API AI Startup Jobs

API-first stock/ETF/crypto brokerage infrastructure for developers.

Enterprise voice AI platform offering Speech-to-Text, Text-to-Speech, and Voice Agent APIs for real-time and batch use, deployable in cloud or self-hosted.

Developer tools company that generates SDKs and documentation from API specifications.

Infinite canvas SDK for React enabling developers to build web-based whiteboards and collaborative visual experiences, powering products like ClickUp Whiteboards and Padlet Sandboxes.

Developer-first authentication and user management platform with embeddable UIs, APIs, and admin dashboards.

Health insurance data platform modernizing benefits data exchange between HR tech and carriers.

Messaging and chat API/SDK platform for scalable in-app communication.

Market-leading SaaS platform helping governments worldwide automate building permitting, inspection, licensing, planning, and community development with enterprise-grade cloud solutions.

Adaptive builds AI-native finance tooling to automate accounting and operations workflows for modern software and startup teams.

Allium is an enterprise-grade blockchain data platform that provides accurate, fast, and simple blockchain data across 100+ blockchains and 1000s of schemas, delivering historical and real-time data through interactive dashboards, APIs, and custom integrations for institutions and crypto enterprises.

Amenitiz offers an all-in-one hotel management platform for independent hoteliers, including booking, payments, and operations tools.

AppBrilliance offers a patented Money API that enables real-time, non-custodial payments through FedNow® and RTP®.

Life insurance technology platform helping carriers digitize products and distribution.

Cal.com is an open-source scheduling infrastructure platform that enables absolutely everyone to build scheduling into their applications, providing a flexible and customizable alternative to proprietary scheduling tools.

CapitalOS provides embedded spend management infrastructure for vertical SaaS platforms, enabling business credit and spend controls via API integrations for platform customers.

Chalk builds a real-time inference data platform that gives ML and AI teams low-latency feature computation, retrieval, and production orchestration for online decisioning workloads.

An embedded fintech company offering earned wage access loans through national bank Pathward, seamlessly integrating with payroll and HCM platforms.

Provides unified SDK and tools for connecting AI agents to SaaS APIs and secure credentials.

Convex is a backend-as-a-service platform for modern web applications, combining reactive databases, server functions, and auth-ready infrastructure.

Crypto-integrated business banking platform that uses stablecoin rails alongside traditional payment networks.

Double builds AI-native practice management software for accounting firms, combining bookkeeping workflows, task orchestration, and client operations into a single platform.

Crypto exchange infrastructure company behind Phoenix, a decentralized exchange on Solana.

Emergent is an AI app-building platform focused on no-code and agent-assisted product creation, helping users rapidly build real applications with AI.

Enode provides an API that connects energy devices like EV chargers, batteries, and solar systems for energy apps.

Fintech platform helping renters build credit through rental payment reporting to credit bureaus, reaching 228 million monthly active users through Zillow, valued at $1.2 billion

Builds encryption infrastructure for developers, including tokenization and PCI compliance tools for payments and sensitive data.

Meaning-based web search and crawling API powered by embeddings for AI applications.

Offers serverless GPU platform and APIs to run generative AI models with millisecond cold starts.

Developer infrastructure platform that automatically generates SDKs in multiple languages (TypeScript, Python, Go, Java, Ruby, C#, PHP) and interactive API documentation from API specifications, trusted by over 200 companies including Square, Webflow, ElevenLabs, and Intercom.

Firecrawl is a web data infrastructure platform that converts websites into clean, structured data optimized for AI applications through a simple API, turning entire websites into LLM-ready markdown or structured data.

Fish Audio develops multilingual AI voice generation and voice cloning infrastructure for creators and developers, with text-to-speech APIs and audio production tools.

Flora is a node-based AI design tool and infinite canvas platform for creative professionals. The platform allows designers to build and automate creative workflows using a visual node orchestration layer, enabling creation of images, videos, and other media assets. Used by designers at Alibaba, Brex, Pentagram, and Lionsgate.

