opencode-harness

opencode-harness is a skill for Claude Code from Human-Frontier-Labs-Inc/human-frontier-labs-marketplace. It costs 143 tokens per session (970 once invoked), scanned C, original, no licence file.

A setup for the OpenCode “zen” model harness, which lets a coding agent send different kinds of work to different models while Claude coordinates and checks the results.

In plain words
What is it for?
Integrating OpenCode, connecting models for fast work, difficult reasoning, or code generation, and routing agent tasks by capability.
Why use it?
It helps reduce use of Claude’s token budget by assigning suitable work to cheaper models.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the opencode-harness plugin — 1 skill, 1 command shipped together

Good fit Integrating OpenCode, connecting models for fast work, difficult reasoning, or code generation, and routing agent tasks by capability.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness
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 Human-Frontier-Labs-Inc/human-frontier-labs-marketplace --skill opencode-harness
Clone the repo
git clone --depth 1 https://github.com/Human-Frontier-Labs-Inc/human-frontier-labs-marketplace

Made for: Claude Code.

Or install opencode-harness, the plugin that ships this one along with the rest of its 1 skill, 1 command.

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-harness

README.md
[![agentmods](https://agentmods.dev/badge/skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness/github.svg)](https://agentmods.dev/skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness)
Your own site
<a href="https://agentmods.dev/skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness"><img src="https://agentmods.dev/badge/skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness/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-harness

Your own site · 80×15
<a href="https://agentmods.dev/skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness"><img src="https://agentmods.dev/badge/skills/human-frontier-labs-inc/human-frontier-labs-marketplace/opencode-harness.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 143 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 970 The whole file, excluding the scripts and references it only reads on demand.
Security scan C 2 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin unknown 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 $0.00143 $0.00970
Opus 5.5 $0.00057 $0.00388
Sonnet 5.5 $0.00029 $0.00194
Haiku 4.5 $0.00014 $0.00097

Measured 2mo ago against content hash 355a9abe7cca, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade C, and why

opencode-harness scanned grade C with 2 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 2mo ago.

The scan reads SKILL.md. This mod also ships 2 executable files (scripts/ask.sh, scripts/setup.sh), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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.

Downloads and executes remote codehighSupply chain

curl | sh runs whatever the server returns today, which is not necessarily what it returned when this was reviewed.

- **opencode CLI** — `curl -fsSL https://opencode.ai/install | bash`.

Makes network callslowCapability

Not a fault in itself. Listed so you know the mod talks to something, and to what.

- **opencode CLI** — `curl -fsSL https://opencode.ai/install | bash`.
plugins/opencode-harness/skills/opencode-harness/SKILL.md · 52 lines

The source is not reproduced here

No licence file

A repository with no LICENSE is all rights reserved by default, so the body is not copied here. The metadata, the measurements and the link are.

Read it on GitHub

Files

What ships with it

3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 2mo ago First seen · 52 lines · 143 tokens per session scan C 355a9abe7cca

Subscribe to this mod's changes

opencode-harness is a skill published in the GitHub repository Human-Frontier-Labs-Inc/human-frontier-labs-marketplace (6 stars, last pushed 8d ago), with no licence file. It adds 143 tokens to every session and 970 once invoked, about $0.0006 per session on Opus 5.5. A static security scan graded it C with 2 findings (downloads and executes remote code, makes network calls). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-31.

Related

opencode-harness compared with skills from other repositories

opencode-harness next to 6 skills from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
opencode-harnessHuman-Frontier-Labs-Inc/human-frontier-labs-marketplaceSkill68d agononeC143Claude Code
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local-ai-agentsmicrosoft/ai-agents-for-beginnersSkill79k4d agoMITA200Claude Code, Codex
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next-cache-components-adoptionvercel/next.jsSkill143ktodayMITA95Claude Code