Troubleshooting

Browser request fails during CORS preflight

The request rejects with a JanuaryError whose category is transport and whose message is "The request failed and the interceptors did not return an alternative response"; the browser console shows a CORS error. January hasn't enabled the page's origin. Ask your January contact to enable the exact scheme, host, and port, and until then make January calls from your server (Runtime and security boundaries). Don't work around it with mode: 'no-cors' or by moving the API key into the browser.

The API key is in the browser bundle

Remove it, rotate the key in the Developer Dashboard, and mint client tokens on your server instead (Backend token endpoint).

Token provider fails

Check the endpoint URL, the app session, CORS on the token endpoint, and the HTTP status and body it returns. The body needs a nonblank token and an expires_in (or expiresIn) over 60 seconds. With the token relay, a browser page also needs its origin in the relay's ALLOWED_ORIGINS (Authentication). How each failure surfaces is in When the provider fails.

Provider is called repeatedly

Reuse one JanuaryClient per signed-in user. A new client starts with an empty token cache. Also check whether the token's lifetime is close to the 60-second refresh window, or whether January answers 401 token_expired.

Data from the previous user appears

The client still holds the previous user's token. Create a new JanuaryClient on sign-in, sign-out, and account switches (Client lifecycle).

Food picker has incomplete servings

After the user picks a search result, call foods.get. Autocomplete and search results are summaries.

preparePhotoScanImage fails in Node.js or SSR

It needs browser image and canvas APIs, so call it only in the browser. On a server, pass analyzePhoto a publicly fetchable image URL or a data URI you prepare there.

Canceled requests look like errors

A canceled request rejects with an AbortError, not a JanuaryError. Check the error's name or your signal's aborted flag before treating it as a failure (Error handling).

Contacting support

See what to include.