What you’ll need
- A Circuit account (for uploading agents and hosted dev runs)
- Python 3.14 with uv for Python agents
Install the CLI
Install the Circuit CLI with the dev installer:circuit new does not require login. Sign in later when you use account-backed commands such as upload or hosted dev runs.
You can also install directly with Bun:
Continue from Agent Builder
The Agent Builder’s Continue locally command installs the CLI if needed, signs you in, downloads the chat workspace, and installs project dependencies:./<agent-name>/. The command contains no credential; it uses the normal circuit auth login browser/passkey flow.
The SDK comes with the CLI
There is nothing else to install. The Circuit SDK is provided by the environment your agent runs in - the CLI locally, the hosted runtime when deployed - and is never a dependency of your project:- TypeScript agents import from
circuit:sdk(the same pattern asnode:fsorcloudflare:workers). The CLI keeps a committedcircuit-sdk.d.tsat your project root up to date so your editor andtscresolve it - the same shape Wrangler shipsworker-configuration.d.ts. - Python agents import from
circuit_sdk. The CLI installs the module into your project’s.venv.
circuit check - it repairs the SDK installation as part of validating the project.