Cadenya is an API-first agent runtime. It runs the agent loop for your app as a hosted service. Your agents call tools from an OpenAPI document, an MCP server or your own HTTP endpoints. A person approves the calls that need it, and every step streams to your app or to an embeddable chat widget.

1. Create a free account at https://app.cadenya.com/signup. The Free plan needs no card.

2. Copy your API key from https://app.cadenya.com/account/apiKeys and set it as CADENYA_API_KEY.

3. Install the CLI, sign in and pick a workspace:

   brew install cadenya/tools/cadenya   # Windows: choco install cadenya
   cadenya auth login                   # approve the one-time code in your browser
   cadenya workspaces list              # set one as CADENYA_WORKSPACE_ID

4. Describe your agent, its tool sets and its variations as YAML files in .cadenya/ next to a cadenya.yaml, then run cadenya config apply.

The docs are at https://cadenya.com/docs. To give your coding agent Cadenya's skills, run npx skills add https://cadenya.com/docs.

• cadenya-cli is the cadenya CLI. It signs you in with cadenya auth login, runs the API from your terminal, and applies your .cadenya/ files with cadenya config apply.
• cadenya-config-loader is a GitHub Action that validates, plans and applies the same files in CI.
• cadenya-openapi points to the OpenAPI spec, which is live at https://openapi.cadenya.com/api-spec.yml.

• widgets-sdk is the TypeScript client for Cadenya Widgets, which put a Cadenya agent in your web app (npm install @cadenya/widgets).
• widgets-ui-react is the React UI kit for it, with conversations, streaming replies and tool approvals (npm install @cadenya/widgets-ui-react).

• examples-slacktacular is a Slack app that runs Cadenya agents and shows tool approvals in the thread.
• cadenyaception-widgets-sandbox holds three widget demos: a travel concierge, chess and a diagram builder. Try them at https://widgets-demo.cadenya.com.

• redwood generates the SDKs from the OpenAPI spec.
• mcp-grpc-gateway exposes gRPC services as MCP tools.
• prorate adds rate limits to gRPC services from proto annotations.
• protoc-gen-go-dbtypes generates Go types that store protobuf messages in a database.

• Docs and the API reference
• Pricing for the Free, Growth and Enterprise plans
• Handwritten, Robert Ross's posts on how Cadenya is built
• Articles on agent frameworks, durable execution and approvals