{ "$schema": "https://json-schema.org/draft/2020-12/schema", "$id": "https://raw.githubusercontent.com/api-evangelist/frontapp/main/json-schema/frontapp-inbound-message-schema.json", "title": "InboundMessage", "x-generated": "2026-10-14", "x-method": "derived", "x-generator": "derive-json-schema.py", "x-source": "openapi/frontapp-channel-api-openapi.yml#/components/schemas/InboundMessage", "required": [ "sender", "body", "metadata" ], "properties": { "sender": { "type": "object", "description": "Data of the sender", "required": [ "handle" ], "properties": { "name": { "type": "string", "description": "Name of the sender" }, "handle": { "type": "string", "description": "Handle of the sender. It can be any string used to uniquely identify the sender. **Important:** When sending a phone number, include a country code preceded by a plus (+) sign. For example, +33 for France. If you do not send a country code or include a plus sign, Front will normalize your phone number to the USA (+1)." }, "email": { "type": "string", "description": "Email of the sender. When provided, links this contact to existing contacts with the same email to prevent duplicates across channels." } } }, "subject": { "type": "string", "description": "Subject of the message" }, "body": { "type": "string", "description": "The body of the message in HTML or plain text format." }, "metadata": { "type": "object", "required": [ "external_id", "external_conversation_id" ], "properties": { "external_id": { "type": "string", "maxLength": 200, "description": "External identifier of the message" }, "external_conversation_id": { "type": "string", "maxLength": 200, "description": "External identifier of the conversation. Will be used to thread messages." }, "referenced_message_external_id": { "type": "string", "maxLength": 200, "description": "External identifier of the message that this message is replying to. Use this for explicit replies." } } }, "delivered_at": { "type": "integer", "description": "Time in seconds at which message was created in external system" }, "attachments": { "description": "Binary data of attached files. Must use `Content-Type: multipart/form-data` if specified. See [example](https://gist.github.com/hdornier/e04d04921032e98271f46ff8a539a4cb) or read more about [Attachments](https://dev.frontapp.com/docs/attachments-1). Max 25 MB.", "type": "array", "items": { "type": "string", "format": "binary" } } } }