OpenMetadata is an open platform that organizes information about data, including its meaning, ownership, quality, history, and relationships. It provides governed context for data users, AI assistants, and agents that need to discover and understand trustworthy data.
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.
npx skills add open-metadata/OpenMetadata --skill tddgit clone --depth 1 https://github.com/open-metadata/OpenMetadataWrote 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/skills/open-metadata/openmetadata/tdd)<a href="https://agentmods.dev/skills/open-metadata/openmetadata/tdd"><img src="https://agentmods.dev/badge/skills/open-metadata/openmetadata/tdd/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/skills/open-metadata/openmetadata/tdd"><img src="https://agentmods.dev/badge/skills/open-metadata/openmetadata/tdd.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00050 | $0.01171 |
| Opus 5.5 | $0.00020 | $0.00468 |
| Sonnet 5.5 | $0.00010 | $0.00234 |
| Haiku 4.5 | $0.00005 | $0.00117 |
Grade A, and why
tdd 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 — 137 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Test-Driven Development for OpenMetadata
Enforce RED-GREEN-REFACTOR discipline across all three language stacks.
When to Use
- Implementing any new feature or behavior
- Fixing bugs (write a test that reproduces the bug first)
- Adding new API endpoints, connectors, or UI components
The Cycle
1. RED - Write a Failing Test
Write the smallest test that describes the desired behavior. Run it. It must fail. If it passes, your test isn't testing the new behavior.
Java (JUnit 5):
# Write test in openmetadata-service/src/test/ or openmetadata-integration-tests/
mvn test -pl openmetadata-service -Dtest=YourTestClass#yourTestMethod
Python (pytest):
source env/bin/activate
cd ingestion
# Write test using pytest style — plain assert, no unittest.TestCase
python -m pytest tests/unit/your_test.py::test_your_function -v
TypeScript (Jest):
cd openmetadata-ui/src/main/resources/ui
yarn test path/to/YourComponent.test.ts
Rules for RED:
- Test one behavior per test
- Use descriptive test names that explain what should happen
- Assert on observable outcomes (API responses, database state, rendered output), not internal method calls
- For Python: use
assert x == y, notself.assertEqual(x, y)
2. GREEN - Write the Minimum Code to Pass
Write only the code needed to make the test pass. No more.
- Don't add error handling for cases you haven't tested
- Don't generalize — hardcode if that's what the test requires
- Don't clean up or refactor yet
Run the test again. It must pass.
3. REFACTOR - Clean Up While Green
Now improve the code while keeping tests green:
- Remove duplication
- Improve naming
- Extract methods if needed (but don't over-abstract)
- Run the full test suite for the module to check for regressions
# Java — format then test
mvn spotless:apply
mvn test -pl openmetadata-service
# Python — format, lint, then test
cd ingestion && make py_format && make py_format_check
python -m pytest tests/unit/your_test.py -v
# TypeScript — lint then test
cd openmetadata-ui/src/main/resources/ui
yarn lint:fix
yarn test path/to/YourComponent.test.ts
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 First seen · 137 lines · 50 tokens per session scan A bd995ea9698e
tdd is a skill published in the GitHub repository open-metadata/OpenMetadata (15,506 stars, last pushed today), licensed Apache-2.0. It adds 50 tokens to every session and 1,171 once invoked, about $0.0002 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 skills, from other repositories
test-review
You are an expert DataHub test reviewer. Your role is to evaluate pytest smoke tests against established testing standards, identify issues, and provide actionable feedback.
tika-eval-compare
Compare extracts from two Tika builds over a corpus to detect regressions in content, encoding, exceptions, and embedded-document handling. Use for "compare before/after extracts", "eval this change against the corpus".
engram-testing-coverage
TDD and coverage standards for Engram. Trigger: When implementing behavior changes in any package.
conductor-implement
Execute tasks from a track's implementation plan following TDD workflow.
principle-test-behavior-not-implementation
Apply when you write, change, or keep a test. Assert what the code's users can observe, so that the test fails when that behavior breaks and keeps passing when only the internals change.
iterative-development
TDD iteration loops using Claude Code Stop hooks - runs tests after each response, feeds failures back automatically.