Open-source developer tools
Every listing tagged open-source, A to Z: 128 tools across 7 categories. Listed in alphabetical order, not ranked.
Agensh
Microsoft's open-source (MIT) multi-agent harness with no central orchestrator: agents claim sub-tasks, share findings, verify results and merge progress through a shared workspace, with experiment scripts and a reproduction guide.
agent-relay
Open-source (MIT) relay that lets coding sessions from different vendors work together, tested with Claude Code and Codex: one session leads, the other follows, the relay passes each turn across, records it on your disk and stops when something needs your decision, with a web console to watch and answer. macOS, Python 3.11+.
agent-usage-guard
Claude Code mod that reads your plan's 5-hour and weekly usage and holds subagent fan-out, heavy-context prompts and retry loops before they spend your window, asking in Claude Code's own dialog. Local only, no network; MIT licensed.
Agentic Resource Registry
Self-hosted, open-source (Apache-2.0) registry for sharing a team's coding agent resources (skills, agent files, MCP servers) with usage insights; works with Claude Code, Kiro, Cursor, Codex, Pi and more through the observal CLI. Formerly Observal.
Argus
Open-source (MIT), self-hosted security operations platform: AI agents triage and investigate alerts with read-only tools, while response playbooks start in shadow mode, use reversible actions and can be approved from Slack.
Arize Phoenix
Arize's AI observability platform, source-available under the Elastic License 2.0: OpenTelemetry tracing through OpenInference for OpenAI, Anthropic, LangGraph, the Vercel AI SDK and more, with LLM evals, datasets, experiments and a prompt playground; runs locally, in Docker or on Kubernetes.
Armite
Local Azure emulator with a real identity plane and RBAC: Entra tokens, managed identity, ARM, Key Vault and Blob Storage behind one RBAC engine that returns 403 where Azure would, driven unmodified by az, the Azure SDKs and Terraform. Apache-2.0.
Aruma
Open-source (Apache-2.0) self-hosted backend for apps built on the official Firebase SDKs: one Go binary plus PostgreSQL 18 with an embedded dashboard, serving Auth, Realtime Database, Cloud Storage, Security Rules and a Firestore-compatible document database, so on supported setups you change the config file, not your app code. No Cloud Functions; Cloud Messaging, App Check and Remote Config are planned. Pre-1.0 (v0.4.0); run it with Docker Compose or a release binary.
arvre
Open-source (MIT) terminal UI that draws your Claude Code sessions and their forks as a tree or flowchart: move between parents and children, filter to this directory or the last 24 hours, and resume any session with claude --resume. It infers forks from shared message IDs because Claude Code records no parent link. Python 3.11+, pipx install arvre.
Auth.js
Open-source authentication library (formerly NextAuth.js) for web frameworks.
Axolotl
Free, open-source (Apache-2.0) fine-tuning framework: one YAML config covers dataset prep, training, evaluation and quantization. Full fine-tuning, LoRA, QLoRA, DPO, KTO, ORPO and GRPO on NVIDIA or AMD GPUs, multi-GPU with FSDP2 or DeepSpeed and multi-node with Torchrun or Ray.
Bifrost
Open-source (Apache-2.0) AI gateway from Maxim AI: one OpenAI-compatible API for thousands of models with failover, load balancing, semantic caching, virtual keys, budgets and an MCP gateway; Enterprise plan available.
Browser Use
Open-source (MIT) browser agent: run it from Python with any LLM, give Claude Code or Codex a browser through its CLI skill, or use Browser Use Cloud for stealth browsers with CAPTCHA solving and residential proxies and a hosted agent API. Pay as you go, no subscription: cloud browsers $0.02 an hour, $1 free credit.
Busabase
Open-source (MIT) database and workspace that acts as a system of record for AI agents: agents and people share data, docs, skills and apps, every change keeps its history, and important writes can wait for review; desktop, self-hosted or Busabase Cloud.
capo-s3
Typed, async-first Python SDK for Amazon S3 and S3-compatible storage (RustFS, MinIO, Cloudflare R2), with asyncio and trio support, a matching sync client, multipart transfers and presigned URLs. Part of capo, an MIT-licensed community alternative to boto3 built on its own HTTP stack.
CATT
Consumer Agent Testing Tool: open-source (MIT) Python CLI that runs a scripted or model-driven surrogate assistant (Muse or Instinct emulation, unaffiliated) against your MCP server, MCP app, website or HTTP API, checks what the service actually did and records sealed evidence you can replay and diff in CI.
