mcp-server-datahub: Instructions file for Claude Code

CLAUDE.md

mcp-server-datahub CLAUDE.md is an instructions file for Claude Code from acryldata/mcp-server-datahub. It costs 592 tokens per session, scanned A, original, Apache-2.0.

Project instructions for a DataHub MCP server, a service that lets coding agents search metadata, follow data lineage, and list SQL queries. They cover setup, commands, testing, architecture, and authentication.

In plain words
What is it for?
Use them when developing, testing, linting, or running the DataHub server and its FastMCP development environment.
Why use it?
They tell an agent how this repository works and how to run its checks without guessing about its tools or live DataHub requirements.

Instructions file for Claude Code

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

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

Reuse

Borrowing it

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

Made for: Claude Code.

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Per session 592 This file is loaded in full into every session.
When invoked 592 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 $0.00592 $0.00592
Opus 5 $0.00296 $0.00296
Sonnet 5 $0.00118 $0.00118
Haiku 4.5 $0.00059 $0.00059

Measured 8d ago against content hash 178bd41eaa54, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-08, from the pricing page.

Security

Grade A, and why

mcp-server-datahub 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 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.

Origin

Copies of this mod

1 near-identical copy found in the catalogue:

CLAUDE.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

CLAUDE.md

This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.

Project Overview

This is a Model Context Protocol (MCP) server implementation for DataHub. The server provides tools for searching entities, fetching metadata, traversing lineage graphs, and listing SQL queries. It's built using the FastMCP framework and integrates with DataHub's GraphQL API.

Development Commands

See DEVELOPING.md and Makefile for more details.

A quick summary is below:

  • make setup - Set up development environment (requires uv)
  • make lint - Run ruff formatting, linting and type checking
  • make test - Run pytest tests (requires live DataHub instance)
  • make clean - Clean up build artifacts

Testing

  • Run all tests: make test
  • Single test file: uv run pytest tests/test_mcp_server.py
  • Tests require a live DataHub instance with proper authentication

Development Setup

Run the server using MCP inspector for development:

uv run fastmcp dev src/mcp_server_datahub/__main__.py --with-editable .

Note: Use fastmcp dev (not mcp dev), since this project uses the standalone FastMCP package.

Architecture

Core Components

  • mcp_server.py: Main server implementation with MCP tools

    • get_entity(): Fetch entity metadata by URN
    • search(): Search across DataHub entities with filters
    • get_dataset_queries(): Get SQL queries for datasets
    • get_lineage(): Traverse upstream/downstream lineage
  • GraphQL Integration: Uses GraphQL fragments for efficient queries

    • gql/search.gql: Search queries
    • gql/entity_details.gql: Entity metadata queries
    • gql/queries.gql: SQL query retrieval
  • Client Management: Context-aware DataHub client handling

    • Uses contextvars for thread-safe client management
    • Supports both DataHub Cloud and on-premise instances

Key Patterns

  • All tools return cleaned GraphQL responses (removes __typename fields)
  • DataHub Cloud instances get URL injection for entities
  • Filter compilation uses DataHub SDK's compile_filters()
  • Lineage traversal supports configurable hop limits (1-3+ degrees)

Read the full file on GitHub · 74 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 First seen · 74 lines · 592 tokens per session scan A 178bd41eaa54

Subscribe to this mod's changes

mcp-server-datahub CLAUDE.md is an instructions file published in the GitHub repository acryldata/mcp-server-datahub (80 stars, last pushed 3d ago), licensed Apache-2.0. It adds 592 tokens to every session, about $0.0030 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.

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