OpenVisionAPI
Open source computer vision API based on open source models
NLP API to return probability that if text is toxic, obscene, insulting or threatening.
Perspective API is a free Machine Learning API that requires apiKey authentication, is served over HTTPS and has unconfirmed CORS support.
Perspective API is a free developer tool that helps platforms host conversations that flourish - on their own terms.
Details from perspectiveapi.com.

Unified API suite · now live
Geocode an address, validate an email, track a flight or pull stock data with one account, one dashboard and one API key.
Open source computer vision API based on open source models
Unified API for 300+ LLMs from OpenAI, Anthropic, Meta, Mistral and more, with a free tier
OpenAI-compatible, about 30 free LLMs, 30 calls per 5 hours, optional pay-as-you-go, public beta
The Perspective API is provided by Perspective API (perspectiveapi.com). Perspective API is a free developer tool that helps platforms host conversations that flourish - on their own terms.
Yes. The Perspective API is listed in the Machine Learning category of the public-apis directory, which only includes APIs that are free or have a free tier. Check its documentation for rate limits and paid plans.
Yes. The Perspective API uses apiKey authentication, so you need to register for credentials before making requests.
CORS support for the Perspective API is unknown. Test a request from the browser, and fall back to a server-side call if it is blocked.
Yes. The Perspective API is served over HTTPS, so it's safe to use in production.