Charter
Open-source (Apache-2.0) Python library for AI agents that act in your customers' accounts through APIs: each tool is a Pydantic model that mirrors the API field by field with your rules on top, every call is validated before it is sent, the customer a call is for comes from your app rather than the model, and the same declarations produce a reviewable map of everything each tool can reach. Runs in your process with no proxy or telemetry; works with any HTTP API. pip install charter-ai.
Chroma
Open-source (Apache-2.0) search infrastructure for AI: vector, full-text and metadata search. Self-host it or use serverless Chroma Cloud, billed per GiB written, stored and queried, with free credits to start.
Cloudflare Sandbox SDK
Open-source (Apache-2.0) SDK for per-user or per-task Linux sandboxes started from your Worker: each sandbox is a Durable Object plus a Container, a microVM with its own kernel and network, and @cloudflare/sandbox adds file streaming, S3 bucket mounts and directory backups to R2. Needs the $5 Workers Paid plan.
Corgi
Open-source (MIT) terminal and agent multiplexer for macOS, Linux and WSL: shows what each Claude Code, Codex, Pi or OpenCode agent is doing and which needs you, keeps sessions running in the background like tmux, and tracks worktrees, changed files and per-workspace resource usage.
Correct Hooks
Open-source (MIT) libraries for TypeScript, Python and Rust that sign and verify webhooks with ed25519 asymmetric signatures and handle key management and rotation; early-stage but usable.
Costura
Open-source (Apache-2.0), self-hosted AI spend attribution: imports read-only billing from OpenAI, Anthropic, Claude.ai, Codex, OpenRouter, Cursor and GitHub Copilot, attributes each dollar to a key, workspace and person, and ties totals out to each provider's report; in beta.
CrewAI
Open-source (MIT) Python framework for multi-agent automation: Crews of role-based agents that work one task together, and Flows for event-driven control that mix single LLM calls with Crews. Standalone, not built on LangChain. CrewAI AMP adds managed deployment, tracing and governance; free plan with 50 workflow executions a month.
Death Plan Switch
Free, MIT-licensed, self-hosted dead man's switch for solo developers: it emails you weekly and, if you stop checking in, asks your next of kin and then notifies the contacts who need to take over; PHP 8.1+, no database.
deCDN
Open-source peer-to-peer CDN where anyone can serve bytes, every chunk is BLAKE3-verified and clients pay per megabyte in USDC, targeting about $0.01/GB; currently on testnet.
Deedglass
Safety layer for AI agents that change databases and health records: rules decide each agent tool call, a check compares what the system really changed with what the agent reported, and each action is sealed as a signed record anyone can verify offline, with a person able to undo it. npx deedglass opens a local app in your browser with no account; works with Claude Code, Cursor, Claude Desktop, VS Code and Postgres. Apache-2.0 core, ee/ under FSL-1.1-ALv2.
Docling
Open-source (MIT) document parsing library started at IBM Research: converts PDF, DOCX, PPTX, XLSX, HTML and images to Markdown, HTML or JSON with layout, reading order, tables, formulas and OCR for scans. Runs locally, with docling-serve for an HTTP API and an MCP server.
Durable Actors
Open-source (MIT) alternative to Cloudflare Durable Objects from Terse: stateful serverless actors with their own SQLite database and serialized execution, for chat, collaboration and multi-agent apps, with TypeScript and Python SDKs.
E2B
Open-source (Apache-2.0) cloud sandboxes for AI agents: each sandbox is a Firecracker microVM that resumes from a snapshot, driven from the Python or JavaScript SDK, with a Code Interpreter SDK for running model-written code. The runtime can be self-hosted on your own hardware. Hobby is free with a one-time $100 credit; Pro is $150 a month plus per-second usage.
e2e by TesterArmy
Open-source (Apache-2.0) end-to-end testing framework for web, iOS and Android: describe a goal in plain language, an agent drives the app, and assertions verify the result; recorded steps replay with no model calls. From YC-backed TesterArmy.
ego lite
Free browser for AI agents on macOS, with Windows in beta: Claude Code, Codex or Cursor drive it through the open-source (MIT) ego-browser skill in their own isolated Spaces while you keep browsing, inheriting your Chrome logins and cookies; Linux is on the roadmap.
Egres
Open-source (Apache-2.0) Postgres-compatible database written in Zig by Dgraph founder Manish Jain for heavy, multi-tenant workloads: speaks the Postgres protocol so psql, drivers and ORMs connect unchanged, runs on local disk or S3, compresses storage, needs no VACUUM, branches databases and tables instantly and meters resources per query. First release is single node with basic queries (equality-only, no joins).
