Skip to main content
Every object has a Cula-assigned id (for example ste_01k6cvp6bdeayb0hfrghfwxjzv). In addition, some objects let you attach an external ID — your own identifier — so you can cross-reference Cula records with the objects in your systems without storing Cula IDs.

​
Assigning an External ID

Set external_id when you create a object:
Create a site with an external ID
An external ID must be unique within your organisation, be 1–100 characters long, and contain only letters, digits, hyphens, and underscores (A–Z a–z 0–9 - _).
External IDs are mutable — you can change one later. If you need a stable, immutable handle for a object, use the Cula-assigned id instead.

​
Referencing Objects by External ID

Where a request references another object, you can identify it by either its Cula id or its external_id — but not both. For example, when creating a site you can point at its managing organisation by external ID:
Reference by external ID
This lets you build requests entirely from identifiers your own system already knows.

​
Querying by External ID

Endpoints that return a single object accept an external ID in place of the Cula id, using the ext-{your_external_id} path format. This works for every object type that supports external IDs:
Fetch a site by external ID
The ext- prefix is only a lookup convention that distinguishes an external ID from a Cula-assigned id (which uses the {prefix}_... format). The returned object reports its external ID plainly as external_id, without the prefix.

​
How External IDs Are Returned

Responses always include the object’s own external_id (null if none was set), and references to other objects are resolved to carry both identifiers:
Site response