Deploying

Curb runs anywhere Node runs. You have two ways to put an agent live:

Hosting on KugelAudio is in closed alpha and switched on per organization. Phone numbers, GitHub deploys and how a hosted agent runs are in the KugelAudio docs.

Four commands take a local project to a live agent on KugelAudio:

npm create curb.js my-agent
cd my-agent && npx curb login
npx curb secrets push
npx curb deploy

deploy ends by printing the agent’s playground URL, where you can call it from the browser.

curb login

Opens the KugelAudio sign-in page in your browser and waits up to five minutes for you to confirm. The terminal prints the URL too, so on a machine without a browser you can open it anywhere that can reach 127.0.0.1 on this machine.

The session is stored in ~/.config/curb/credentials.json (or $XDG_CONFIG_HOME/curb/), readable only by you (mode 0600), and refreshed automatically when it expires. npx curb logout revokes it and deletes the file.

Run in a Curb project, the sign-in page also asks which organization and project to create an API key in (“Curb CLI on ”, revocable on the API keys page). The CLI keeps it beside the session in ~/.config/curb/project-keys.json (mode 0600), never in the project and never printed, and saves that project in .curb/link.json when there is no link yet, so the first curb deploy deploys there. Every Curb command in the project then runs on your login: there is no key to copy. npx curb logout deletes the stored keys too.

Prefer an API key (CI, a server)? Set KUGELAUDIO_API_KEY in .env or the environment; it wins over the login, and curb login then creates no key.

curb secrets push

Sets every variable in the project’s .env on the agent’s production environment: your provider keys such as ANTHROPIC_API_KEY or AZURE_SPEECH_KEY when the agent uses anthropic() or azure.stt(). KugelAudio provides KUGELAUDIO_API_KEY itself, so an agent on kugelaudio.llm(), .stt() and .tts() has nothing to push. Values are write-only: the command prints names, never values, and nothing can read them back. New calls use the new values; no redeploy is needed.

Skipped on purpose: KUGELAUDIO_API_KEY and KUGELAUDIO_API_BASE (the platform provides them), LIVEKIT_URL, LIVEKIT_API_KEY and LIVEKIT_API_SECRET (hosted calls get their own media grant; keep them in .env for local curb dev), and empty values.

curb deploy

Packs the project, uploads it, and makes it the agent’s live production deployment:

Packed 42 files (180.3 KiB unpacked, 51.2 KiB compressed).
Uploaded.
Revision rev_...
  build running
  build succeeded
  deployment candidate
  deployment active
Live. Try it in the playground: https://www.kugelaudio.com/dashboard/.../playground

With --json, stdout reads:

{"revisionId":"<the revision deployed>","deploymentId":"<its deployment>","state":"active","playgroundUrl":"<the playground, when known>"}

state is ready with --no-activate.

Which agent. The first deploy or secrets push in a project asks which of your agents to use, or creates a new one, and saves the choice in .curb/link.json; later runs reuse it. Without a terminal (CI, a coding agent), a first run with exactly one project and no agent creates the agent, named after the directory; any other first run needs --agent <id> and lists the ids. Delete .curb/link.json to choose again.

What is uploaded. The project directory, minus node_modules/, .git/, .curb/, .data/, .mcp-auth/, a top-level dist/, and every .env / .env.* file. The lockfile is uploaded with the source, so keep it in the project. Limits, checked before anything is uploaded:

Symlinks are kept when they point inside the project and refused when they point outside it.

In an environment a host runs for you. A host that runs your project for you (a hosted workspace) does not sign you in there. It sets CURB_PLATFORM_TOKEN_FILE to a file it keeps current with a short-lived token for one agent and one environment:

{
  "token": "<a token for that agent and environment>",
  "expiresAt": "2026-10-27T19:00:00Z",
  "platformApiUrl": "https://agents.example.com",
  "tenantId": "<organisation id>",
  "projectId": "<the agent's platform project id>",
  "environmentId": "<the environment it deploys to>",
  "kugelaudioApiKey": "<a model key that expires with the token>",
  "kugelaudioApiBase": "https://api.example.com"
}

curb deploy then deploys there with that token, reads the file on every run, and never asks which agent: .curb/link.json and --agent play no part. curb login and curb secrets push are refused with the reason; set the agent’s secrets in the dashboard.

When the file carries kugelaudioApiKey (and, optionally, kugelaudioApiBase), every Curb command runs the project on that key unless .env or the environment sets KUGELAUDIO_API_KEY: curb dev, curb test, curb say and the preview reach KugelAudio’s models with nothing to set. A running curb dev re-reads the file every 30 seconds, so it moves onto each renewed key, and curb check lists the key as coming from the workspace.

Errors you can fix

Any other refusal is printed with its HTTP status, error code and correlation id; quote the correlation id when you contact support. Set DEBUG=1 for a stack trace.

Test a change on a test copy first

Keep a second agent as a test copy. Deploy each change to it first, call it, and deploy the same project to your live agent only once it works. Until then your live agent keeps answering its numbers and widgets with the version it has.

With your coding agent: ask it to create the test copy (agent_create), give it the same variables (agent_set_secrets), deploy the project to it and give you its Playground link. Once your call works, ask it to deploy the same project to the live agent.

From a terminal:

cat .curb/link.json      # "agentId" is your live agent's id: note it
rm .curb/link.json
npx curb secrets push    # choose "Create a new agent" and name it, for example my-agent-test
npx curb deploy          # deploys the test copy and ends with its Playground link

curb secrets push prints the test copy’s id when it creates it. Call the test copy in its Playground. When it works, deploy the same project to the live agent:

npx curb deploy --agent <live-agent-id>

--agent also links the project to the agent you name, so name one on every deploy and secrets push from then on: --agent <test-agent-id> first, then --agent <live-agent-id>.

The test copy needs the same variables as the live agent. Its calls are billed like any other (see pricing). To call it from your phone, add your phone to its test line.

Next steps

• Upgrading: keep Curb up to date.
• Goals and experiments: measure what works on real calls.