Enzyme
Open-source (Apache-2.0) Rust tool that builds a local index of your Markdown notes from their folders, tags, links and dates, so Claude Code, Codex or another terminal agent can pull up related notes and cite them.
esp32sim
Open-source (MIT) ESP32 emulator written in Rust that runs real firmware locally or in the browser, with no hardware or cloud needed.
Farol
Free open-source macOS terminal for running Claude Code and Codex in parallel with status sidebar and git worktrees.
farol (PR risk map)
Free, open-source (MIT) CLI and GitHub Action from Winnin that runs after your AI code review and tells the approver how risky a pull request is: a 0-100 risk score and verdict from reach, diff coverage, security findings, contract breaks and dependency changes, plus the pages, APIs and jobs the change reaches. Static analysis only, for TypeScript/React, Go and Python; never blocks a merge.
Firecrawl
Web data API for AI agents: scrape any URL into clean Markdown or JSON, crawl and map whole sites, search the web, run browser sessions and monitor pages, with an MCP server. Document parsing too: PDFs, including scans with OCR, and Word, Excel and PowerPoint files to Markdown at 1 credit a PDF page. Open source under AGPL-3.0 with a self-host guide, or use the cloud with 1,000 free credits a month.
ForgeMesh Pay-per-Crawl
Open-source (GPLv2) WordPress plugin that answers AI crawlers, SEO crawlers and scripts with HTTP 402 and serves the page once they pay your per-page price in USDC on Base via x402, straight to your wallet. Humans and reverse-DNS-verified search engines read free; bot analytics and a Monitor mode in wp-admin.
Frink
Open-source (MIT) desktop app for macOS and Linux to run parallel coding agents and multi-step Flows triggered by schedules, webhooks or events from Linear, Sentry, PostHog, Vercel and more, with approval steps and a Work Queue; runs locally with the AI coding tool you already use, no account.
Gauge CLI
Open-source (MIT) CLI that runs real coding agents against your Skills, CLIs, SDKs, MCP servers and docs, captures where they get stuck and lets your own agent test fixes locally in Docker; part of the Gauge agent-led growth platform.
GenesisDB
Event sourcing database, open source under MIT since version 2.0 (Oct 24, 2026) with no editions, license keys or event limits: one static Go binary storing CloudEvents 1.0 records in a subject tree, with precondition-guarded batch commits, the GDBQL query language, live subscriptions over Server-Sent Events, a SHA-256 hash chain you can audit in one request, GDPR erasure, backups, Prometheus/OpenTelemetry metrics and an embeddable Go mode. Runs from one Docker command; SDKs and a VS Code extension.
GhostBase
Open-source (MIT) keyboard-driven terminal database studio for SQLite, PostgreSQL and MySQL, from the maker of Ghostman: it connects from DATABASE_URL in your .env, double-confirms or (in one-key read-only Safe Mode) blocks DELETE or UPDATE without WHERE, DROP and TRUNCATE, runs EXPLAIN with one key, beautifies SQL, and exports results as INSERT statements or Markdown tables. Built on Textual; pip install ghostbase-cli (Python 3.10+).
Ghostman
Open-source (MIT) keyboard-driven terminal API client and webhook inspector built on Textual: compose GET, POST, PUT, PATCH and DELETE requests, see DNS and TTFB latency and formatted JSON, and catch incoming webhooks on a built-in local listener (port 9090) without ngrok. Local-first, no account; collections are plain JSON/YAML files you can commit to Git. Install with pip install ghostman (Python 3.10+).
Glider
Open-source single-node vector database in Rust that makes every acknowledged write durable in S3-compatible storage, with filtered nearest-neighbor search over an HTTP API, a Python client and an MCP memory server for agents.
Google ADK
Google's open-source (Apache-2.0) Agent Development Kit: code-first agents and graph workflows, multi-agent hierarchies, MCP and OpenAPI tools, tool confirmation, a local dev UI and built-in evals. Optimized for Gemini but model-agnostic. Python, Java, Go, TypeScript and Kotlin; deploy with Docker, Cloud Run or Vertex AI Agent Engine.
Google Gemini CLI
Google's open-source (Apache-2.0) coding agent for the terminal: it reads and edits your codebase, runs shell commands, connects MCP servers and runs headless with gemini -p for scripts. Now built for Gemini Code Assist Standard and Enterprise teams and paid Gemini API or Vertex AI keys; free and Google AI Pro/Ultra users moved to Antigravity CLI.