Open-source financial infrastructure platform that provides programmable ledgers, payment connectivity, orchestration tools, and reconciliation services for building modern financial applications, trusted by companies like Booksy, Doctolib, Liberis, and Shares.

Gordian Software builds APIs that enable the world's leading travel organizations to increase revenue by seamlessly selling airline ancillaries and add-ons, serving over 60 million passengers monthly across 100+ airline partnerships.

AI-powered code review platform that provides complete codebase context to help development teams automate pull request reviews, bug diagnostics, and enhance development workflows with intelligent code understanding.

Griffin is an API-first UK bank providing a full-stack banking-as-a-service platform for companies that need regulated accounts and payments.

The developer platform for easily building reliable workflows with zero infrastructure, enabling serverless, event-driven backend workflows at scale.

Developer-first bug reporting tool that captures everything engineers need to debug in one click, including video replays, console logs, network requests, and reproduction steps.

Junction (formerly Vital) modernizes healthcare infrastructure with seamless lab testing and device data integration, connecting over 500 wearables and medical devices with 10+ lab networks including Labcorp and Quest across all 50 states.

CFTC-regulated prediction market exchange where users trade on real-world event outcomes across economics, politics, weather, and other markets.

Keep is an all-in-one finance and spend platform for Canadian businesses, combining corporate cards, bill pay, expense management, and accounting workflows in a single system.

Building the base layer for the agentic web, enabling autonomous AI agents to interact seamlessly across the internet.

Embedded accounting platform for SMB software companies, allowing platforms to offer complete accounting and AI-powered bookkeeping services directly within their products, fully replacing external tools like QuickBooks. Supports 30,000+ SMBs through platform customers including Moxie, Nav, Dripos, and Carry with 25%+ adoption rates.

Mangrove builds a decentralized exchange with an on-chain order book and programmable liquidity for DeFi traders and market makers.

Marqo is a vector search platform that enables developers to build smarter search experiences with multimodal AI, improving conversion rates for e-commerce, recommendations, and content discovery.

Mesh builds crypto payments infrastructure that lets merchants and fintech platforms accept digital assets while settling instantly in stablecoins.

Digital banking platform for banks and credit unions, spanning account opening and online/mobile banking.

Neon is a modern direct-to-consumer payment platform built specifically for mobile games, helping game publishers build branded digital stores and bypass costly app store fees while providing players with personalized experiences and publishers with higher profit margins.

Oneloop builds API authentication and security infrastructure for engineering teams, offering auth, API key management, rate limiting, and abuse prevention in a developer-first platform.

OpenRouter provides developers with seamless access to 500+ AI models through a single unified API, eliminating the need to rewrite code or renegotiate contracts for LLM integration.

Paid builds revenue infrastructure for AI agents, enabling results-based billing and monetization of autonomous AI services. Founded by Manny Medina (Outreach founder), the platform helps AI agent companies charge customers based on value delivered rather than traditional SaaS models.

PaleBlueDot AI develops an AI platform and infrastructure stack for building and deploying AI applications, including agent workflows and model-powered products.

Parallel builds web infrastructure for AI agents, providing APIs and tooling that let models search, browse, and interact with the live web more reliably.

Partly provides infrastructure and APIs for the auto parts industry, standardizing communication protocols and enabling automation across the supply chain for repairers, OEMs, and green suppliers.

API-first platform to source, purchase, and manage carbon credits and carbon removal at scale.

API-first loan management platform for lenders to automate servicing, payments, and compliance.

Construction permitting software simplifying permit preparation and submission process, known as the 'TurboTax for construction permitting' with automated workflows for contractors and developers.

Perplexity builds an AI-native answer engine and assistant that combines web retrieval with large language models for consumer and enterprise search workflows.

Payroll connectivity APIs for direct deposit switching, income and employment verification, and earned wage access.

Playbook is a creative file manager designed specifically for designers, serving as a beautifully organized cloud storage and sharing platform. The platform uses image tagging technology to transform files into expressive Pinterest-style galleries, making it easy for designers to store, organize, and share their creative work.

