# Ohloh / Black Duck Open Hub

> Ohloh is the open source directory and analytics service now known as Black Duck
> Open Hub (openhub.net). It tracks hundreds of thousands of open source projects,
> their code, contributors, languages, licenses and activity, and exposes the data
> through a public REST API that returns XML.

Generated: 2026-07-20
Method: generated (from the API Evangelist catalog + provider documentation)
Source: https://github.com/blackducksoftware/ohloh_api

## API

- Base URL: https://www.openhub.net
- Style: REST over HTTPS; resource URLs take a `.xml` suffix (e.g. `/p/1.xml`). XML only, no JSON.
- Response envelope: XML wrapped in `<response>`, which always contains `<status>` (success|failed); an `<error>` element with help text is present on failure.
- Authentication: `api_key` HTTP query parameter for read access; OAuth 2.0 for write access and private account data. Register a key at https://www.openhub.net/accounts/me/api_keys/new (up to 5 apps per account).
- Rate limit: 1,000 requests per API key per day (contact info@openhub.net for more).
- Pagination: `page` (one-based), `query`, `sort` parameters; at most 25 items per page; responses report `items_returned`, `items_available`, `first_item_position`.

## Resources

- Project — /p/{id}.xml (name, description, homepage_url, analysis, languages, licenses, tags, factoids)
- Account — contributor accounts
- Organization — organizations and their affiliated/portfolio projects
- Analysis — the current best analysis of a project
- Activity Fact / Size Fact — monthly activity and codebase size history
- Contributor Fact / Contributor Language Fact — who contributed and in which languages
- Language — programming language directory and stats
- Stack / Stack Entry — software stacks for accounts and projects
- Factoid — codebase and team insights
- Kudo / Kudo Score — peer recognition
- Position — contributor positions on projects
- Enlistment / Code Location — repositories analyzed for a project
- Email Lookup — resolve an account by email hash

## Documentation

- API docs and reference: https://github.com/blackducksoftware/ohloh_api
- Resource reference: https://github.com/blackducksoftware/ohloh_api/tree/master/reference
- Getting started (README): https://github.com/blackducksoftware/ohloh_api/blob/master/README.md
- API Use Agreement (terms): https://community.blackduck.com/s/article/Black-Duck-Open-Hub-API-Use-Agreement
- Website: https://www.openhub.net
- GitHub organization: https://github.com/blackducksoftware

## Notes

- Ohloh was rebranded Black Duck Open Hub; the API repository is still named `ohloh_api`.
- Attribution linking back to openhub.net is required by the API Use Agreement.