Guardrails AI
Open-source (Apache-2.0) Python framework for LLM guardrails: wrap model calls in Guards that run validators on input and output, from PII and toxicity checks to your own rules, and get structured data back. Validators come from Guardrails Hub as pip packages, and it runs in your code or as a REST server with guardrails start.
guilds.run
Open-source (AGPL-3.0) multi-agent teams you can inspect: debug every prompt, tool call, memory change and agent interaction, control permissions and pick the model per agent. Self-host free on your own machine with Docker Compose; hosted plan from $19/month coming soon.
Halv
Desktop workspace that runs Claude Code, Codex, Kimi and GLM side by side on the plans you already pay for, with up to 32 live panes, a local code index and context compression to cut token spend. The app is open source (Apache 2.0) on macOS, Windows and Linux; optional Halv Cloud routing is $10/month.
Handshake
Native macOS workspace for coordinating coding agents, formerly Twine: controlled workflows, visual traces and cross-agent memory, with roles filled by Codex, Claude Code, OpenCode, pi, Antigravity, OMP or Kiro CLI. Apple Silicon, macOS 26+, MIT-licensed.
Hatamoto
Open-source (Apache-2.0) batteries-included CMS that runs as one Go binary next to Postgres 16: visual page builder, SEO panel, page cache, forms, redirects, JSON-LD, sitemaps and llms.txt in core, server-side AI crawler analytics that flag spoofed bots, an MCP server with scoped keys, sandboxed WebAssembly plugins and a WordPress importer that audits every old URL. No telemetry, no paid edition.
Hazzel
Small, readable open-source (Apache-2.0) terminal coding agent in Python: bring your own key for one of eight providers or run Ollama locally, no subscription, every change shown as a diff before it touches disk, with undo, /review, /commit and per-turn token cost.
Helicone
Open-source (Apache-2.0) AI gateway and LLM observability platform: point an OpenAI-compatible client at one URL to reach 100+ models with routing and automatic fallbacks, and every request is logged with cost, latency, sessions and agent traces. Prompt versioning, a playground, and scores and datasets for evaluating outputs. Self-host with Docker Compose or use the cloud, free for 10,000 requests a month.
Hob
Free, open-source (MIT) desktop app from Frigade for Mac, Windows and Linux that works on your files like the Claude and ChatGPT apps, but runs open-weight models (Gemma 4, gpt-oss) on your own computer via llama.cpp: picks a model for your hardware, writes sandboxed Python for ad hoc tools, reads images and PDFs, adds MCP connectors and works fully offline.
k10s
Open-source (Apache-2.0) Kubernetes terminal UI you can click: searchable, themeable, a single static binary for macOS, Linux and Windows, with an AI assistant that knows your cluster, namespace and selected object.
Kavach
Open-source (Apache-2.0) flight recorder for journal-driven services: records every input, clock read and random read, and when a step panics or breaks an invariant writes a .kavach fixture that replays the crash byte for byte with no broker, database or network, then rejects narrow fixes that fail across perturbed variants. SDKs in 12 languages plus agent skills; pre-alpha.
KiviDB
Open-source (AGPL-3.0), multi-threaded Redis and Valkey alternative written in Rust that speaks RESP2/RESP3, so existing Redis clients work unchanged, with full-text and vector search built in; self-host it or use KiviDB Cloud.
kube32
Open-source (Apache-2.0) Kubernetes-compatible control plane and WebAssembly pod runtime for ESP32-S3 microcontrollers: manage a cluster of boards with kubectl or k9s over Wi-Fi or USB serial, with pods written in Rust, C or AssemblyScript and a host simulator to try it without hardware.
Laminar
Open-source (Apache-2.0) observability for AI agents, written in Rust: one-line OpenTelemetry tracing for the Vercel AI SDK, Browser Use, Stagehand, LangChain, OpenAI, Anthropic and more, Signals that flag behaviour you describe in plain English, evals from an SDK and CLI, browser session recordings, SQL over traces and MCP access for coding agents. Self-host with Docker Compose, or use the cloud, free for 1 GB of data.
Langfuse
Open-source LLM engineering platform: traces and sessions for LLM apps and agents with token and cost tracking, prompt management, datasets, LLM-as-judge and human evals; OpenTelemetry-based, self-host free or use Langfuse Cloud in the US, EU or Japan.
LangGraph
LangChain's low-level orchestration framework for long-running, stateful agents: durable execution that resumes where a run failed, human-in-the-loop checks on agent state, and short- and long-term memory. Python 3.10+ or LangGraph.js, with or without LangChain. Open source (MIT); deploy it yourself or on LangSmith Deployment.
