---
title: "Send a message"
method: POST
path: "/messages"
tags: ["Messages"]
---

# Send a message

`POST /messages`

## Request

- Base URL: `https://sumgenius.ai/api/v1`
- URL: `https://sumgenius.ai/api/v1/messages`
- Auth: one of:
  - API key in header `X-SumGenius-Api-Key`
  - HTTP bearer

Send text, a WhatsApp template, a reaction, or a typing indicator on any channel. Route by conversation_id, by platform plus platform_user_id, or by to_phone for SMS and WhatsApp. SMS, WhatsApp and Telegram can start a conversation cold; Facebook and Instagram need an inbound message first. idempotency_key is required in the body, or send the Idempotency-Key header. Requires the `write` scope.

## Request body

- SendMessage: One routing method is required: conversation_id, or platform plus platform_user_id, or to_phone.
  - `idempotency_key` string: Required unless the Idempotency-Key header is sent. A replay returns the original result with status duplicate.
  - `action` 'send_message' | 'react' | 'unreact' | 'typing_on'
  - `conversation_id` integer: Route by conversation.
  - `platform` 'facebook' | 'instagram' | 'sms' | 'telegram' | 'whatsapp': With platform_user_id, route by the channel identity.
  - `platform_user_id` string
  - `to_phone` string: E.164. SMS and WhatsApp only. Starts a conversation if none exists.
  - `message_text` string: For send_message.
  - `template_name` string: WhatsApp template, outside the 24-hour window.
  - `template_language` string
  - `template_components` object[]
  - `target_message_id` string: For react and unreact.
  - `reaction` string: For react, for example love.

## Response `200`

Accepted

- object
  - `data` SendResult, required
    - `status` 'sent' | 'queued_retry' | 'duplicate'
    - `request_id` string, nullable
    - `conversation_id` integer, nullable
    - `platform` 'facebook' | 'instagram' | 'sms' | 'telegram' | 'whatsapp' | 'null', nullable
    - `action` 'send_message' | 'react' | 'unreact' | 'typing_on'
    - `target_message_id` string, nullable
    - `reaction` string, nullable
    - `meta_message_id` string, nullable
    - `sent_at` string, date-time, nullable: UTC ISO-8601.
    - `message` string
    - `to_phone` string
    - `whatsapp_message_id` string, nullable
    - `message_kind` string, nullable
    - `template_name` string, nullable

