mcp-folk: Instructions file for Claude Code

CLAUDE.md

mcp-folk CLAUDE.md is an instructions file for Claude Code from NimbleBrainInc/mcp-folk. It costs 1,111 tokens per session, scanned A, original, MIT.

Project instructions for mcp-folk, a server that lets an agent work with Folk CRM through its web API. A CRM is software for storing and managing contacts, companies, and customer relationships.

In plain words
What is it for?
Use it when developing, deploying, or configuring mcp-folk, or when adding and troubleshooting tools for finding people and companies in Folk CRM.
Why use it?
It documents the server structure, startup methods, secure API-key setup, and available CRM operations, reducing configuration errors.

Instructions file for Claude Code

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

This is NimbleBrainInc/mcp-folk's own configuration. It tells Claude Code how to work on mcp-folk 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 mcp-folk configures →

Reuse

Borrowing it

Nothing to install: this file belongs to NimbleBrainInc/mcp-folk. 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/NimbleBrainInc/mcp-folk/main/CLAUDE.md
Clone the repo
git clone --depth 1 https://github.com/NimbleBrainInc/mcp-folk

Made for: Claude Code.

Wrote this? Show the measurements

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README.md
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<a href="https://agentmods.dev/instructions/nimblebraininc/mcp-folk/claude-md"><img src="https://agentmods.dev/badge/instructions/nimblebraininc/mcp-folk/claude-md.svg" alt="Measured on agentmods" height="20"></a>
Per session 1,111 This file is loaded in full into every session.
When invoked 1,111 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 5.1 $0.01111 $0.01111
Opus 5 $0.00556 $0.00556
Sonnet 5 $0.00222 $0.00222
Haiku 4.5 $0.00111 $0.00111

Measured 6d ago against content hash 8d6fd9a5ebe3, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-06, from the pricing page.

Security

Grade A, and why

mcp-folk 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 6d 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 · 158 lines

How it starts

The opening of the file, as written. The whole thing — 158 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Folk CRM MCP Server

MCP server providing Folk CRM functionality via Folk's REST API.

Architecture

src/mcp_folk/
├── server.py      # MCP tools (FastMCP) + stdio entrypoint
├── api_client.py  # Async HTTP client for Folk API
└── api_models.py  # Pydantic models for API responses

Critical

  • Package name: @nimblebraininc/folk (npm-style, matches GitHub org)
  • Manifest uses module execution: python -m mcp_folk.server
  • Server needs both entrypoints:
    app = mcp.http_app()  # HTTP deployment
    if __name__ == "__main__":
        mcp.run()  # Stdio for Claude Desktop / mpak
    

user_config

API key configured via manifest user_config, not hardcoded:

{
  "user_config": {
    "api_key": {
      "type": "string",
      "sensitive": true,
      "required": true
    }
  },
  "server": {
    "mcp_config": {
      "env": { "FOLK_API_KEY": "${user_config.api_key}" }
    }
  }
}

Available Tools

AI-friendly tools designed for minimal token usage and intent-based operations.

Search (Tier 1 - Use First)

Tool Purpose Returns
find_person(name) Find people by name {found, matches: [{id, name, email}], total}
find_company(name) Find companies by name {found, matches: [{id, name, industry}], total}

Details (Tier 2 - After Finding)

Tool Purpose
get_person_details(person_id) Full person info after finding
get_company_details(company_id) Full company info after finding

Browse (Tier 3 - Exploration)

Tool Purpose
browse_people(page, per_page) Paginated list of all people
browse_companies(page, per_page) Paginated list of all companies

Actions (Tier 4 - Mutations)

Tool Purpose
add_person(first_name, ...) Create new person
add_company(name, ...) Create new company
update_person(person_id, ...) Update person fields
update_company(company_id, ...) Update company fields
delete_person(person_id) Delete a person
delete_company(company_id) Delete a company

Read the full file on GitHub · 158 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. 6d ago First seen · 158 lines · 1,111 tokens per session scan A 8d6fd9a5ebe3

Subscribe to this mod's changes

mcp-folk CLAUDE.md is an instructions file published in the GitHub repository NimbleBrainInc/mcp-folk (6 stars, last pushed 3mo ago), licensed MIT. It adds 1,111 tokens to every session, about $0.0056 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 2026-08-31.

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