Lasm
Open-source (MIT) compiler that turns ordinary Lean 4 programs into WebAssembly so one formally verifiable code base can ship as a Node server, AWS Lambda, Vercel, Netlify or Azure function, edge or WASI module, or a browser app, with Lean frameworks for HTTP, UI, typed RPC, DOM and KV plus JS/npm interop. Ships on npm with Lean bundled (npm create @lasm@latest); its RealWorld example carries 117 proved theorems. Early (0.3.x).
Letta
Stateful agents with memory that persists and improves with experience, from the makers of MemGPT: Letta Code ships a terminal UI, an app server for self-hosted agents and an Agent SDK, with Letta Cloud to carry memory across machines. Open source (Apache-2.0); free with your own API keys, Pro $20/month.
Lights-on Software Factory
Open-source (MIT) boilerplate for running Claude Code as a software factory: a sandboxed container, a deterministic bash-command regulator, lint hooks for custom rules and a multi-agent workflow generator.
LiteDeck
Agentless desktop GUI for managing servers over plain SSH: files, editor, services, processes, containers, network, sessions, monitoring and a terminal in one window, with nothing installed on the server; macOS, Windows and Linux, Apache-2.0.
LiveKit Agents
Open-source (Apache-2.0) framework for realtime voice and video agents in Python or Node.js: mix any STT, LLM, TTS or realtime model, semantic turn detection, MCP tools, a built-in test framework and phone calls through LiveKit's SIP stack. Self-host the whole stack with the open-source LiveKit server, or deploy to LiveKit Cloud, free for 1,000 agent minutes a month.
llmspeed
Open-source simulator that lets you feel a local LLM's tokens/sec and time-to-first-token on a chosen GPU or Mac before you buy the hardware, based on community benchmarks.
Luke
Open-source (Apache-2.0) Mac app for planning a feature out loud: Luke reads your code while you talk and writes a plan you can paste into Claude Code or Codex.
Lumabri
Open-source (Apache-2.0) tool written in C that runs a private inference service across your own computers on a LAN, splitting a model's layers between machines so models too big for one computer can run; powered by the Colibri engine.
Maclet
Open-source (Apache-2.0) container runtime for Apple Silicon Macs, written from scratch in Rust and Swift: instead of wrapping Docker Engine or containerd it boots a Linux VM through Apple's Virtualization Framework and implements namespaces, cgroups v2 limits, OverlayFS, bridge networking and OCI image pulls itself, with run, exec, logs, ps and stats commands. Early-stage project.
Mastra
TypeScript framework for AI agents and apps: agents with tools, graph-based workflows that suspend for human approval and resume, model routing across 40+ providers, built-in evals and observability, and Mastra Studio to test agents locally. Apache-2.0 outside its ee/ enterprise directories; Mastra Platform free to start, Teams $250/month.
MELRA
Open-source local MCP runtime that checks AI-agent tool calls against policy, gates risky actions on approval, verifies results and parks uncertain outcomes instead of blindly retrying after timeouts. Alpha; AGPL-3.0, SDKs Apache-2.0.
Mem0
Memory layer for AI agents and apps: send it conversations and it extracts, updates and retrieves the memories that matter for each user, through Python and Node SDKs, an API, MCP and a CLI. Open source (Apache-2.0) as a library or self-hosted server, or the hosted platform with a free plan.
Noctty
Open-source (MIT) native Windows terminal built on Ghostty's terminal core, formerly winghostty: tabs, splits, command palette, session restore and a shell picker for PowerShell, cmd, Git Bash and WSL. Tabs show when a coding agent is working, blocked on you, done or failed (OSC 7501), and most Ghostty config and themes work. No telemetry; Windows 10 1809+ and 11 on x64 and ARM64, winget install AmanThanvi.noctty.
NVIDIA NeMo Guardrails
NVIDIA's open-source (Apache-2.0) toolkit for programmable guardrails on LLM apps: input, output, dialog and retrieval rails that keep a bot on topic, detect jailbreaks and prompt injection, fact-check and moderate output. Configured in YAML and Colang, Python 3.10 to 3.13, works with LangChain.
office-engine
Open-source (MIT) TypeScript library to view and edit DOCX, XLSX and PPTX files in the browser and save back to the original format. Loads progressively with HTTP Range requests and a Web Worker parser, virtualizes pages, cells and slides, supports 134 spreadsheet formula functions and real-time collaboration. One-line React DocViewer component, a vanilla mount() or an <office-viewer> web component; npm @p10node/office-engine.
Omnara
Open-source managed agent platform, pitched as a self-hostable alternative to Claude Managed Agents and OpenAI's Agents API: run AI agents on any model and any machine through an API and CLI, with tools, secrets, permissions and streaming built in. Self-host free under Apache-2.0 or use Omnara Cloud.
