Anthropic
Open source activity
As of Oct 28, 2026
Anthropic's most recently active public repositories right now are almost entirely about the Claude Code and Cowork ecosystem rather than model research: the official and community plugin marketplaces, the public Agent Skills repository, and a Python SDK for building Claude agents were all touched the same day. That's a visible shift in where the company's open-source energy is going — toward developer tooling and a third-party extension ecosystem, not toward publishing new model architectures or training code.
Two smaller, more specific repos round out the recent activity: an "oss-scanner" security tool and a vertical-specific "financial-services" repository, suggesting Anthropic is also investing in industry reference implementations and open-source dependency-security tooling alongside the general-purpose SDKs and quickstarts. None of this touches Claude's weights or training pipeline directly — as with most frontier labs, the model itself stays closed, and what's public is the surrounding developer surface.
Most active repositories
| Repository | Description | Language | Stars | Last pushed |
|---|---|---|---|---|
| anthropics/claude-quickstarts | A collection of projects designed to help developers quickly get started with building deployable applications using the Claude API | TypeScript | 19,045 | Oct 29, 2026 |
| anthropics/claude-cookbooks | A collection of notebooks/recipes showcasing some fun and effective ways of using Claude. | Jupyter Notebook | 53,909 | Oct 29, 2026 |
| anthropics/oss-scanner | — | Dockerfile | 1,632 | Oct 29, 2026 |
| anthropics/claude-plugins-community | Community plugin marketplace for Claude Cowork and Claude Code. Read-only mirror — submit plugins at clau.de/plugin-directory-submission. | JavaScript | 4,790 | Oct 29, 2026 |
| anthropics/claude-plugins-official | Official, Anthropic-managed directory of high quality Claude Code Plugins. | Python | 45,214 | Oct 29, 2026 |
| anthropics/knowledge-work-plugins | Open source repository of plugins primarily intended for knowledge workers to use in Claude Cowork | Python | 33,762 | Oct 29, 2026 |
| anthropics/claude-agent-sdk-python | — | Python | 8,384 | Oct 29, 2026 |
| anthropics/skills | Public repository for Agent Skills | Python | 184,653 | Oct 28, 2026 |
| anthropics/financial-services | — | Python | 40,902 | Oct 28, 2026 |
| anthropics/life-sciences | Repo for the Claude Code Marketplace to use with the Claude for Life Sciences Launch. This will continue to host the marketplace.json long-term, but not the actual MCP servers. | Python | 633 | Oct 28, 2026 |
| anthropics/claude-for-financial-advisors | Claude for Financial Advisors: a Claude Cowork plugin with ready-to-run workflows for financial advisors, drawing on third-party connectors. | HTML | 126 | Oct 28, 2026 |
| anthropics/claude-code | Claude Code is an agentic coding tool that lives in your terminal, understands your codebase, and helps you code faster by executing routine tasks, explaining complex code, and handling git workflows - all through natural language commands. | TypeScript | 153,816 | Oct 27, 2026 |
| anthropics/claude-code-action | — | TypeScript | 9,702 | Oct 27, 2026 |
| anthropics/claude-code-base-action | This repo is a mirror of the contents of base-action in https://github.com/anthropics/claude-code-action. | TypeScript | 1,022 | Oct 27, 2026 |
| anthropics/claude-agent-sdk-typescript | — | Shell | 1,846 | Oct 27, 2026 |
| anthropics/homebrew-tap | Homebrew formulae for Anthropic tools. | Ruby | 35 | Oct 27, 2026 |
| anthropics/anthropic-cli | The CLI for the Claude API | Go | 702 | Oct 27, 2026 |
| anthropics/sandbox-runtime | A lightweight sandboxing tool for enforcing filesystem and network restrictions on arbitrary processes at the OS level, without requiring a container. | TypeScript | 6,843 | Oct 27, 2026 |
| anthropics/anthropic-sdk-go | Access to Anthropic's safety-first language model APIs via Go | Go | 1,235 | Oct 27, 2026 |
| anthropics/formal-math | — | Lean | 424 | Oct 27, 2026 |