Open Source API Tools
Discover 179 open source API repositories from GitHub, each with an analysis of what it does, key features, use cases and alternatives. API projects here are most often combined with Self Hosted, Python and TypeScript. Last updated October 4, 2026.
179 repositories · updated October 4, 2026
editly: Create Videos from Code and Media Clips
Editly is a Node.js command-line tool and JavaScript API for assembling videos from clips, images, titles, and audio. It suits creators and developers who want repeatable edits defined in code, with transitions and overlays rendered through ffmpeg.
openapi-servers: Expose Tools to AI Agents Through OpenAPI
openapi-servers provides FastAPI reference servers for connecting AI agents and workflows to external tools and data through standard REST APIs. Use its examples to build or host services such as filesystem, Git, weather, SQL, and RAG tools.
useSend: Send Transactional and Marketing Email
useSend is a self-hostable email platform built on Amazon SES, with a dashboard and APIs for transactional and marketing email. It suits teams seeking an alternative to hosted email services who are prepared to operate the supporting infrastructure.
flask-restful: Build REST APIs with Flask
Flask-RESTful is a Python framework that provides building blocks for creating REST APIs with Flask. It suits developers who want an API-focused structure for Flask applications; consult its documentation for setup and usage details.
FinRL-Trading: Build and Deploy Quantitative Trading Strategies
FinRL-Trading is a modular Python system for developing, backtesting, and executing quantitative trading strategies. Its shared portfolio-weight interface connects strategy components to backtests and Alpaca trading, making it useful for researchers and practitioners evaluating end-to-end workflows.
instructor: Extract Validated Structured Data from LLMs
Instructor is a Python library that turns LLM responses into validated, typed data using Pydantic models. It suits applications that need reliable extraction across supported model providers without writing custom parsing and validation flows.
matterbridge: Connect Chats Across Messaging Platforms
Matterbridge relays messages between channels on many chat platforms, so communities can communicate without moving everyone to one service. It suits administrators who need to connect existing chat systems through configurable gateways.
claude-code-proxy: Connect Claude Code to OpenAI and Gemini
A Python proxy lets Anthropic-compatible clients such as Claude Code use OpenAI, Gemini, or direct Anthropic backends. It translates requests and responses through LiteLLM, with configurable model mappings and provider selection.
AnyCrawl: Crawl Websites and Extract LLM-Ready Data
AnyCrawl is a TypeScript toolkit for scraping individual pages, crawling sites, processing batches of URLs, and extracting structured data with LLMs. It suits developers building data pipelines for AI applications who need browser rendering or parallel processing.
OpenSign: Create and Manage Electronic Signatures
OpenSign is a self-hostable document-signing platform for creating, sending, and tracking electronic signatures on PDFs. It supports multiple signers, reusable templates, audit trails, and API integrations.
text-extract-api: Extract Text and Data from Documents
A self-hostable API that turns PDFs, images, and Office files into Markdown or structured JSON using OCR and Ollama models. It suits teams that need document processing and PII removal with control over where files are processed.
Notify: Send Email and SMS Notifications from ASP.NET Core
Notify is an ASP.NET Core notification service for sending email and SMS through REST APIs or messaging. It combines MongoDB persistence with background processing and supports multiple SMS providers.