OmniDiff
Open-source (AGPL-3.0) content-aware diff tool written in Rust, used as a terminal viewer or as git's external difftool: it highlights the parts of a line that changed and shows moved code as moved instead of marking whole lines deleted and inserted, across 25 languages, and also diffs config, images, PDFs, archives, fonts and cursors. Prebuilt binaries for Linux, macOS and Windows, Homebrew, apt and Nix, plus VS Code and Neovim plugins. Early (v0.3.0).
OmniPTY
Open-source (MIT), GPU-rendered Rust terminal for macOS and Linux with built-in splits, pinnable workspaces, a vim-style file tree, copy mode and a git-aware status bar; no account or telemetry.
OneDeploy
Deploys open-source apps (WordPress, Gitea, Grafana, Dify and dozens more) on a dedicated server with TLS and nightly backups, billed hourly with a monthly cap.
OpenAI Agents SDK
OpenAI's open-source (MIT) SDK for multi-agent workflows in Python or TypeScript: agents with tools, handoffs, guardrails, sessions and human-in-the-loop, built-in tracing, sandbox agents for long tasks, and voice agents. Works with the OpenAI APIs and 100+ other LLMs. Free; you pay for model usage.
OpenAI Codex CLI
OpenAI's open-source (Apache-2.0) coding agent that runs locally in your terminal: it reads your repo, edits files and runs commands, with codex exec for scripts and CI. Sign in with ChatGPT or use an API key.
OpenCode
Open-source AI coding agent for terminal, desktop and web, with multi-session agents and 75+ model providers.
Opengeni
Open-source cloud agent harness: every agent gets its own computer plugged into your repos and tools, runs for hours after you close the laptop, and the team shares the work; EU-hosted, any model, Pro from $20/month.
Opik
Comet's open-source (Apache-2.0) LLM observability and evaluation platform: traces for agents and multi-turn conversations, datasets and experiments with 30+ LLM-as-a-judge and heuristic metrics, pass/fail test suites, a PyTest integration for CI, online evaluation rules on production traces, guardrails and an agent optimizer. The full platform, backend included, self-hosts free; Opik Cloud is free for 25K spans a month.
Pando
Open-source, self-hosted platform for running internal apps, including AI-built ones: point it at a git repo or image and it builds the app, scans it for vulnerabilities, runs it on an isolated network and puts it behind your SSO. Alpha, needs Docker; AGPL-3.0.
Parley
Open-source (Apache-2.0) single Go binary that puts your Claude Code, Codex and OpenCode sessions on one local IRC channel with you, so they tell each other when something changes and ask when they need input; you read every line in any IRC client, only your nick carries authority, and a breaker stops runaway loops until you write.
Parseable
Open-core (AGPL-3.0) observability platform written in Rust: logs, metrics and traces in one binary on S3-compatible object storage, with SQL and PromQL, OpenTelemetry-native ingest, self-hosted or as Parseable Cloud.
Petal
Free, open-source pair programming app from the makers of CoScreen: low-latency, high-resolution window sharing with remote control, for Mac and Windows.
phpClaw
Open-source (MIT) AI agent framework for PHP 8.1+: a ReAct loop with tools (allowlisted shell, HTTP with SSRF checks, sandboxed file access, database queries, code search), memory and guard chains that screen messages before the model sees them. Works with Anthropic, OpenAI, Groq, Gemini, Mistral, DeepSeek or Ollama; eight adapters for Laravel, Symfony, Drupal, Magento, WordPress/WooCommerce, Joomla, PrestaShop and OpenCart, and an MCP server package that exposes your tools to Claude Code or Cursor.
pi-cowboy
Open-source (MIT) multi-agent orchestrator for the Pi coding agent that runs Pi, Claude Code, Codex or OpenCode as parallel subagents in isolated copy-on-write Git worktrees inside Herdr panes.
Pipecat
Open-source (BSD-2-Clause) Python framework for realtime voice and multimodal agents, maintained by Daily: composable pipelines over WebRTC or WebSockets, 80+ LLM, STT and TTS services, Pipecat Flows for structured conversations, multi-agent handoffs and client SDKs from JavaScript to ESP32. Run it anywhere, or on Pipecat Cloud from $0.01 an active minute.
Plausible
Lightweight, privacy-friendly, open-source web analytics.
Playwright MCP
Microsoft's MCP server that lets Claude Code, Codex, Cursor, VS Code and other MCP clients drive a browser through Playwright's accessibility snapshots instead of screenshots: Chrome, Firefox, WebKit or Edge, headed or headless, or attached to your logged-in browser through an extension. Open source (Apache-2.0) and free.
