What is chp-core AGENTS.md?

A project instruction file for the Capability Host Protocol, a Python protocol and software kit for making agent and tool runs observable, replayable, and governed by policies. It defines three rules that changes must not break, plus commands and test guidance.

Use it as the repository's operating guidance when changing the protocol or Python SDK. It covers append-only evidence storage, correlation IDs, alignment checks, and fast and full test suites.

It helps coding agents work on this repository without corrupting its evidence history, losing request-tracking IDs, or letting specifications and code drift apart.

How capabilityhostprotocol/chp-core configures Codex and OpenCode

Reuse

Borrowing it

Nothing to install: this file belongs to capabilityhostprotocol/chp-core. 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/capabilityhostprotocol/chp-core/main/AGENTS.md

Clone the repo

git clone --depth 1 https://github.com/capabilityhostprotocol/chp-core

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.

README.md

[![agentmods](https://agentmods.dev/badge/instructions/capabilityhostprotocol/chp-core/agents-md/github.svg)](https://agentmods.dev/instructions/capabilityhostprotocol/chp-core/agents-md)

Your own site

<a href="https://agentmods.dev/instructions/capabilityhostprotocol/chp-core/agents-md"><img src="https://agentmods.dev/badge/instructions/capabilityhostprotocol/chp-core/agents-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.

Your own site · 80×15

<a href="https://agentmods.dev/instructions/capabilityhostprotocol/chp-core/agents-md"><img src="https://agentmods.dev/badge/instructions/capabilityhostprotocol/chp-core/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 775 This file is loaded in full into every session.

When invoked 775 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.

Model	Per session	Once invoked
Fable 5.1	$0.00775	$0.00775
Opus 5.5	$0.00310	$0.00310
Sonnet 5.5	$0.00155	$0.00155
Haiku 4.5	$0.00077	$0.00077

Measured 2mo ago against content hash 09b7bb264227, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

chp-core 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 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.

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.

AGENTS.md — Capability Host Protocol

CHP is a protocol and Python SDK for making agent, tool, and system execution observable, replayable, and governable. Every function wrapped as a @capability gets automatic evidence emission, correlation propagation, replay by session ID, and optional policy enforcement — with zero mandatory infrastructure. The reference host is LocalCapabilityHost in packages/python/chp_core/.

Three invariants you must never violate

Evidence is append-only. Never modify or delete rows in an evidence SQLite store. The SHA256 hash chain breaks if any row changes. store.py is insert-only by design.
Preserve caller correlation IDs. If an InvocationEnvelope arrives with a correlation_id, the host must forward it verbatim into every evidence event and the result. Never generate a new ID over a supplied one.
Spec, schemas, and types must stay in sync. Any change to spec/chp-v0.1.md, schemas/*.json, or packages/python/chp_core/types.py must be validated with chp work check-alignment --repo-root . (runs 41 cross-artifact checks). CI will catch drift, but run it locally first.

Key commands

# Fast test suite (~6s)
cd packages/python && python -m pytest tests/ -m "not slow" -q --no-cov

# Full test suite
cd packages/python && python -m pytest tests/ -q --no-cov

# Protocol conformance (9 checks)
python conformance/runner.py

# Spec/schema/type alignment (41 checks)
PYTHONPATH=packages/python chp work check-alignment --repo-root .

# Wire evidence capture for every Claude Code session
PYTHONPATH=packages/python chp hooks install

Where to look	What you'll find
`spec/chp-v0.1.md`	Normative protocol — start here for definitions and MUST/SHOULD requirements
`schemas/`	JSON Schema for every protocol object (29 files)
`packages/python/chp_core/host.py`	`LocalCapabilityHost` — registration, invocation, evidence emission
`packages/python/chp_core/store.py`	`SQLiteEvidenceStore` — append-only, SHA256-chained
`packages/python/chp_core/types.py`	Python dataclasses for all protocol objects
`conformance/runner.py`	9 conformance checks against a live host
`docs/adopter-quickstart.md`	10-minute path to first evidence event
`examples/`	14 runnable demos

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.

2mo ago First seen · 49 lines · 775 tokens per session scan A 09b7bb264227

Subscribe to this mod's changes

chp-core AGENTS.md is an instructions file published in the GitHub repository capabilityhostprotocol/chp-core (1 stars, last pushed 27d ago), licensed Apache-2.0. It adds 775 tokens to every session, about $0.0031 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 2026-08-31.

Building agents LLM agents evidence governance observability protocol

chp-core AGENTS.md next to 6 instructions from other repositories
Mod	Type	Stars	Last push	Licence	Scan	Tokens	Works with
chp-core AGENTS.mdcapabilityhostprotocol/chp-core	Instructions file	1	27d ago	Apache-2.0	A	775	Codex, OpenCode
vscode buildNext.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	9,719	GitHub Copilot
vscode oss-third-party-notices.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	5,516	GitHub Copilot
next.js AGENTS.mdvercel/next.js	Instructions file	143k	yesterday	MIT	A	7,461	Codex, OpenCode
langchain AGENTS.mdlangchain-ai/langchain	Instructions file	149k	today	MIT	A	4,680	Codex, OpenCode
vscode copilot-instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	3,093	GitHub Copilot
vscode model-prompts.instructions.mdmicrosoft/vscode	Instructions file	195k	today	MIT	A	2,022	GitHub Copilot

chp-core: Instructions file for Codex