Best tools for API Integration

Context retrieval layer for AI agents and RAG

Airweave is an open-source context retrieval platform that connects AI agents and RAG systems to 50+ apps and databases through a unified search interface. It continuously syncs data from sources like Notion, Slack, GitHub, and databases, making it searchable through LLM-friendly APIs. Airweave includes Python and TypeScript SDKs, MCP support, and a CLI for managing data connections.

Open-source platform for building API integrations

Nango is an open-source API integration platform that handles OAuth authentication, data synchronization, and proxying for 700+ APIs in a single self-hostable package. It manages token refresh, rate limiting, field mapping, and webhook syncing so developer teams can connect AI agents and products to external services in hours instead of weeks. Backed by Y Combinator W23 with $7.5M in funding.

Voice AI APIs for speech-to-text and text-to-speech

Deepgram is a voice AI infrastructure platform providing low-latency speech-to-text, text-to-speech, and conversational AI APIs. Its Nova-3 model delivers industry-leading accuracy for real-time transcription with streaming support, interruption handling, and multi-language capabilities. Used by 1,300+ organizations including Twilio and Vapi, Deepgram powers voice features in applications ranging from call centers to AI agent voice interfaces.

OpenAI API management gateway for 100+ LLM providers

One API is a self-hosted LLM API gateway that provides a unified OpenAI-compatible interface for managing multiple model providers including OpenAI, Azure, Anthropic, Google, and dozens of Chinese providers. It handles load balancing, quota management, rate limiting, token tracking, and channel-based routing through a web dashboard. Widely adopted in the Chinese developer ecosystem with over 18,000 GitHub stars.

YC-backed multimodal RAG platform for documents, images, and video

Morphik is a YC-backed multimodal RAG platform that ingests and retrieves information from documents, images, tables, and video content. It processes complex document layouts including charts, diagrams, and multi-column formats that traditional text-only RAG systems handle poorly. Provides API-first integration for building knowledge bases that understand visual as well as textual information.

AI chatbot framework for WeChat with multi-model and plugin support

chatgpt-on-wechat is an open-source framework for deploying AI chatbots on WeChat, the dominant messaging platform in China. It supports OpenAI, Claude, Gemini, Qwen, and local models through a plugin architecture. Features group chat management, image generation, voice messages, and knowledge base integration. Over 42,700 GitHub stars reflecting massive adoption in the Chinese developer community.

Alibaba's agent framework built for the Qwen model family

Qwen-Agent is Alibaba's open-source framework for building AI agents powered by the Qwen model family. It provides tool use, planning, memory, and multi-agent orchestration with native optimization for Qwen models including function calling and code interpretation. Supports RAG, browser automation, and custom tool development with over 15,900 GitHub stars.

Adaptive web scraping library with anti-bot evasion and smart selectors

Scrapling is a Python web scraping library that uses adaptive selectors and anti-bot evasion techniques to extract data from websites reliably. It generates selectors that survive website layout changes by understanding element context rather than relying on brittle CSS paths. Features stealth browser automation, automatic retry logic, and proxy rotation. Over 34,500 GitHub stars.

No-code AI web scraping platform with visual workflow builder

Maxun is a no-code web scraping platform that uses AI to extract structured data from websites through a visual workflow builder. Users point and click on the data they want to extract, and Maxun generates resilient scraping workflows that handle pagination, authentication, and dynamic content. Features anti-bot detection avoidance, scheduled runs, and API access for integration. Over 15,300 GitHub stars.

All-in-one embeddings database with RAG, search, and agent capabilities

txtai is a self-contained AI search and RAG platform that combines vector embeddings, semantic search, LLM pipelines, and agent workflows in a single Python library. It handles embedding generation, similarity search, extractive QA, summarization, translation, and custom pipelines without external dependencies. Runs locally with over 12,400 GitHub stars and Apache 2.0 license.

Git-friendly API client by the creator of Insomnia

Yaak is an API client built by the original creator of Insomnia, designed with Git-friendly file storage from the ground up. API requests, environments, and collections are stored as human-readable files that version control naturally alongside application code. Supports REST, GraphQL, gRPC, and WebSocket with a clean, keyboard-driven interface focused on developer productivity.

MIT-licensed API documentation framework by Zuplo

Zudoku is an MIT-licensed API documentation framework built by the team behind Zuplo API gateway. It generates developer portals from OpenAPI specs with features like interactive API playground, markdown content pages, authentication integration, and search. Designed as a free alternative to ReadMe and Stoplight with customizable themes and plugin architecture.

Modern API documentation platform and OpenAPI reference generator

Scalar is an API documentation platform that generates beautiful, interactive API references from OpenAPI specifications. Selected as the default API docs renderer in .NET 9, it replaces Swagger UI with a modern interface featuring dark mode, request examples in multiple languages, and a built-in API client. Available as open-source packages for any framework or as a hosted platform.

