DataHub is an open-source metadata platform that catalogs data assets so people can find, understand, govern, and monitor data across an organization’s data ecosystem. Data teams use it for data discovery, governance, observability, and answering questions about cataloged data with an analytics agent.
Borrowing it
Nothing to install: this file belongs to datahub-project/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.
curl -O https://raw.githubusercontent.com/datahub-project/datahub/master/AGENTS.mdgit clone --depth 1 https://github.com/datahub-project/datahubWrote 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.
[](https://agentmods.dev/instructions/datahub-project/datahub/agents-md)<a href="https://agentmods.dev/instructions/datahub-project/datahub/agents-md"><img src="https://agentmods.dev/badge/instructions/datahub-project/datahub/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.
<a href="https://agentmods.dev/instructions/datahub-project/datahub/agents-md"><img src="https://agentmods.dev/badge/instructions/datahub-project/datahub/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.07363 | $0.07363 |
| Opus 5.5 | $0.02945 | $0.02945 |
| Sonnet 5.5 | $0.01473 | $0.01473 |
| Haiku 4.5 | $0.00736 | $0.00736 |
Grade A, and why
datahub 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 1mo 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.
How it starts
The opening of the file, as written. The whole thing — 724 lines — stays where its author put it; the contents beside it link to each section on GitHub.
DataHub — Agent Development Guide
This is the canonical reference for working with the DataHub codebase. It applies to all coding agents (Claude Code, Cursor, Codex CLI, Devin, etc.) and human developers alike.
Code Navigation (LSP)
Prefer LSP tools over Grep for code navigation tasks:
- Use
goToDefinitionto find where something is defined - Use
findReferencesto find all call sites - Use
workspaceSymbolto find symbols by name - Use diagnostics after any edit to catch type errors immediately
See docs/lsp-setup.md for installation and configuration.
Essential Commands
Build and test:
./gradlew build # Build entire project
./gradlew check # Run all tests (Python/JS lint lives in lint-jobs.yml / :module:lint)
./gradlew lintCheck # Run all lint checks (Python, JS, GraphQL, markdown, Java)
./gradlew lintFix # Auto-fix all lint issues
./gradlew format # Format all code (Java, Markdown, GraphQL, YAML)
# Note that each directory typically has a build.gradle file, but the available tasks follow similar conventions.
# Java code.
./gradlew spotlessApply # Java code formatting
# Python code.
./gradlew :metadata-ingestion:testQuick # Fast Python unit tests
./gradlew :metadata-ingestion:lint # Python linting (ruff, mypy)
./gradlew :metadata-ingestion:lintFix # Python linting auto-fix (ruff only)
# Markdown, GraphQL, YAML formatting
./gradlew :datahub-web-react:mdPrettierWrite # Format markdown files
./gradlew :datahub-web-react:graphqlPrettierWrite # Format GraphQL schemas
./gradlew :datahub-web-react:githubActionsPrettierWrite # Format GitHub Actions
IMPORTANT: Verifying Python code changes:
- ALWAYS use
./gradlew :metadata-ingestion:lintFixto verify Python code changes - NEVER use
python3 -m py_compile- it doesn't catch style issues or type errors - NEVER use
rufformypycommands directly - use the Gradle task instead - lintFix runs ruff formatting and fixing automatically, ensuring code quality
- For smoke-test changes, the lintFix command will also check those files
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.
- 1mo ago Changed · +4 lines · +118 tokens per session ad79f68b82e3
- 1mo ago First seen · 720 lines · 7,245 tokens per session scan A 878037f1fa6d
datahub AGENTS.md is an instructions file published in the GitHub repository datahub-project/datahub (12,873 stars, last pushed today), licensed Apache-2.0. It adds 7,363 tokens to every session, about $0.0295 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.
Other instructions, from other repositories
vscode buildNext.instructions.md
Working notes and architecture documentation for the new esbuild-based build system in build/next. Use when making changes to the new build pipeline (transpile/bundle commands, NLS plugin, source-map handling, resource copying, or self-hosting watch tasks).
next.js AGENTS.md
AGENTS.md instructions for vercel/next.js, covering next.js development guide, codebase structure, monorepo overview, core package: packages/next and other important packages.
vscode oss-third-party-notices.instructions.md
Instructions for microsoft/vscode, covering vs code oss third-party-notices pipeline, architecture, pipeline flow in ci, cache eligibility and rollout and applying the notice (cutover).
langchain AGENTS.md
AGENTS.md instructions for langchain-ai/langchain, covering global development guidelines for the langchain monorepo, corridor security analysis, project architecture and context, monorepo structure and development tools & commands.
vscode copilot-instructions.md
Copilot instructions for microsoft/vscode, covering vs code copilot instructions, project overview, root folders, core architecture (src/ folder) and built-in extensions (extensions/ folder).
deno copilot-instructions.md
Copilot instructions for denoland/deno, covering deno development guide for github copilot, network access, high level overview, key directories and key files to understand first.