Deployment

When you deploy the application you've embedded Fastn into, the main consideration is how environment variables and secrets bind on your deploy target. Getting this wrong is a common cause of a working local build that fails in production.

Environment variables: runtime vs build time

Your embedded integration needs at least:

• FASTN_API_KEY — your fsk_ API key

• FASTN_END_ORG_ID — the customer UUID

These must be available to the server-side function that generates embed tokens.

On some hosts, environment variables set in a CI pipeline are not automatically available to the deployed runtime. They bind at deploy time on the hosting target, not from the pipeline's own secrets. If the token function reads an undefined API key in production, token generation fails and the embed renders blank.

Checklist for deploying

1. Set FASTN_API_KEY and FASTN_END_ORG_ID directly on the hosting target (not only in CI).

2. Use a fsk_live_ key in production (and drop the X-fastn-Test-Mode header — see Authentication & API Keys).

3. Redeploy after changing environment variables, if your host binds them at deploy time.

4. Paste secret values raw — no surrounding quotes or brackets.

5. Confirm the token endpoint is reachable from your deployed backend.

Verifying after deploy

Load the embedded page in production and confirm the widget renders and a token is being generated fresh on each load. If the iframe is blank, check that the environment variables are bound on the runtime, not just present in CI. See Troubleshooting.