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POST
JavaScript

Authorizations

Authorization
string
header
required

Telnyx API key supplied as Authorization: Bearer <token>. In production, auth may be validated by the API gateway and forwarded via Telnyx auth headers.

Headers

Idempotency-Key
string

Optional opaque, unquoted key for safely retrying the same logical request. Keys must contain 1 to 255 letters, numbers, hyphens, or underscores. Generate a unique UUID v4 for each operation and reuse it only when retrying that operation with the same request. Invalid headers—including duplicate, empty, malformed, or overlong values—return 400 with error code 10015. A request already in progress with the same key returns 409; reusing the key with a different request returns 422. Only successful responses are replayed, for up to 24 hours. Do not include sensitive data in the key.

Required string length: 1 - 255
Pattern: ^[A-Za-z0-9_-]{1,255}$

Body

application/json
name
string
required

Letters, numbers, spaces, hyphens, and underscores only.

Maximum string length: 255
Pattern: ^[A-Za-z0-9 _-]+$
subject
string | null

Liquid template subject.

Maximum string length: 255
html_body
string | null

Liquid template HTML body.

text_body
string | null

Liquid template text body.

variables
string[] | null

Persisted variable names. In automatic mode a non-null array is rejected; in explicit mode this is the exact manual array and each item is limited to 255 Unicode code points.

Maximum string length: 255
variables_mode
enum<string>

Controls how variables is maintained. If both fields are omitted (or variables is null), the template uses automatic mode and extracts variable names from the effective subject, HTML body, and text body. A non-null variables array with no mode selects explicit. automatic rejects a simultaneous non-null array; explicit requires a non-null array, including valid [], and preserves its exact order, duplicates, and string contents.

Available options:
automatic,
explicit
strict_variables
boolean
default:false

Per-template strict variable-validation setting. Defaults to false for backward compatibility. When true, a send or render that is missing a variable marked required: true in variable_schema fails with 422 naming the variable. Missing optional variables never fail; their schema default (when set) is applied to the render.

autoescape
boolean
default:false

Per-template HTML autoescaping setting. Defaults to false for backward compatibility. When true, the rendered html_body HTML-escapes each Liquid expression's output at the output boundary (after its filters run, before concatenation with literal template markup). Input values are never mutated and subject/text_body are never autoescaped. The boundary escape is idempotent: HTML entities already present in the output (e.g. from an explicit escape filter) are preserved, so an explicit escape/escape_once is never double-escaped, and markup introduced by any later filter in the chain is still escaped.

variable_schema
object | null

Structured variable requirements. Required variables cannot define defaults; invalid combinations return 422. This is independent of the legacy variables array. On render with strict_variables enabled: required variables must be supplied as non-empty values — absent, null, empty string, empty object {}, and empty array [] all fail with 422 naming the variable, while present values such as false and 0 pass (they are present, not empty). Optional variables fall back to their default when absent.

Response

Template created.

data
object
required