opencode

opencode is a skill for Claude Code, Codex from laude-institute/headlong. It costs 25 tokens per session (322 once invoked), scanned A, original, Apache-2.0.

A workflow for giving a limited coding task to OpenCode, an external coding agent, then reviewing its proposed changes and verification results. It keeps the candidate and review records without merging or deploying the work.

In plain words
What is it for?
It is for assigning bounded repository changes, running a project-specific verification command, reviewing the resulting patch, and preparing acceptable work for human review.
Why use it?
It adds an independent check to agent-written code instead of treating a passing test as proof that the whole requirement was met. It preserves earlier attempts when revisions are needed.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions OpenCode.

Good fit It is for assigning bounded repository changes, running a project-specific verification command, reviewing the resulting patch, and preparing acceptable work for human review.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/laude-institute/headlong/skill
About the project

Headlong is a Bash-based agent microharness for running language-model agents in persistent, self-directed loops. People use it to create agents that maintain ongoing interests and projects, interact through shell commands, and share one stream of conversations across a team and chat services.

laude-institute/headlong · 1,227 stars · on GitHub · headlong.ai

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.

Any agent
npx skills add laude-institute/headlong --skill skill
Clone the repo
git clone --depth 1 https://github.com/laude-institute/headlong

Made for: Claude Code, Codex.

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

README.md
[![agentmods](https://agentmods.dev/badge/skills/laude-institute/headlong/skill/github.svg)](https://agentmods.dev/skills/laude-institute/headlong/skill)
Your own site
<a href="https://agentmods.dev/skills/laude-institute/headlong/skill"><img src="https://agentmods.dev/badge/skills/laude-institute/headlong/skill/github.svg" alt="Measured on agentmods" height="20"></a>

Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.

agentmods 80×15 button for opencode

Your own site · 80×15
<a href="https://agentmods.dev/skills/laude-institute/headlong/skill"><img src="https://agentmods.dev/badge/skills/laude-institute/headlong/skill.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 25 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 322 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 $0.00025 $0.00322
Opus 5.5 $0.00010 $0.00129
Sonnet 5.5 $0.00005 $0.00064
Haiku 4.5 $0.00003 $0.00032

Measured 25d ago against content hash 39166b169071, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

opencode 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 25d 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.

contrib/opencode/skill/SKILL.md · 34 lines

What it actually says

Use this capability during the existing act action for a bounded coding task with a meaningful independent verification command. Write the requirements to a task file and invoke the installed wrapper:

"$IDENTITY_DIR/extensions/opencode/bin/coding-agent" \
  --repo /absolute/path/to/repository --task-file /absolute/path/to/task.md \
  --verify 'project-specific-check' --out /absolute/path/to/new-artifacts

Inspect the status, candidate commit, patch, verification output, and child trajectory reference. A passing test does not establish that the requirements are satisfied: review the diff and behavior the test did not cover. Record rejection and concrete feedback in the trajectory when inadequate. For a revision, use a fresh output directory and retain earlier candidate/review references. Leave satisfactory candidates ready for human review with accepted:false. Enablement does not authorize merge, push, deployment, or acceptance.

The operator may disable this skill between wakes. A remembered absolute path will then reject new calls; do not bypass that control. Worktrees and model permissions are not an OS sandbox. See the installed package's README for runtime configuration and retained artifact cleanup.

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. 25d ago First seen · 34 lines · 25 tokens per session scan A 39166b169071

Subscribe to this mod's changes

opencode is a skill published in the GitHub repository laude-institute/headlong (1,227 stars, last pushed yesterday), licensed Apache-2.0. It adds 25 tokens to every session and 322 once invoked, about $0.0001 per session on Opus 5.5. 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 2026-09-29.

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