## Other responses

- `400`: Error envelope. Codes: `invalid_param`: 400 a parameter or body field failed validation; `param` names it `invalid_json`: 400 the body is not valid JSON `invalid_idempotency_key`: 400 Idempotency-Key is not 1 to 128 printable ASCII characters `unauthorized`: 401 no API key sent `invalid_api_key`: 401 the key is not recognised `addon_inactive`: 403 the key is valid but the Webhook & API add-on is not active `insufficient_scope`: 403 the key scope does not cover this endpoint; carries `required_scope` and `key_scope` `feature_unavailable`: 403 the plan does not include this feature; `param` names it `already_blocked`: 409 that person is already on the AI blocklist `plan_limit_reached`: 403 the plan cap for this resource is reached (for example knowledge base items) `already_member`: 409 that email is already a team member `limit_reached`: 409 the product cap for this resource is reached (3 webhook endpoints, 10 active keys); remove one first `cannot_revoke_self`: 409 a key cannot revoke itself `too_soon`: 429 the same invitation was resent moments ago; the message says how long to wait `governance_incomplete`: 422 the endpoint cannot go live until its data-sharing declaration is attested with a purpose `invitation_pending`: 409 that email already has a pending invitation; resend or cancel it `not_found`: 404 missing, or not owned by your account `method_not_allowed`: 405 wrong method; the Allow header lists valid ones `idempotency_in_progress`: 409 a request with this Idempotency-Key is still running `resume_blocked`: 409 the AI pause on this conversation was set by a solicitation pause, a fraud flag or a connected-account pause; lift it from the portal `blocked`: 409 the customer is on the AI blocklist `opted_out`: 409 the customer opted out of automated messages `window_closed`: 409 the Meta messaging window for this conversation has closed `purge_active`: 409 SMS AI cannot be switched on while inbound body purge is on `sms_not_ready`: 409 SMS AI cannot be switched on until carrier registration assigns a Messaging Service `idempotency_key_reused`: 422 same Idempotency-Key, different request `unprocessable_send`: 422 a send was permanently rejected by the channel `rate_limited`: 429 quota or burst ceiling reached; Retry-After is set `service_unavailable`: 503 temporary failure; retry as directed `server_error`: 500 unexpected failure on our side `flow_conflict`: The trigger cannot be activated because of its linked flows: more than one, a paused one, or a broken link. The message says which. `not_connected`: The channel you asked about is not connected to this account. `not_pending`: The comment reply is not waiting for approval (already sent, rejected, or never queued). `send_failed`: 422 Meta refused the reply. The row is marked failed; the message has the reason. `slot_unavailable`: The requested time is outside business hours or already booked. The message says which. `missing_fields`: The account requires customer details this booking did not include; missing_fields lists them. `already_cancelled`: The appointment is already cancelled. `not_active`: Only a pending or confirmed appointment can be rescheduled. `not_editable`: The post is in a status that does not allow this: only draft, scheduled and failed posts can be edited or scheduled; published posts cannot be deleted; only scheduled posts can be unscheduled; only failed posts can be retried. `publish_failed`: 422 a platform rejected the post. The row is now failed; post.error_message and results say why. Retry with POST /posts/{id}/retry. `invalid_definition`: 422 the flow definition failed validation; errors lists every problem, warnings the non-blocking ones. `flow_blocked`: 409 the flow manager refused the action (for example no published version yet, a linked comment trigger in use, or a draft edited elsewhere); the message says why. `conflict`: 409 the draft was edited elsewhere since it was read.
- `401`: Error envelope. Codes: `invalid_param`: 400 a parameter or body field failed validation; `param` names it `invalid_json`: 400 the body is not valid JSON `invalid_idempotency_key`: 400 Idempotency-Key is not 1 to 128 printable ASCII characters `unauthorized`: 401 no API key sent `invalid_api_key`: 401 the key is not recognised `addon_inactive`: 403 the key is valid but the Webhook & API add-on is not active `insufficient_scope`: 403 the key scope does not cover this endpoint; carries `required_scope` and `key_scope` `feature_unavailable`: 403 the plan does not include this feature; `param` names it `already_blocked`: 409 that person is already on the AI blocklist `plan_limit_reached`: 403 the plan cap for this resource is reached (for example knowledge base items) `already_member`: 409 that email is already a team member `limit_reached`: 409 the product cap for this resource is reached (3 webhook endpoints, 10 active keys); remove one first `cannot_revoke_self`: 409 a key cannot revoke itself `too_soon`: 429 the same invitation was resent moments ago; the message says how long to wait `governance_incomplete`: 422 the endpoint cannot go live until its data-sharing declaration is attested with a purpose `invitation_pending`: 409 that email already has a pending invitation; resend or cancel it `not_found`: 404 missing, or not owned by your account `method_not_allowed`: 405 wrong method; the Allow header lists valid ones `idempotency_in_progress`: 409 a request with this Idempotency-Key is still running `resume_blocked`: 409 the AI pause on this conversation was set by a solicitation pause, a fraud flag or a connected-account pause; lift it from the portal `blocked`: 409 the customer is on the AI blocklist `opted_out`: 409 the customer opted out of automated messages `window_closed`: 409 the Meta messaging window for this conversation has closed `purge_active`: 409 SMS AI cannot be switched on while inbound body purge is on `sms_not_ready`: 409 SMS AI cannot be switched on until carrier registration assigns a Messaging Service `idempotency_key_reused`: 422 same Idempotency-Key, different request `unprocessable_send`: 422 a send was permanently rejected by the channel `rate_limited`: 429 quota or burst ceiling