Leading 3D scanning and capture platform for iOS, Android, and web with LiDAR technology, photogrammetry, and 360° capabilities for creating professional-grade 3D models and floor plans.

Energy-efficient AI inference hardware company building custom chips optimized for transformer models. Atlas systems deliver 3.5x better performance-per-dollar than NVIDIA H100, and next-gen Asimov silicon targets 2TB memory per accelerator for production in 2027.

Prismic is a headless CMS and page builder designed for modern web development, enabling marketing teams to create pages independently while developers maintain control using frameworks like Next.js, Nuxt, and SvelteKit.

API-first Document AI that converts PDFs, images, slides, and spreadsheets into structured JSON for RAG, analytics, and automation.

Railway offers a cloud deployment platform that helps engineering teams ship and operate applications and databases with minimal infrastructure overhead.

Resend provides an email API and deliverability platform built for developers to send and manage transactional and marketing email.

AI voice platform enabling businesses to build and deploy AI-powered voice agents for phone operations, contact centers, and customer service. API-driven solution with natural, low-latency conversations and multilingual support.

Runware provides a unified AI API platform that aggregates 300+ model classes and hundreds of thousands of AI model variants behind a single consistent schema, delivering up to 10x better price and performance for generative AI applications.

Unified API platform that connects business data across commerce, accounting, and payments platforms, enabling B2B SaaS companies to integrate financial data seamlessly.

Shovels builds construction intelligence software that turns fragmented building permit data into actionable market and go-to-market signals through APIs and analytics tools.

Sling Money is a stablecoin-based global payment app that uses modern real-time payment systems, the Solana blockchain, and reserve-backed stablecoins to enable nearly instant and extremely low-cost transfers across 75+ countries, with all transfers currently fee-free.

Speakeasy is a complete API development platform that polishes OpenAPI, generates production-ready SDKs and Terraform providers, and builds MCP servers from OpenAPI documents with extensive customization options to connect LLMs to data wherever it lives.

StackOne provides a unified API platform for product teams to ship customer-facing integrations quickly across SaaS systems.

AI-powered data platform that transforms unstructured web data and documents (websites, PDFs, pitch decks, reports) into structured, enterprise-ready datasets using their proprietary DoRa model that navigates and extracts data like a human, enabling real-time web extraction for business intelligence and data workflows.

Succinct is making zero-knowledge proofs accessible to any developer through SP1, their zkVM, and decentralized prover network that enables scalable blockchain applications and cryptographic infrastructure.

Supabase is an open-source backend-as-a-service platform offering managed PostgreSQL, authentication, real-time subscriptions, and storage for web and mobile developers:contentReference[oaicite:24]{index=24}.

Synthflow provides a no-code voice AI platform for building and deploying production phone agents for customer support, sales, and operations workflows.

Search engine for LLMs and RAG connecting AI agents to real-time web with APIs for search, crawling, and structured insights extraction

TinyFish provides enterprise web agents that automate complex web-based workflows and extract structured data from websites at scale. The platform enables Fortune 500 companies like Google and DoorDash to automate web interactions, streamline data collection, and integrate web automation into their business processes.

Tollbit provides a content monetization platform that enables websites to protect and monetize their content by allowing AI bots and data scrapers to pay for licensed access, creating a sustainable content ecosystem.

Trace builds voice AI infrastructure for financial-service customer interactions, focusing on call automation and support workflow execution.

Consumer-permissioned data platform that provides API access to payroll, employment, and financial data for streamlined income and employment verification, asset verification, and direct deposit switching.

TwelveLabs builds multimodal foundation models that understand, index, and search video content for developers and enterprises.

Vapi is building the leading developer platform for conversational voice AI agents, abstracting away the complexity of building these agents and managing real-time infrastructure to enable enterprise-ready voice AI solutions across finance, healthcare, travel, and other industries.

Vectara provides a retrieval-augmented generation platform with enterprise search, grounded generation, and evaluation tooling to help teams build production-grade generative AI assistants.