PostHog
Open-source product analytics suite with session replay, feature flags and experiments.
proc
Open-source (MIT) Rust CLI for macOS, Linux and Windows that finds and manages processes by port, PID, name or path: see what is on :3000 and why, then stop or free it, with confirmations and --dry-run. Ships an agent skill so Claude Code, Codex, Cursor and Gemini CLI know when to use it.
Pug
Open-source (AGPL-3.0) product analytics with unified user profiles: autocapture, trends, funnels, retention and user flows; self-host it or start free on EU-hosted, cookieless Pug Cloud.
pw-repl
Open-source (MIT) Playwright REPL that drives Chromium over CDP, in your own browser with its logins or a headless one, shared by you and your AI agents: agents send commands with pw-repl send, every command shows in the REPL, and watch records your manual steps for the agent to read.
Pydantic AI
Typed Python agent framework from the Pydantic team: any model a string swap away with fallback, validated structured outputs, MCP, evals and durable execution on Temporal, DBOS, Prefect and more. One agent runs as a CLI, a web chat or a realtime voice agent. Open source (MIT) and free; Logfire tracing is optional.
Qdrant
Open-source (Apache-2.0) vector database and search engine written in Rust: filtered vector search you can self-host, or run on Qdrant Cloud on AWS, GCP or Azure with a free 1 GB cluster, usage-based dedicated clusters, and hybrid or private cloud on your own infrastructure.
RDST
Readyset's open-source desktop agent that watches PostgreSQL or MySQL read-only, flags slow or regressed queries and proposes index, setting or rewrite fixes.
rostr
Open-source (MIT) CLI, hooks and skill that give every Claude Code or Codex session a unique name and emoji drafted from a roster you pick, so notifications and messages are traceable and agents can refer to each other; rostr stats shows who is working on what. Works with tmux and herdr; local by default, optional end-to-end encrypted cloud roster.
Rustable
Open-source (MIT) desktop database client written in Rust with a GPU-rendered egui UI, for PostgreSQL, SQLite, MySQL, MariaDB and standalone Redis: multiple connections in separate windows, SQL tabs, saved queries, schema browsing, import and export, row edits you review before saving, and SSH tunnels on macOS and Linux. Builds for macOS (Apple Silicon), Windows and Linux x64; early software, with an in-browser WASM demo.
siltop
Rust terminal system monitor for Apple Silicon Macs showing CPU, GPU, power, clocks, temperatures and processes, without sudo or telemetry.
skill-spotter
Open-source (MIT) Claude Code plugin that notices tasks and instructions you keep repeating and offers to save them as a /skill or a CLAUDE.md rule; data stays in a local SQLite file, no telemetry, and it never creates a skill without you.
slotwatch
Open-source (MIT) terminal UI that watches PostgreSQL replication slots: how much WAL each slot holds, how fast that grows, who reads it and how long it has sat idle, worst first, with a note on why a slot was flagged. Read-only, so it never drops or changes anything. slotwatch --check gives an exit code (and optional JSON) for cron, CI or Kubernetes. Tested on Postgres 14 to 18; Homebrew, go install, Docker or release binaries.
Sphinx
Free, MIT-licensed Git hook that quizzes you on what your coding agent's diff actually does before a push to protected branches goes through; works with Claude Code, Codex, Cursor or plain Git.
spinf-serve
Open-source (Apache-2.0) inference server for bulk classification and decisions on one GPU: it reads each piece of content once and scores many questions about it in the same pass, returning a probability over the options you give instead of generated text. OpenAI-compatible API, same as the hosted spinf service; needs Linux and a 24 GB NVIDIA GPU.
Spotnote
Open-source (MIT) Vite plugin: click any element in your running app, type what should change, and get a prompt with the exact source file, line and column to paste into Claude Code, Cursor or Codex; local-only and dev-mode only.
Stackdome
Open-source, self-hostable alternative to Railway, Render and Heroku on Kubernetes: deploy from GitHub or an image, wire services on a visual canvas, managed Postgres with backups and PITR, per-branch preview environments and whole-stack rollbacks. Drive it from a coding agent skill, the canvas or a CLI; MIT licensed.
Steel
Open-source (Apache-2.0) browser API for AI agents: Steel Browser runs Chrome sessions you drive with Puppeteer, Playwright or Selenium, keeps cookies and storage across requests, rotates proxies and turns pages into Markdown, screenshots or PDFs. Self-host it with Docker or use Steel Cloud, free to start with $30 of credits.
