What is a Template?
A Template securely stores Transloadit Assembly Instructions in a Workspace and is referenced in API requests through a template_id. It lets clients invoke a predefined processing workflow without sending its full instructions.
How Templates work
A Transloadit Template is a Workspace-managed workflow definition whose JSON describes named Assembly Steps, their parameters, and how outputs from earlier Steps flow into later ones. Referencing a server-side definition reduces payload duplication and keeps sensitive workflow details away from untrusted clients, but it does not freeze the workflow. Properties supplied in params at request time, except allow_steps_override itself, are recursively merged over the loaded Template. That merge also enables controlled runtime variation. Templates sit between application requests and Assembly execution, so their change management is part of the integration contract.
Key facts
- 1Step names form references within Assembly Instructions, so renaming a step can break downstream
userelationships even when every individual operation remains syntactically valid. - 2A
template_idselects stored instructions but does not by itself authenticate an API request; account authentication and any request-signing requirements remain separate controls. - 3Templates created in a Workspace have no version pinning. To make a backward-incompatible change safely, create a new Template with its own
template_idand move callers over. Only Transloadit’s Builtin Templates are versioned by Transloadit.
When Templates matter
Use a Template to centralize workflow changes and avoid exposing complete Assembly Instructions in clients. To keep callers from altering the workflow, also set allow_steps_override to false and require Signature Authentication, because request params are otherwise merged over the stored instructions at runtime. Updating a shared Template can affect every caller, so incompatible changes may require a new Template.