AWS open-source SDK for building model-driven AI agents

Strands Agents is an open-source SDK from AWS that takes a model-driven approach to building AI agents. Developers define a prompt, model, and tools, and the LLM handles planning and orchestration autonomously. Supports Amazon Bedrock, Anthropic, OpenAI, Gemini, Ollama, and more. Powers Amazon Q Developer and AWS Glue in production. Available in Python and TypeScript with native MCP support.

Kotlin-native AI agent framework by JetBrains with MCP support

Koog is JetBrains official Kotlin-native framework for building predictable, fault-tolerant AI agents. It provides structured agent workflows with MCP protocol support, type-safe tool definitions, and deterministic execution patterns designed for JVM production environments. As the first production-grade Kotlin agent framework, it fills the gap in a JVM ecosystem dominated by Python-based alternatives and integrates naturally with existing Kotlin and Java backend infrastructure.

Production RAG engine with hybrid search and knowledge graphs

R2R is a production-grade RAG engine from SciPhi AI that combines hybrid search with knowledge graph extraction and agentic retrieval capabilities. It provides a complete pipeline from document ingestion through retrieval and generation, supporting vector, keyword, and graph-based search strategies. The managed API and self-hosted options make it accessible for both rapid prototyping and production deployments requiring advanced retrieval beyond simple vector similarity.

RAG-based document QA with multi-user support and agent reasoning

Kotaemon is an open-source RAG-powered document question-answering interface backed by Cinnamon AI. It supports multi-user workspaces with access controls, advanced retrieval pipelines including hybrid search and knowledge graph extraction, and agentic reasoning for complex multi-step queries. The web UI handles PDFs, Office documents, and images with citations pointing to exact source passages, making it suitable for both individual research and team knowledge management.

Browser automation CLI built for AI agents by Vercel Labs

Agent Browser is a Rust-based browser automation CLI designed specifically for AI agent workflows rather than traditional testing. Developed by Vercel Labs, it provides semantic element selection through a refs system, accessibility tree snapshots, session persistence, and authentication vaults. Unlike Playwright or Puppeteer which target test automation, Agent Browser optimizes for token efficiency and deterministic element selection that gives LLMs reliable browser interaction capabilities.

Open-source general AI agent framework from the MetaGPT team

OpenManus is an open-source framework for building general-purpose AI agents, developed by core contributors from the MetaGPT community. It provides a modular architecture with planning agents, reactive agents, and tool-calling agents that can execute code, browse the web, search for information, and handle files. Built as the open alternative to Manus AI, it gained over 55,000 GitHub stars and supports multi-agent collaboration with real-time execution feedback.

Email API service that gives AI agents their own inboxes and identities

AgentMail is a YC S25 startup that provides email infrastructure specifically designed for AI agents. It gives each agent its own email address and inbox, enabling agents to send, receive, and manage email conversations independently. With $6 million in seed funding from General Catalyst and Paul Graham, and over 500 B2B customers, AgentMail solves the identity and communication gap that arises when organizations deploy autonomous agents that need to interact via email.

AI-native API gateway by Alibaba with MCP server hosting and LLM routing

Higress is an open-source AI-native API gateway developed by Alibaba that combines traditional API management with LLM-specific capabilities like token-based rate limiting, model routing, prompt caching, and MCP server hosting. Built on Envoy and Istio, it provides enterprise-grade traffic management while natively understanding AI workload patterns including streaming responses, long-lived connections, and multi-model fallback chains.

Open-source financial data platform for quants, analysts, and AI agents

OpenBB is an open-source financial data platform that normalizes data from 100+ providers into a unified Python SDK, REST API, and Excel Add-in. It serves as the open-source alternative to Bloomberg Terminal for developers building fintech applications, quantitative research pipelines, and AI-powered financial analysis tools. With over 65,000 GitHub stars and SOC 2 Type II certification, it is one of the most popular open-source developer tools for financial data.

Behavioral control layer for reliable customer-facing AI agents

Parlant is an open-source framework that adds behavioral governance to conversational AI agents. Instead of relying on prompt engineering alone, it lets teams define explicit policies, conversation guidelines, and behavioral rules that agents follow predictably across multi-turn interactions. Parlant sits between the LLM and the user-facing interface, enforcing consistent agent behavior for customer support, sales, and service automation use cases.

Hunt down social media accounts by username across 400+ platforms

Sherlock is a Python CLI tool that searches for a given username across 400+ social networks and websites simultaneously. It is widely used in OSINT investigations, security audits, red teaming exercises, and digital footprint analysis. Sherlock is included in Kali Linux and Parrot Security distributions and has over 76,000 GitHub stars, making it one of the most popular open-source security tools.