Sumi.css
Minimalist, classless-first CSS framework: one file (6.7 KB min+gzip), no build step or JavaScript, automatic light/dark mode, theming via CSS custom properties and zero-specificity element styles that are easy to override. MIT-licensed.
Supabase
Open-source Postgres development platform with auth, storage, realtime and edge functions.
Supermemory
Memory and context engine for AI agents: learns from each user's chats, files and URLs, stores it in a vector-graph database and injects what matters into your agent's context, through an API, MCP and plugins for Claude Code, Cursor and more. Open source (MIT); hosted free plan with $5 of credits a month, Pro $19/month.
sweet-search
Open-source (Apache-2.0) local code search for AI coding agents: index a repo once and the index updates itself as you edit, uncommitted changes included, then Claude Code, Codex or opencode get six tools (search, grep, find, semantic, trace, read) in place of grep-and-read. Models run on your machine with no API keys or cloud; the author reports 5-33% cheaper agent runs across 200 tasks. macOS and Linux, Node.js 22+; npm install -g sweet-search.
TablePro
Free, open-source (AGPL-3.0) native database client written in Swift, pitched as an open TablePlus: connects to 30+ SQL and NoSQL databases through native drivers, with built-in AI chat, inline suggestions and an MCP server for Cursor, Raycast or Claude Desktop (bring your own key or run Ollama). macOS and iOS/iPad; extras like iCloud Sync are paid, Linux version in development.
Tenbri
Open-source Agent Decision Record: a signed, append-only, hash-chained record of every decision an AI agent makes, verifiable offline; one line instruments Claude, OpenAI and LangGraph agents, with Python and TypeScript SDKs and plain files on storage you control. Apache-2.0, written in Rust.
Tinycap
Open-source (MIT) native macOS menu-bar screen recorder and screenshot tool for PR-sized clips: record a window, screen or dragged area, trim, and export MP4 (H.264 or HEVC), WebM or GIF with a 'fit under N MB' option, or mark up screenshots with arrows, text, pixelation and crop. Everything stays local. Requires macOS 15; install from the DMG or Homebrew.
uji
Small, lightweight terminal coding agent where everything is a module you can swap at runtime, even the core: every view is Lua you can rewrite, and you add plugins as you go. Install with a curl script or Homebrew; GPL-3.0.
Ulak
Open-source (MIT or Apache-2.0) Rust CLI that runs a local Compose project's Docker workloads on a server you control over SSH, with no local Docker daemon: keeps your editor and checkout local, syncs the files Docker needs, runs Docker commands remotely and forwards published ports back to localhost. Installs nothing on the server; macOS and Linux.
Unsloth
Open-source fine-tuning library and desktop app for your own GPU or a free Colab notebook: LoRA, QLoRA, full fine-tuning, GRPO, DPO and FP8 for LLMs, vision, TTS and embedding models, which Unsloth says train 2x faster with 70% less VRAM. Exports to GGUF. Core Apache-2.0, Studio UI AGPL-3.0; Windows, Linux and macOS.
Unstructured
Document parsing for RAG: partition 50+ file types with Fast, High-Res or VLM strategies, then chunk, enrich and embed, with 40+ source and destination connectors. Hosted at $0.015 a page after 10,000 free pages, or the open-source library under Apache 2.0.
Weatherdeck
Open-source, read-only status board for TV or phone showing what your AI coding agent lanes and machines are doing and what is waiting on you.
Weaviate
Open-source (BSD-3-Clause) vector database that stores objects and vectors together, with hybrid search, filtering, multi-tenancy and vector compression. Self-host it or use Weaviate Cloud, which adds hosted embeddings and a Query Agent; free cluster for 100,000 objects.
Weir
Open-source (Apache-2.0) API key leak detection for AI agents: plants fake keys where real ones live, runs your agent's flows and reports whether they reached traces, logs, console output, the model or other services (leak, clean or incomplete), and in Claude Code shows which of your real keys entered or left a session, with an optional hook that redacts them. pip install weir-scan.
WhatsApp MCP
Open-source (MIT), read-only MCP server you deploy to your own Cloudflare account so Claude Code or any MCP client can search and read your WhatsApp chats; it can't send messages and is unofficial (uses the WhatsApp Web protocol).
withHuman
Open-source human approval layer that intercepts AI agent tool calls, applies rules, and routes risky actions to reviewers.
XTrace
Open-source macOS app (Apple Silicon) that reads your local Claude Code, Codex and Cursor history to show agent activity, estimated human time, API-equivalent spend and how fast you are using your Claude and Codex limits. Apache-2.0.