reached; Retry-After is set `service_unavailable`: 503 temporary failure; retry as directed `server_error`: 500 unexpected failure on our side `flow_conflict`: The trigger cannot be activated because of its linked flows: more than one, a paused one, or a broken link. The message says which. `not_connected`: The channel you asked about is not connected to this account. `not_pending`: The comment reply is not waiting for approval (already sent, rejected, or never queued). `send_failed`: 422 Meta refused the reply. The row is marked failed; the message has the reason. `slot_unavailable`: The requested time is outside business hours or already booked. The message says which. `missing_fields`: The account requires customer details this booking did not include; missing_fields lists them. `already_cancelled`: The appointment is already cancelled. `not_active`: Only a pending or confirmed appointment can be rescheduled. `not_editable`: The post is in a status that does not allow this: only draft, scheduled and failed posts can be edited or scheduled; published posts cannot be deleted; only scheduled posts can be unscheduled; only failed posts can be retried. `publish_failed`: 422 a platform rejected the post. The row is now failed; post.error_message and results say why. Retry with POST /posts/{id}/retry. `invalid_definition`: 422 the flow definition failed validation; errors lists every problem, warnings the non-blocking ones. `flow_blocked`: 409 the flow manager refused the action (for example no published version yet, a linked comment trigger in use, or a draft edited elsewhere); the message says why. `conflict`: 409 the draft was edited elsewhere since it was read.
- `403`: Error envelope. Codes: `invalid_param`: 400 a parameter or body field failed validation; `param` names it `invalid_json`: 400 the body is not valid JSON `invalid_idempotency_key`: 400 Idempotency-Key is not 1 to 128 printable ASCII characters `unauthorized`: 401 no API key sent `invalid_api_key`: 401 the key is not recognised `addon_inactive`: 403 the key is valid but the Webhook & API add-on is not active `insufficient_scope`: 403 the key scope does not cover this endpoint; carries `required_scope` and `key_scope` `feature_unavailable`: 403 the plan does not include this feature; `param` names it `already_blocked`: 409 that person is already on the AI blocklist `plan_limit_reached`: 403 the plan cap for this resource is reached (for example knowledge base items) `already_member`: 409 that email is already a team member `limit_reached`: 409 the product cap for this resource is reached (3 webhook endpoints, 10 active keys); remove one first `cannot_revoke_self`: 409 a key cannot revoke itself `too_soon`: 429 the same invitation was resent moments ago; the message says how long to wait `governance_incomplete`: 422 the endpoint cannot go live until its data-sharing declaration is attested with a purpose `invitation_pending`: 409 that email already has a pending invitation; resend or cancel it `not_found`: 404 missing, or not owned by your account `method_not_allowed`: 405 wrong method; the Allow header lists valid ones `idempotency_in_progress`: 409 a request with this Idempotency-Key is still running `resume_blocked`: 409 the AI pause on this conversation was set by a solicitation pause, a fraud flag or a connected-account pause; lift it from the portal `blocked`: 409 the customer is on the AI blocklist `opted_out`: 409 the customer opted out of automated messages `window_closed`: 409 the Meta messaging window for this conversation has closed `purge_active`: 409 SMS AI cannot be switched on while inbound body purge is on `sms_not_ready`: 409 SMS AI cannot be switched on until carrier registration assigns a Messaging Service `idempotency_key_reused`: 422 same Idempotency-Key, different request `unprocessable_send`: 422 a send was permanently rejected by the channel `rate_limited`: 429 quota or burst ceiling reached; Retry-After is set `service_unavailable`: 503 temporary failure; retry as directed `server_error`: 500 unexpected failure on our side `flow_conflict`: The trigger cannot be activated because of its linked flows: more than one, a paused one, or a broken link. The message says which. `not_connected`: The channel you asked about is not connected to this account. `not_pending`: The comment reply is not waiting for approval (already sent, rejected, or never queued). `send_failed`: 422 Meta refused the reply. The row is marked failed; the message has the reason. `slot_unavailable`: The requested time is outside business hours or already booked. The message says which. `missing_fields`: The account requires customer details this booking did not include; missing_fields lists them. `already_cancelled`: The appointment is already cancelled. `not_active`: Only a pending or confirmed appointment can be rescheduled. `not_editable`: The post is in a status that does not allow this: only draft, scheduled and failed posts can be edited or scheduled; published posts cannot be deleted; only scheduled posts can be unscheduled; only failed posts can be retried. `publish_failed`: 422 a platform rejected the post. The row is now failed; post.error_message and results say why. Retry with POST /posts/{id}/retry. `invalid_definition`: 422 the flow definition failed validation; errors lists every problem, warnings the non-blocking ones. `flow_blocked`: 409 the flow manager refused the action (for example no published version yet, a linked comment trigger in use, or a draft edited elsewhere); the message says why. `conflict`: 409 the draft was edited elsewhere since it was read.
