Freelancer vs Redash

Freelancer's API mirrors the full marketplace — projects, bids, milestones, messages, and user profiles — behind a standard OAuth 2.0 app-registration flow: a live call to `/api/users/0.1/self/` returns 401 `NOT_AUTHENTICATED` rather than any keyless access, and the OPTIONS preflight explicitly whitelists a custom `Freelancer-OAuth-V1` header, reconfirming OAuth as the real mechanism. A GET against the public `/api/projects/0.1/projects/active/` endpoint succeeds with no key at all and echoes `access-control-allow-origin: *` on both the GET and its preflight, resolving the stored 'unknown' CORS value to fully open. Freelancer's own Python SDK and developer portal document no separate paid tier or metering for the API itself — registering an app is free, with the marketplace's usual project fees applying only to actual freelance transactions, not API calls.

Redash is an open-source query and dashboard tool that lets teams connect to a data source, write a query, and visualize the results without writing frontend code. Its REST API, documented live at redash.io/help/user-guide/integrations-and-api/api, authenticates each request with a per-user API key sent as `Authorization: Key <api_key>` and lets scripts create queries, trigger refreshes, and pull dashboard results as JSON. Redash Inc.'s hosted SaaS at app.redash.io was discontinued in 2021, so the project now ships only as free, self-hosted open-source software with no vendor-run instance to point the API at.