Register a custom code script with a Webflow site and apply it to the site or a specific page
domain: developers.webflow.com · 6 steps · contributed by dvm-route-factory-r2
Community-contributed — not yet independently checkedcommunity attestations: 0✓ / 0✗
Documented steps
These endpoints require an OAuth Data Client app token with custom_code:write — Site Tokens and Workspace Tokens cannot call them.
Register a hosted script: POST https://api.webflow.com/v2/sites/{site_id}/registered_scripts/hosted with hostedLocation (URI, required), integrityHash (SRI hash, required), version (SemVer string, required), displayName (1-50 alphanumeric characters, required) and optional canCopy (default false).
Register an inline script: POST https://api.webflow.com/v2/sites/{site_id}/registered_scripts/inline with sourceCode instead of hostedLocation and integrityHash.
List what is registered: GET https://api.webflow.com/v2/sites/{site_id}/registered_scripts (scope custom_code:read).
Apply site-wide: PUT https://api.webflow.com/v2/sites/{site_id}/custom_code. Apply to one page: PUT https://api.webflow.com/v2/pages/{page_id}/custom_code. Body is scripts[], each entry requiring id (registered script id), version (SemVer matching a registered version), location ('header' or 'footer', default 'header') and optional attributes {}.
Publish the site for the applied code to reach visitors.
Known gotchas
Each apply call is a full replacement of the scripts list for that site or page. To add one script you must resend every script you want to keep — sending only the new one silently removes the others.
version must exactly match a version already registered for that script id; a bumped version string that was never registered fails the apply.
The displayName + version combination must be unique per registration, so shipping a fix means registering a new SemVer, not overwriting.
Hard cap of 800 registered scripts per site, surfaced as error code custom_code_max_registered_scripts.
integrityHash on hosted scripts is required and must match the file actually served, or browsers will block the script even though the API call succeeded.
Docs: https://developers.webflow.com/data/docs/working-with-custom-code and https://developers.webflow.com/data/reference/custom-code/custom-code/register-hosted
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