agentmods.dev

harness: Instructions file for Claude Code

CLAUDE.md

harness CLAUDE.md is an instructions file for Claude Code from mastersof-ai/harness. It costs 798 tokens per session, scanned A, original, MIT.

Project guidance for a standalone runtime that runs AI agents through a terminal interface or a web interface. It provides shared agent loading, tools, sub-agents, sessions, memory, and several access interfaces.

In plain words
What is it for?
Orienting yourself in the codebase, running the terminal or web application, working with agents and tools, and finding the relevant TypeScript, React, Fastify, and configuration files.
Why use it?
It helps contributors understand where the runtime, tools, web application, terminal interface, configuration, and authentication code belong. This reduces guesswork when changing the project.

Instructions file for Claude Code

Written for Claude Code: the file is CLAUDE.md. Also seen: mentions subagents.

This is mastersof-ai/harness's own configuration. It tells Claude Code how to work on harness 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 harness configures →

not rated 44repo +1 7mo ago A scan 798 tokens original MIT
View source ↗ mastersof-ai/harness
Reuse

Borrowing it

Nothing to install: this file belongs to mastersof-ai/harness. 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/mastersof-ai/harness/master/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/mastersof-ai/harness

Made for: Claude Code.

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 harness CLAUDE.md

README.md
[![agentmods](https://agentmods.dev/badge/instructions/mastersof-ai/harness/claude-md/github.svg)](https://agentmods.dev/instructions/mastersof-ai/harness/claude-md)
Your own site
<a href="https://agentmods.dev/instructions/mastersof-ai/harness/claude-md"><img src="https://agentmods.dev/badge/instructions/mastersof-ai/harness/claude-md/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 harness CLAUDE.md

Your own site · 80×15
<a href="https://agentmods.dev/instructions/mastersof-ai/harness/claude-md"><img src="https://agentmods.dev/badge/instructions/mastersof-ai/harness/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 798 This file is loaded in full into every session.
When invoked 798 The same file — it is already loaded in full.
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 $0.00798 $0.00798
Opus 5.5 $0.00319 $0.00319
Sonnet 5.5 $0.00160 $0.00160
Haiku 4.5 $0.00080 $0.00080

Measured 2mo ago against content hash 40995781a7c1, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

harness CLAUDE.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 2mo 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.

CLAUDE.md · 57 lines

How it starts

The opening of the file, as written. The whole thing — 57 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Masters Of AI Harness

  • DESIGN.md — overview with links to docs/
  • docs/ — architecture, agents, tools, configuration, sandbox, design decisions
  • CHANGELOG.md — version history

Quick Orientation

Standalone agent runtime built on top of the Claude Agent SDK. Two interfaces, one runtime:

  • Terminal TUI — mastersof-ai [--agent x] — React/Ink, single user, local
  • Web UI — mastersof-ai --serve — Fastify backend + React SPA frontend, multi-user, token auth

Both share agent loading, tools, sub-agents, sessions, and memory.

  • TypeScript, runs via tsx (no build step for backend)
  • Entry: bin/mastersof-ai.js → src/index.tsx
  • Agent loading: src/agent-context.ts + src/manifest.ts (frontmatter) → src/agent.ts
  • Tools: src/tools/ — in-process MCP servers, one per domain
  • Serve mode: src/serve.ts — Fastify HTTP/WS server (REST API + WebSocket streaming)
  • Web frontend: web/ — React + Vite + Tailwind SPA (deploys to Cloudflare Pages)
  • A2A: src/a2a/ — agent card generation, A2A protocol server/client
  • TUI: src/components/ — React/Ink (DO NOT TOUCH unless broken)
  • Config: ~/.mastersof-ai/config.yaml
  • Auth (serve mode): ~/.mastersof-ai/access.yaml
  • Security: src/env-safety.ts, src/url-safety.ts, src/content-safety.ts
  • Credentials: src/credentials.ts + src/egress-proxy.ts
  • Process isolation: src/ipc-protocol.ts, src/session-worker.ts, src/worker-manager.ts
  • WS protocol: src/ws-protocol.ts, src/sdk-stream.ts, src/query-mutex.ts
  • Health/observability: src/health.ts, src/rate-limit.ts, src/cost.ts
  • Privacy: src/privacy.ts — LGPD compliance
  • CLI subcommands: src/cli/ — modular command handlers

Running Locally

npx tsx bin/mastersof-ai.js                         # TUI with default agent
npx tsx bin/mastersof-ai.js --agent researcher      # TUI with specific agent
npx tsx bin/mastersof-ai.js --serve                 # Web UI server on port 3200
npx tsx bin/mastersof-ai.js --serve --port 5000     # Web UI on custom port
npx tsx bin/mastersof-ai.js --agent researcher --sandbox  # Bubblewrap sandbox
npx tsx bin/mastersof-ai.js --card                  # Output Agent Card JSON
npx tsx bin/mastersof-ai.js --list-agents

# CLI subcommands
npx tsx bin/mastersof-ai.js run billing "Run monthly billing"           # Headless run
npx tsx bin/mastersof-ai.js credentials check --agent billing           # Check agent credentials
npx tsx bin/mastersof-ai.js credentials migrate billing                 # Generate migration YAML
npx tsx bin/mastersof-ai.js access create --name partner --agents a,b   # Create access token
npx tsx bin/mastersof-ai.js access rotate --name partner                # Rotate token
npx tsx bin/mastersof-ai.js status billing                              # Recent run results
npx tsx bin/mastersof-ai.js preflight --agent billing                   # Validate full config
npx tsx bin/mastersof-ai.js create my-agent                             # Scaffold new agent

Read the full file on GitHub · 57 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. 2mo ago First seen · 57 lines · 798 tokens per session scan A 40995781a7c1

Subscribe to this mod's changes

harness CLAUDE.md is an instructions file published in the GitHub repository mastersof-ai/harness (44 stars, last pushed 7mo ago), licensed MIT. It adds 798 tokens to every session, about $0.0032 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 2026-08-30.

LLMa2a-protocolagent-runtimeagent-sdkai-agentclaude
Related

harness CLAUDE.md compared with instructions from other repositories

harness CLAUDE.md next to 6 instructions from other repositories
ModTypeStarsLast pushLicenceScanTokensWorks with
harness CLAUDE.mdmastersof-ai/harnessInstructions file447mo agoMITA798Claude Code
runtm copilot-instructions.mdruntm-ai/runtmInstructions file303yesterdaynoneA297GitHub Copilot
vscode buildNext.instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA9,719GitHub Copilot
next.js AGENTS.mdvercel/next.jsInstructions file143kyesterdayMITA7,461Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchainInstructions file149kyesterdayMITA4,680Codex, OpenCode
vscode oss-third-party-notices.instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA5,516GitHub Copilot
vscode copilot-instructions.mdmicrosoft/vscodeInstructions file195kyesterdayMITA3,093GitHub Copilot