Best tools for Full-Stack Development

Fork, customize, and ship AI agents on Vercel in minutes

Open Agents is a Vercel Labs open-source template for building and deploying cloud-hosted AI agents. It provides a production-ready Next.js starter with built-in tool use, streaming responses, multi-model support, and deployment on Vercel infrastructure. Developers can fork, customize agent behavior and tools, then ship agent-backed apps in minutes with automatic scaling and edge routing.

LangChain-powered agent harness with planning and subagents

Deep Agents is a production-ready agent framework built on LangChain and LangGraph for complex agentic workflows. It features a planning system for task decomposition, a filesystem backend for persistent operations, sandboxed shell execution, and isolated subagents with independent context windows. Automatic context summarization keeps agents coherent across long sessions, while smart defaults simplify prompt engineering for multi-step autonomous tasks.

Customer engagement infrastructure for developers

Knock is flexible notification and customer engagement infrastructure built for developers and AI agents. Send messages across email, SMS, push, chat, and in-app channels from a single API. Features AI-native journey building with single-prompt workflows, advanced segmentation with dynamic attributes, in-app messaging with custom components, data unification across warehouse and CDP, and version control with rollbacks. Delivers hundreds of millions of messages monthly with 99.99% uptime.

ML experiment tracking and model monitoring

Weights and Biases is the AI developer platform for experiment tracking, model monitoring, and ML workflow orchestration. Weave extends W&B with LLM ops capabilities for prompt engineering, evaluation, and deployment. Enables teams to track experiments, monitor model performance in production, manage datasets, log LLM application traces, and collaborate on ML projects with visualization dashboards, automated logging, and enterprise SSO and RBAC compliance.

Security operations resilience for SOC teams

Fig provides a Security Operations Resilience platform designed for modern SOC teams facing both unplanned and planned changes. Features drift detection to catch unplanned infrastructure changes, automated drift repair with testing, planned change modeling to simulate initiatives before deployment, version control, and automatic deployment with rollbacks. Helps teams maintain security coverage while shipping risk-free at 10x speed and focusing on strategic cyber work.

Cloud browser infrastructure for AI agents

Anchor Browser provides secure cloud-managed browser infrastructure for computer-use agents. Deploy humanized Chromium instances that access any website while maintaining bot-detection evasion and authentication support. Features OmniConnect for authentication lifecycle management, Web Action Cache for deterministic workflows, and built-in VPN infrastructure. Includes free tier and paid plans supporting millions of concurrent browser sessions for scalable agent automation.

Production-ready React Suspense and error handling

TypeScript library extending React Suspense API with declarative components and hooks for production applications. Provides ErrorBoundary with selective error catching via shouldCatch, SSR-safe Suspense with clientOnly prop, Delay component preventing loading flashes, ErrorBoundaryGroup for coordinated resets, and data fetching components including SuspenseQuery and SuspenseInfiniteQuery. MIT licensed by Toss with three years of active development.

Task runner for Python with Poetry and uv

Poethepoet (poe) is a batteries-included task runner for Python projects that integrates with Poetry and uv package managers. Define tasks in pyproject.toml, compose them in sequential, parallel, or DAG workflows, and execute with full virtual environment context. Supports shell commands, Python scripts, environment variables, .env file loading, and auto-generated shell completion across bash, zsh, and fish for streamlined development workflows.

AI testing and evaluation for agents and LLM apps

RagaAI Catalyst is a comprehensive Python SDK for observability, monitoring, and evaluation of LLM and agentic applications. Provides agent tracing with execution graph visualization, self-hosted dashboard with analytics, synthetic data generation, multi-metric evaluation framework, and guardrail management. Built for teams running production RAG systems and AI agents who need systematic testing, debugging, and performance optimization workflows.

Enterprise RAG framework by Tencent

WeKnora is a Tencent-developed LLM-powered knowledge management and Q&A framework for enterprise document understanding and semantic retrieval. Supports 10+ document formats including PDF, Word, Excel, and images with seamless IM platform integration for WeCom, Feishu, Slack, and Telegram. Offers Quick Q&A mode using RAG pipelines and Intelligent Reasoning mode with ReACT agents for complex multi-step reasoning tasks across organizational knowledge bases.

ByteDance high-performance JSON library

Sonic is ByteDance's blazingly fast JSON serialization library accelerated by JIT compilation and SIMD instructions. It achieves 3x faster throughput than Go's standard library while using 75% less memory and 99% fewer allocations. Drop-in compatible with encoding/json, it handles both simple Marshal/Unmarshal operations and streaming APIs for high-throughput services processing millions of events.

Fast embeddable vector search engine

USearch is a high-performance vector search engine implementing HNSW algorithms for approximate nearest neighbor queries across C++, Python, JavaScript, Rust, Java, Go, and more. It supports user-defined distance metrics, memory-mapped persistence for datasets larger than RAM, and filtered search with predicates. Used by YugabyteDB and ScyllaDB as their production vector indexing backend.

