.sh, as the tasks do. Do not use ha apps rebuild --force: because production config.yaml declares image:, Supervisor can re-pull the published image instead of building the checkout.
  • Treat successful Supervisor install/start, s6 service state, Home Assistant Core Ingress routing, and scripts/devcontainer-acceptance.sh results from this environment as local lifecycle evidence. The devcontainer is not HAOS and does not prove host-level HAOS behavior.
  • Host-side reads, edits, and focused static/unit tests are acceptable when they do not need the app runtime. Do not substitute host Docker or local QEMU for the devcontainer when validating Supervisor/s6 behavior.
  • Arm64 acceptance runs on GitHub's native ARM runner. Local emulated arm64 builds are optional diagnostics and never a release gate.
  • If the devcontainer cannot run, report that limitation and the unverified lifecycle behavior instead of silently using a lower-fidelity substitute.

Verification Budget

Use the smallest verification step that provides direct evidence for the change. Testing should support development rather than repeatedly delay it.

Read the full file on GitHub · 49 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 · 49 lines · 670 tokens per session scan A 891f72fcdca4

Subscribe to this mod's changes

opencode AGENTS.md is an instructions file published in the GitHub repository magnusoverli/opencode (375 stars, last pushed 5d ago), licensed Unlicense. It adds 670 tokens to every session, about $0.0034 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 2026-09-03.

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