> For the complete documentation index, see [llms.txt](https://gopersonal.gitbook.io/calvin/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://gopersonal.gitbook.io/calvin/user-guides/blocks-marketplace.md).

# Blocks Marketplace

The Blocks Marketplace lets you extend your workspace with infrastructure services and knowledge packs. You can access it by clicking the Blocks button in the workspace toolbar, or by selecting "Add Block" from the "+" menu in the chat input.

The marketplace is organized into two categories: Building Blocks and Skills.

Building Blocks are infrastructure components that add real services to your workspace. Each block runs as part of your workspace environment and may require environment variables to configure. The available building blocks include ai-sdk, which provides access to AI model providers like Vercel AI SDK and LLM integrations and requires three environment variables; database, which provisions a PostgreSQL/SQL database for your application and requires one environment variable; error-tracking, which integrates Sentry for monitoring and error tracking and requires one environment variable; generative-image, which adds AI image generation capabilities powered by Gemini and requires one environment variable; google-search, which enables programmatic Google Search access via API and requires one environment variable; image, which provides image processing capabilities including background removal via Photoroom and requires one environment variable; object-storage, which adds cloud object storage for files and assets; and trigger, which enables automation triggers for event-driven workflows.

When you install a building block, Calvin adds the necessary dependencies and configuration to your project. The agent can then use these services when executing tasks — for example, if you have the database block installed and ask Calvin to add a product listing feature, it can create the database schema, write the queries, and wire up the API automatically.

Skills are community-contributed knowledge packs that enhance how agents work with specific technologies. Unlike building blocks, skills do not add infrastructure — they add expertise. Skills teach the agent best practices, patterns, and conventions for a particular technology or framework.

You can search for skills by technology name. For example, searching for "react" reveals skills like vercel-react-best-practices (with over 117K installs), react:components, react-native-best-practices, react-state-management, react-email, and react-modernization, among others. Each skill shows its install count, helping you gauge community adoption.

Skills are particularly valuable because they keep your agents up to date with the latest conventions and patterns for your stack. Installing a Next.js skill, for example, ensures the agent follows current best practices for routing, data fetching, and server components when building your application.

You can also add blocks directly from within a chat by clicking the "+" button next to the chat input and selecting "Add Block." This is convenient when you are mid-task and realize you need a new capability.


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