harness-evals: Instructions file for Codex

AGENTS.md

harness-evals AGENTS.md is an instructions file for Codex, OpenCode from harness/harness-evals. It costs 8,079 tokens per session, scanned A, original, Apache-2.0.

Project instructions for harness-evals, an open-source Python framework that scores AI agents, prompts, and structured outputs.

In plain words
What is it for?
Use them when developing or evaluating harness-evals metrics, including deterministic, reliability, retrieval, safety, agent, conversation, MCP, or security evaluations.
Why use it?
They explain the project’s package names, installation options, data flow, scoring model, and testing and formatting expectations.

Instructions file for CodexOpenCode

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

This is harness/harness-evals's own configuration. It tells Codex and OpenCode how to work on harness-evals 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-evals configures →

Reuse

Borrowing it

Nothing to install: this file belongs to harness/harness-evals. 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/harness/harness-evals/main/AGENTS.md
Clone the repo
git clone --depth 1 https://github.com/harness/harness-evals

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.

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README.md
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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.

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Per session 8,079 This file is loaded in full into every session.
When invoked 8,079 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 $0.08079 $0.08079
Opus 5.5 $0.03232 $0.03232
Sonnet 5.5 $0.01616 $0.01616
Haiku 4.5 $0.00808 $0.00808

Measured 8d ago against content hash 1215b5faee9c, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

harness-evals 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 8d 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 · 637 lines

How it starts

The opening of the file, as written. The whole thing — 637 lines — stays where its author put it; the contents beside it link to each section on GitHub.

AGENTS.md - harness-evals

Project Overview

harness-evals is an open-source AI evaluation framework for LLM agents, prompts, and structured outputs. It provides a pip install-able scoring engine with 70+ metrics across deterministic, structural, operational, reliability, predictability, MCP, similarity, LLM-judged, RAG, grounding, safety, agent, conversation, and security categories.

Core principle: Every applicable metric produces a Score. A metric may return None to skip a case; skipped results are excluded from aggregation, not converted to failed or zero scores. Every metric is a single class with a measure() method.

Data flow: Golden (authored) + agent output -> EvalCase (evaluated) -> Score (result)

Language: Python 3.10+ License: Apache 2.0 Package name: harness-evals Import name: harness_evals

Build System

pip install -e "."                # Core only (deterministic metrics, no LLM key needed)
pip install -e ".[llm]"           # + OpenAI, Anthropic for LLM-judged metrics
pip install -e ".[otlp]"          # + OTLP metrics & traces export
pip install -e ".[langfuse]"      # + Langfuse source/sink
pip install -e ".[harness]"       # + Harness AI Service LLM provider
pip install -e ".[benchmarks]"    # + Academic benchmarks (MMLU, GSM8K, HumanEval, etc.)
pip install -e ".[all]"           # Everything
poetry install --all-extras --with dev  # Everything + the Poetry dev group

Build tool: Poetry via pyproject.toml (backend: poetry-core) No compiled extensions — pure Python.

Testing

pytest tests/ -v                              # All tests
pytest tests/ -v -m unit                      # Unit tests only
pytest tests/metrics/ -v                      # Specific directory
pytest tests/test_core.py -v                  # Specific file
pytest tests/test_core.py::test_evaluate -v   # Specific function
pytest tests/ --cov=harness_evals --cov-report=html  # With coverage
  • Mark tests: @pytest.mark.unit, @pytest.mark.integration
  • Test data: tests/data/

Read the full file on GitHub · 637 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. 8d ago Changed · +73 lines · +985 tokens per session 1215b5faee9c
  2. 9d ago Changed · +80 lines · +1,056 tokens per session 518c3906ef07
  3. 1mo ago Changed 777872f3e1d3
  4. 1mo ago Changed · +6 lines · +105 tokens per session 2ea1cfff9a74
  5. 2mo ago Changed · +11 tokens per session 91b89a5f1d6e
  6. 2mo ago First seen · 478 lines · 5,922 tokens per session scan A 1fd9c3a133a7

Subscribe to this mod's changes

harness-evals AGENTS.md is an instructions file published in the GitHub repository harness/harness-evals (38 stars, last pushed 3d ago), licensed Apache-2.0. It adds 8,079 tokens to every session, about $0.0323 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.

Related

harness-evals AGENTS.md compared with instructions from other repositories

harness-evals AGENTS.md next to 6 instructions from other repositories
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harness-evals AGENTS.mdharness/harness-evalsInstructions file383d agoApache-2.0A8,079Codex, OpenCode
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vscode copilot-instructions.mdmicrosoft/vscodeInstructions file195ktodayMITA3,093GitHub Copilot
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