Open-source i18n and translation platform

Tolgee is an open-source internationalization platform that enables in-context translation directly within applications. Translators hold ALT and click any element to edit strings inline without touching code files. It integrates machine translation from DeepL, Google, and AWS, with SDKs for React, Angular, Next.js, Vue, and Svelte. Self-hostable for data sovereignty with granular team permissions.

Open-source observability for AI agents

Laminar is an open-source observability platform for AI agents providing tracing, evaluation, and analytics for LLM applications. It integrates with Vercel AI SDK, LangChain, OpenAI, and Anthropic with a single line of code. Features include OpenTelemetry-native SDKs, an extensible evaluation framework with CI/CD support, SQL access to traces and metrics, and a visual debugging timeline for agent reasoning and actions.

Open-source auth infrastructure for modern apps

Logto is an open-source authentication and authorization platform built on OIDC and OAuth 2.1, serving as an alternative to Auth0, Cognito, and Firebase Auth. It provides pre-built sign-in flows with customizable UI, social login, Google One Tap, MFA, enterprise SSO via SAML, and role-based access control. SDKs cover 30+ frameworks including React, Next.js, Vue, Flutter, Go, and Python, with multi-tenancy support for SaaS applications.

Open-source feature flag management platform

Unleash is the largest open-source feature flag platform, enabling teams to decouple deployment from release with gradual rollouts, A/B testing, and trunk-based development. It provides 15+ official SDKs for server and client frameworks, a web-based admin dashboard for managing feature toggles, and supports activation strategies like percentage rollout, user targeting, and environment-based rules. Self-hostable via Docker with PostgreSQL storage.

Open-source visual regression testing tool

Lost Pixel is an open-source visual regression testing tool that serves as an alternative to Percy and Chromatic. It captures and compares screenshots of UI components and application pages across Storybook, Ladle, Histoire, and custom screenshot sources like Cypress or Playwright. Integrated directly into GitHub Actions pipelines, it detects unintended visual changes before they reach production, with a free SaaS tier available for open-source projects.

CLI token usage tracker for AI coding agents

Tokscale is a CLI tool that tracks token usage and costs across AI coding agents including Claude Code, Codex, OpenCode, Gemini CLI, Cursor, and more. Built with a native Rust core for high-performance processing, it provides detailed breakdowns of input, output, cache, and reasoning tokens with real-time pricing calculations via LiteLLM data. Features include interactive 2D/3D contribution graphs, web visualization dashboards, global leaderboards, and JSON export for cost analysis.

AI red teaming and infrastructure security scanner by Tencent

AI-Infra-Guard is Tencent's open-source AI security platform providing one-click evaluation of AI infrastructure risks across five modules. It covers insecure config detection, multi-agent workflow evaluation, MCP server scanning across 14 risk categories, vulnerability scanning for 55+ AI frameworks with 1,000+ CVE mappings, and jailbreak evaluation for prompt robustness. Deployable via Docker with academic backing from Peking and Fudan Universities.

Build native Node.js addons in Rust via Node-API

napi-rs is a framework for building compiled Node.js native addons in Rust through the Node-API interface, eliminating node-gyp and C++ toolchains. It provides async/await with Promise integration, extensive type mappings between Rust and JavaScript, and cross-compilation to Windows, macOS, Linux, FreeBSD, and Android across x64, ARM, and RISC-V. Used by major JS tooling projects, napi-rs enables Rust-speed performance in Node.js apps.

In-process vector database — the SQLite of vector DBs

Zvec is an open-source in-process vector database from Alibaba designed as the SQLite of vector search. It runs as an embedded library directly inside applications without requiring external servers, delivering 8,000+ QPS with high recall rates. Zvec supports dense and sparse embeddings, multi-vector queries, and combined semantic plus structured filtering. Built on Alibaba's proven Proxima engine, it provides a lightweight alternative to server-based vector databases for local AI workflows.

Knowledge graph memory engine for AI agents

Cognee is an open-source knowledge engine that builds persistent memory for AI agents by combining vector search with graph databases. It ingests data from 38+ source formats, structures information into a knowledge graph with embeddings, and enables semantic and relational queries through its ECL pipeline. Its cognitive science-inspired architecture provides superior cross-document entity identification compared to traditional RAG approaches.

Official Vue.js language tooling and IDE support

Volar is the official Vue.js language tooling framework delivering advanced IDE support for Vue single-file components. It provides real-time TypeScript type inference in templates, intelligent autocompletion for components, props and slots, plus diagnostics from the Vue compiler. Volar powers the official Vue VSCode extension with 7M+ installs. Its core Volar.js layer is framework-agnostic, enabling language servers for other frameworks. MIT licensed with 13K+ stars.

Rust-powered JavaScript bundler for Vite

Rolldown is a high-performance JavaScript and TypeScript bundler written in Rust, built as the next-generation bundler for Vite. Created by Evan You and VoidZero, it offers a Rollup-compatible plugin API with 10-30x faster builds. It combines esbuild-level speed with full Rollup ecosystem compatibility, supporting tree-shaking, code splitting, and advanced optimizations natively. With 13K+ stars and MIT license, it is set to become the default bundler for Vite 8.