chimp AGENTS.md

A set of development instructions for Chimp, a Scala 3 toolkit for building MCP servers and clients. It covers protocol rules, test organization, conformance testing, and documentation.

In plain words
What is it for?
Use it when changing Chimp’s protocol support, shared tests, conformance tests, or documentation.
Why use it?
It keeps changes aligned with the MCP specification and the project’s testing and documentation practices. This reduces the risk of incompatible behavior or misplaced tests.

Instructions file for CodexOpenCode

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.

agentmods
npx agentmods add instructions/softwaremill/chimp/agents-md
Clone the repo
git clone --depth 1 https://github.com/softwaremill/chimp

Made for: Codex, OpenCode.

Per session 342 This file is loaded in full into every session.
When invoked 342 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
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 $0.00342 $0.00342
Opus 5 $0.00171 $0.00171
Sonnet 5 $0.00068 $0.00068
Haiku 4.5 $0.00034 $0.00034

Measured 2d ago against content hash 1de1d60d9ac9, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

chimp 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 2d 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 · 46 lines

What it actually says

Overview

Chimp is an SDK for building MCP (Model Context Protocol) servers and clients in Scala 3 using boilerplate-less, type-safe APIs based on Tapir and sttp, supporting the variety of the Scala ecosystem.

This is public OSS project.

Rules

1 - Protocol Conformance

Supported protocol version are located in chimp.protocol.ProtocolVersion. ALWAYS refer and check your implementation against the official MCP specification https://modelcontextprotocol.io/specification.

2 - Tests organization

Most MCP behaviour is identical across transports and effect backends, such tests are defined once and run everywhere. When implementing tests ALWAYS place them in shared trait's unless they are somehow specific.

3 - Conformance tests

When working with conformance tests ALWAYS refer to the actual sources https://github.com/modelcontextprotocol/conformance.

For instructions on client conformance refer to /client-conformance/README.md. For instructions on server conformance refer to /server-conformance/README.md.

4 - Documentation

Document a change ONLY when it is:

  • non-obvious to the users
  • specific to a particular effect backend
  • implementing support for a new protocol feature

For specific instructions on working with the docs refer to /docs/README.md.

5 - Language

ALWAYS use ASD-STE100 Simplified Technical English for documentation, responses and user interactions.

6 - Code comments

NEVER add any comments in the code, unless you're asked to do so.

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. 2d ago First seen · 46 lines · 342 tokens per session scan A 1de1d60d9ac9

Subscribe to this mod's changes

chimp AGENTS.md is an instructions file published in the GitHub repository softwaremill/chimp (102 stars, last pushed 7d ago), licensed Apache-2.0. It adds 342 tokens to every session, about $0.0017 per session on Opus 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.