developer-api
(6)
HeyGen
HeyGen wants to make the camera optional. Its digital twins, translation tools and video agents turn one human performance into a production system that can speak to almost anyone.
VOYGR
VOYGR is a place-intelligence API that validates whether real-world businesses are actually operating and enriches their records with fresh web context - news, articles, hours, prices and events. Built by ex-Google Maps, Apple and Meta engineers, it is designed to give AI apps and agents map data they can trust, going beyond the 10-15 static attributes offered by traditional mapping APIs.
AssemblyAI
AssemblyAI is a San Francisco speech-AI company that builds and serves models turning audio and video into accurate text, plus higher-level 'audio intelligence' like summaries, sentiment, speaker labels, and PII redaction. Founded in 2017 by Dylan Fox, it sells a developer-first API used to add transcription, real-time streaming, and voice-agent capabilities to software. The company has raised more than $113M across seed to Series C and reports processing over a million hours of audio a day for customers ranging from startups to large enterprises.
Reducto
Reducto is a San Francisco AI company that turns messy, complex documents into clean, LLM-ready data. Its agentic document platform pairs traditional computer vision with vision-language models and a multi-pass 'Agentic OCR' correction loop to parse, split, extract, classify, and even edit PDFs and other formats through a developer API. Founded in 2023 by MIT grads Adit Abraham and Raunak Chowdhuri, Reducto has processed billions of pages for AI teams and enterprises in finance, healthcare, legal, insurance, and compliance, and raised $108M total including a $75M Series B led by Andreessen Horowitz in October 2025.
Tavus
Tavus is a San Francisco AI company building the interface for face-to-face conversation between humans and machines. Its Conversational Video Interface (CVI) lets developers add real-time, emotionally aware AI video agents - what Tavus calls PALs - to any app through an API. Backed by CRV, Sequoia, Scale Venture Partners, Y Combinator and HubSpot Ventures, Tavus raised a $40M Series B in November 2025, bringing total funding to roughly $82M.
Knot
Knot is a New York merchant connectivity platform that lets banks, fintechs, and card issuers move their customers' cards on file across hundreds of online merchants - automatically. Through APIs like CardSwitcher, TransactionLink, AccountUpdater, and SubscriptionManager, Knot helps issuers win the top-of-wallet spot, cut payment declines, and surface SKU-level spending data, all without users manually re-entering their card details at Netflix, Amazon, PayPal, and more.