API errors | SendLit Docs

SendLit returns JSON errors with a stable error string. Clients should branch on the code rather than human-readable descriptions.

Status	Error	Meaning
`422`	`template_not_transactional`	`POST /emails` received a marketing template.
`422`	`template_not_marketing`	A broadcast or sequence received a transactional template.
`422`	`missing_template_variables`	Required Liquid paths were absent from `variables`.
`422`	`template_conversion_requires_changes`	Marketing-only references remain outside the managed footer.
`422`	`footer_required`	Marketing content does not contain exactly one final managed footer.
`422`	`footer_not_allowed`	Transactional content contains a managed footer.
`422`	`marketing_variables_not_allowed`	Transactional content references marketing-owned values.

Missing and conversion errors include the affected paths:

{
    "error": "missing_template_variables",
    "missingVariables": ["customer.name", "otp"]
}

{
    "error": "template_conversion_requires_changes",
    "variables": ["subscriber.name"]
}

All template-purpose, structural, and missing-variable checks happen before an email is queued. A rejected request does not create a partial destination template or transactional delivery.