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
authkit: Add Hosted or Custom Authentication to Your App
AuthKit is a WorkOS authentication example project showing how to use a hosted sign-in experience or build a custom UI with headless User Management APIs. It is aimed at developers adding WorkOS-backed authentication to an application.
ch.at: Chat with Language Models over Web, SSH, and DNS
ch.at is a lightweight Go chat service that exposes language-model conversations through a web page, HTTP API, SSH, and DNS. It also offers a public, in-memory board for posts and feeds, making it suited to simple, low-dependency deployments and experimental access methods.
QueryWeaver: Turn Natural-Language Questions into SQL
QueryWeaver converts plain-English questions into SQL by using a graph representation of database schemas. It suits teams that want a self-hosted Text2SQL web app, REST API, MCP interface, or Python SDK for PostgreSQL and MySQL.
LocalAI: Run AI Models on Your Own Hardware
LocalAI serves language, vision, audio, and image models through compatible APIs on local or distributed hardware. It suits developers and teams who want a flexible self-hosted AI service without depending on a GPU.
logto: Build Authentication and Authorization for Apps
Logto is an identity platform for SaaS and AI applications, built around OIDC and OAuth 2.1. It provides sign-in flows, multi-tenancy, enterprise SSO, and authorization capabilities for teams building user-facing apps and APIs.
favicon-downloader: Find and Download Website Favicons
favicon-downloader is a TypeScript web tool for finding and downloading a site's available favicon sizes. It also provides HTML snippets and an API that retrieves icons from web pages and favicon services.
citadel: Analyze Windows Payloads and Malware Samples
Citadel is a self-hosted framework for static analysis of Windows payloads and malware samples. It combines PE parsing, capability mapping, and sample similarity analysis in a web interface for malware researchers and red teams.
defguard: Manage Secure VPN and Identity Access
Defguard is a self-hosted platform for managing WireGuard VPN access, identity, and multi-factor authentication. It suits organizations that want centralized control over network access and authentication inside their own infrastructure.
infinity: Serve Embedding and Reranking Models via API
Infinity is a Python serving engine for text embeddings, reranking, and selected image, audio, and late-interaction models. It provides an OpenAI-aligned REST API with multiple inference backends for teams deploying models from Hugging Face.
agent-service-toolkit: Build and Serve LangGraph Agents
A Python starter toolkit that connects LangGraph agents to a FastAPI service, reusable client, and Streamlit chat interface. It suits developers who want an end-to-end foundation for building, testing, and customizing agent applications.
typesense: Build Fast, Typo-Tolerant Search Experiences
Typesense is a C++ search engine for adding low-latency, typo-tolerant search to applications. Use it when you want a straightforward, self-hostable alternative to hosted search services, with options for filtering, faceting, vector search, and clustering.
novu: Send Product and Agent Communications Across Channels
Novu provides a unified API and conversation model for product notifications and agent messaging. Use it to coordinate delivery across channels such as email, SMS, push, chat, and in-app inboxes without integrating each channel independently.