← Startups in San Francisco

San Francisco API 63 startups

"API" Startups in San Francisco

Every active San Francisco startup we index that carries the "API" tag.

All startups in San Francisco → "API" startups nationwide →

Last updated

2026-09-02

Hiring right now 11% 7 of 63

Open roles 261

City San Francisco

Our index currently lists 63 tech startups in San Francisco tagged "API" — a city×tag slice of the live directory, not every "API" company nationwide and not every San Francisco startup regardless of tag. 11% of this slice is hiring right now (7 of 63). Apply links on each profile go to the company's own site; we don't act as a middleman. "API" startups in San Francisco include Alpaca, Checkr, Deepgram, Gigs, and Nango. Categories represented here: AI / ML, Dev Tools, and Infrastructure. YC batches in this slice: Sp26, W23, W25, and W19, among others. Widen the view anytime: all San Francisco startups at /startups/location/san-francisco, or every "API" company nationwide at /startups/tag/api.

API-first stock and crypto brokerage platform

Developer ToolsFintechAPI

People infrastructure for the future of work

Artificial IntelligenceComplianceHR Tech

Building foundational AI for speech transcription and understanding.

AI-Enhanced LearningAPIAI

The OS for Embedded Telecom

FintechHR TechAPI

A single API for all your integrations

Developer ToolsSaaSOpen Source

Agent simulation and RL for researchers

AIOpsArtificial IntelligenceAPI

Email Inboxes for AI Agents

Developer ToolsAPIEmail

Phone Numbers for AI Agents

Artificial IntelligenceDeveloper ToolsAPI

API sandboxes, built for AI agents

Artificial IntelligenceDeveloper ToolsAPI

Stablecoin API for global payments

Developer ToolsFintechCrypto / Web3

Leading open-source web agent project with 50k stars in 3 months

Artificial IntelligenceOpen SourceAPI

Accurate, high-performance retrieval for AI agents

B2BAPIData Engineering

iMessage infrastructure for business

Artificial IntelligenceSaaSAPI

Research services for ChatGPT and Claude

Artificial IntelligenceAPIInfrastructure

Cosmic is an AI-powered headless CMS

Developer ToolsAPI

Developer friendly drop in payouts infrastructure

FintechPaymentsAPI

Make your LLMs 3x faster.

Artificial IntelligenceDeveloper ToolsSaaS

The essential platform for modern medical practices and patients.

HealthcareTelemedicineAPI

A single point integration for secure and automated EV charging.

Artificial IntelligenceAPIEnergy

Real-time speech translation

Generative AIAPITelecommunications

Finch is the Employment Data Platform

FintechHR TechAPI

Generate fast, reliable APIs for any platform

Developer ToolsB2BAPI

Bring AI to life with the world's best interactive avatars

Artificial IntelligenceDeveloper ToolsSaaS

Kugel is an on-prem Voice AI model supporting 30+ languages

Generative AIAPIConversational AI

Email API service.

AI Agent for Billpay platforms to pay invoices with virtual cards

Open-Source Platform for Healthcare Data Intelligence

B2BDigital HealthHealthcare

Modern Treasury

Payment operations tools for money movement.

Fast Models Optimized for Coding Agents

Artificial IntelligenceDeveloper ToolsGenerative AI

Video infrastructure for developers

Developer ToolsVideoAPI

GraphQL API to connect all of the internet's APIs. Join us at Netlify!

Customer Context for Agents

Artificial IntelligenceB2BAPI

Turning America’s supply chain inefficiency into infrastructure.

B2BAPISupply Chain

Turning messy inboxes into ERP-Ready Data

APISupply ChainInfrastructure

Build an API to interact with any website.

Developer ToolsAPIBig Data

Our mission is to make Voice AI accessible and useful to all.

Generative AIAPI

Intelligent Personal Cloud Storage

Generative AIConsumerAPI

Deploy Machine Learning Models with One Command

AIOpsArtificial IntelligenceMachine Learning

AI documentation engineer – test & autoimprove stale product docs

Artificial IntelligenceDeveloper ToolsB2B

Fullstack API and management platform for dashboards and reporting

SaaSAnalyticsAPI

The API to get recordings, transcripts, and metadata from meetings

The open source Postman alternative.

Developer ToolsOpen SourceAPI

Run any coding agent harness in the cloud

Artificial IntelligenceDeveloper ToolsSaaS

Open-Source Postman alternative

Developer ToolsSaaSOpen Source

Same day local delivery, via API. Currently operating in SF.

DeliveryLogisticsAPI

API for unlimited, durable, real-time streams

Developer ToolsOpen SourceAPI

Guardrails to validate your agent's actions before they execute

Developer ToolsB2BAPI

The Universal API

Showing 48 of 63 Filter the directory by this slice →

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2 of 4 similar companies are hiring right now · most common: Engineering

communication for agents

Developer ToolsAutomationEmail

Extend cloud sandboxes with iOS, Android and more

Artificial IntelligenceB2BEnterprise Software

A complete DevOps platform delivered as a single application.

Developer ToolsDevSecOpsOpen Source

Email for developers

EmailDeveloper InfrastructureSaaS

All startups in San FranciscoEvery tag "API" startups nationwideEvery city "Artificial Intelligence" startups in San Francisco606 startups "AI" startups in San Francisco572 startups "B2B" startups in San Francisco520 startups "SaaS" startups in San Francisco428 startups "Developer Tools" startups in San Francisco307 startups "Fintech" startups in San Francisco180 startups "Generative AI" startups in San Francisco137 startups "Consumer" startups in San Francisco120 startups

Frequently asked questions

How many "API" startups are in San Francisco?

Our index currently tracks 63 active tech startups in San Francisco tagged "API". Counts move as scrapers discover new companies and flag shutdowns inactive.

Which "API" startups are based in San Francisco?

Companies on this page include Alpaca, Checkr, and Deepgram, plus 60 more below. Each profile links to the company's site and any open roles we scrape.

How is this different from the San Francisco startups page or the "API" tag page?

/startups/location/san-francisco lists every indexed startup in San Francisco across tags. /startups/tag/api lists every "API" startup nationwide. This page is the intersection — only companies that resolve to both San Francisco and "API".

Are these San Francisco "API" startups hiring?

7 of the 63 companies on this page currently have open roles in our jobs index.

How often is this list updated?

Automated scrapers refresh on the same daily cadence as the rest of the directory. The last index update was 2026-09-02.