All APIs

Observability, Errors & ReplayRollbar

Rollbar

Event Reporting, Deployment Tracking API Focuses on real-time error monitoring and aggregation, providing efficient alert automation. Target Users: Dev teams needing to fast identify and fix errors.

Marketing, Email & PushKlaviyo

Klaviyo

Marketing Automation API, Behavior Data Driven. Deep e-commerce integration, customer behavior-based personalization.

Marketing, Email & PushOneSignal

OneSignal

Mobile/Web Push API, Email, SMS Integration, Customer Journey Orchestration. Cross-channel engagement leader, powerful real-time segmentation.

Maps, Geolocation & PlacesFoursquare / Factual

Foursquare / Factual

Places API (POI Data), Location Intelligence REST API Target Users: Applications needing rich, accurate business location data and context-aware data.

Internationalization & Compliancei18 connection

i18 connection

AI-driven Translation, Central String Management, Deep Integration with i18n Libraries REST API & CLI Target Users: Fast deployment of multi-language apps, teams needing centralized translation asset management.

Financial Markets & TradingNASDAQ Data Link (formerly Quandl)

NASDAQ Data Link (formerly Quandl)

Extensive Alternative Data and Traditional Financial Datasets REST API Target Users: Professional researchers, quant strategy developers, applications needing diverse and specialized datasets.

Financial Markets & TradingFinnhub

Finnhub

Real-time Market Data, Company Fundamentals, Analyst Estimates, Earnings Call Transcripts REST API & WebSocket Target Users: Applications needing deep fundamental data and alternative data.

Financial Markets & TradingAlpha Vantage

Alpha Vantage

Real-time & Historical Stock, Forex, Crypto, Economic Indicators, Technical Analysis REST API Target Users: Junior developers, academic research, applications needing wide data coverage (provides free tier).

Financial Markets & TradingMassive (original Polygon.io)

Massive (original Polygon.io)

Real-time & Historical Stock, Forex, Crypto Data, Company Fundamentals REST API & WebSocket Target Users: Data analytics platforms, HFT, applications needing low latency, high reliability data.

Financial Markets & TradingTrader API

Trader API

Trading (Stocks, Options, ETFs), Market Data, Account Management REST API Target Users: Focuses on developers and investment platforms, providing complete brokerage service interface.

Financial Markets & TradingAlpaca API

Alpaca API

Algo Trading, Commission-free Stock & Crypto Trading, Brokerage as a Service (BaaS) REST API & WebSocket Target Users: Fintech apps, Robo-advisors, Algo trading developers.

eCommerce & MarketplacesEtsy API

Etsy API

Shop Info, Listings, Order Management (Focus on Handmade/Vintage) REST API Target Users: Tools serving Etsy creators and independent sellers.

Documents, PDFs & eSignatureDropbox Sign API

Dropbox Sign API (原 HelloSign)

Embedded Signing, Template Creation, Signature Requests REST API Target Users: Integrating Dropbox ecosystem, seeking simple, developer-friendly interface apps.

eCommerce & MarketplacesBigCommerce API

BigCommerce API

Store Management, Catalog, Checkout REST API Target Users: Scalability-focused mid-to-large e-commerce.

Documents, PDFs & eSignatureAnvil API

Anvil API

PDF Generation, Web Forms, E-signature All-in-one Workflow REST API Target Users: Applications processing online document form filling and subsequent signature flows.

Documents, PDFs & eSignaturePDF Generator API

PDF Generator API

PDF Generation based on JSON Data and Templates REST API Target Users: Needing to dynamically generate invoices, reports, contracts from data.

Documents, PDFs & eSignaturePDF.co API

PDF.co API

PDF Extraction (OCR), Conversion, Form Filling, Data Automation REST API Target Users: Applications needing to extract structured data from PDF documents and process complex forms.

Documents, PDFs & eSignatureApryse (PDFTron) SDK/API

Apryse (PDFTron) SDK/API

PDF Editing SDK, Document Viewing, Annotation, Conversion, Creation SDK & REST API Target Users: Developers needing to embed complete PDF functionality into web/desktop/mobile apps.

Documents, PDFs & eSignatureSignNow API

SignNow API

E-signature, Document Workflow Automation, Cloud Document Management REST API Target Users: Seeking easy-to-use and integrated cloud e-signature solutions.

Documents, PDFs & eSignatureAdobe Acrobat Sign API

Adobe Acrobat Sign API

E-signature, Document Tracking, Deep Integration with Adobe Ecosystem REST API Target Users: Adobe product users, enterprises needing high trust and global standards.

Auth, Identity & KYCID.me

ID.me

Identity Verification combined with Digital Wallet, MFA. Specific advantages in US Public Services and Healthcare.

Documents, PDFs & eSignatureiLoveAPI (iLovePDF)

PDF Merge, Split, Compress, Convert (Word/Excel/Image)

REST API Target Users: Applications needing Simple, Efficient, High-volume PDF Task Processing.

Scheduling & Calendarstimekit

Complex Scheduling Logic, Real-time Availability

REST API Target Users: Booking Systems needing High Flexibility and Complex Business Rules (e.g., Healthcare, Consultants).

Auth, Identity & KYCPersona

Persona

Fully Customizable Verification Flow and UI/UX. High brand control, flexible workflow orchestration.