- `404`: Error envelope. Codes: `invalid_param`: 400 a parameter or body field failed validation; `param` names it `invalid_json`: 400 the body is not valid JSON `invalid_idempotency_key`: 400 Idempotency-Key is not 1 to 128 printable ASCII characters `unauthorized`: 401 no API key sent `invalid_api_key`: 401 the key is not recognised `addon_inactive`: 403 the key is valid but the Webhook & API add-on is not active `insufficient_scope`: 403 the key scope does not cover this endpoint; carries `required_scope` and `key_scope` `feature_unavailable`: 403 the plan does not include this feature; `param` names it `already_blocked`: 409 that person is already on the AI blocklist `plan_limit_reached`: 403 the plan cap for this resource is reached (for example knowledge base items) `already_member`: 409 that email is already a team member `limit_reached`: 409 the product cap for this resource is reached (3 webhook endpoints, 10 active keys); remove one first `cannot_revoke_self`: 409 a key cannot revoke itself `too_soon`: 429 the same invitation was resent moments ago; the message says how long to wait `governance_incomplete`: 422 the endpoint cannot go live until its data-sharing declaration is attested with a purpose `invitation_pending`: 409 that email already has a pending invitation; resend or cancel it `not_found`: 404 missing, or not owned by your account `method_not_allowed`: 405 wrong method; the Allow header lists valid ones `idempotency_in_progress`: 409 a request with this Idempotency-Key is still running `resume_blocked`: 409 the AI pause on this conversation was set by a solicitation pause, a fraud flag or a connected-account pause; lift it from the portal `blocked`: 409 the customer is on the AI blocklist `opted_out`: 409 the customer opted out of automated messages `window_closed`: 409 the Meta messaging window for this conversation has closed `purge_active`: 409 SMS AI cannot be switched on while inbound body purge is on `sms_not_ready`: 409 SMS AI cannot be switched on until carrier registration assigns a Messaging Service `idempotency_key_reused`: 422 same Idempotency-Key, different request `unprocessable_send`: 422 a send was permanently rejected by the channel `rate_limited`: 429 quota or burst ceiling reached; Retry-After is set `service_unavailable`: 503 temporary failure; retry as directed `server_error`: 500 unexpected failure on our side `flow_conflict`: The trigger cannot be activated because of its linked flows: more than one, a paused one, or a broken link. The message says which. `not_connected`: The channel you asked about is not connected to this account. `not_pending`: The comment reply is not waiting for approval (already sent, rejected, or never queued). `send_failed`: 422 Meta refused the reply. The row is marked failed; the message has the reason. `slot_unavailable`: The requested time is outside business hours or already booked. The message says which. `missing_fields`: The account requires customer details this booking did not include; missing_fields lists them. `already_cancelled`: The appointment is already cancelled. `not_active`: Only a pending or confirmed appointment can be rescheduled. `not_editable`: The post is in a status that does not allow this: only draft, scheduled and failed posts can be edited or scheduled; published posts cannot be deleted; only scheduled posts can be unscheduled; only failed posts can be retried. `publish_failed`: 422 a platform rejected the post. The row is now failed; post.error_message and results say why. Retry with POST /posts/{id}/retry. `invalid_definition`: 422 the flow definition failed validation; errors lists every problem, warnings the non-blocking ones. `flow_blocked`: 409 the flow manager refused the action (for example no published version yet, a linked comment trigger in use, or a draft edited elsewhere); the message says why. `conflict`: 409 the draft was edited elsewhere since it was read.
- `410`: The recipient opted out.
- `412`: The channel is not provisioned on this account.
- `422`: Permanently rejected by the channel, for example a reaction on Telegram or an expired messaging window.
- `429`: Error envelope. Codes: `invalid_param`: 400 a parameter or body field failed validation; `param` names it `invalid_json`: 400 the body is not valid JSON `invalid_idempotency_key`: 400 Idempotency-Key is not 1 to 128 printable ASCII characters `unauthorized`: 401 no API key sent `invalid_api_key`: 401 the key is not recognised `addon_inactive`: 403 the key is valid but the Webhook & API add-on is not active `insufficient_scope`: 403 the key scope does not cover this endpoint; carries `required_scope` and `key_scope` `feature_unavailable`: 403 the plan does not include this feature; `param` names it `already_blocked`: 409 that person is already on the AI blocklist `plan_limit_reached`: 403 the plan cap for this resource is reached (for example knowledge base items) `already_member`: 409 that email is already a team member `limit_reached`: 409 the product cap for this resource is reached (3 webhook endpoints, 10 active keys); remove one first `cannot_revoke_self`: 409 a key cannot revoke itself `too_soon`: 429 the same invitation was resent moments ago; the message says how long to wait `governance_incomplete`: 422 the endpoint cannot go live until its data-sharing declaration is attested with a purpose `invitation_pending`: 409 that email already has a pending invitation; resend or cancel it `not_found`: 404 missing, or not owned by your account `method_not_allowed`: 405 wrong method; the Allow header lists valid ones `idempotency_in_progress`: 409 a request with this Idempotency-Key is still running `resume_blocked`: 409 the AI pause on this conversation was set by a solicitation pause, a fraud flag or a connected-account pause; lift it from the portal `blocked`: 409 the customer is on the AI blocklist `opted_out`: 409 the customer opted out of automated messages `window_closed`: 409 the Meta messaging window for this conversation has closed `purge_active`: 409 SMS AI cannot be switched on while inbound body purge is on `sms_not_ready`: 409 SMS AI cannot be switched on until carrier registration assigns a Messaging Service `idempotency_key_reused`: 422 same Idempotency-Key, different request `unprocessable_send`: 422 a send was permanently rejected by the channel `rate_limited`: 429 quota or burst ceiling reached; Retry-After is set `service_unavailable`: 503 temporary failure; retry as directed `server_error`: 500 unexpected failure on our side `flow_conflict`: The trigger cannot be activated because of its linked flows: more than one, a paused one, or a broken link. The message says which. `not_connected`: The channel you asked about is not connected to this account. `not_pending`: The comment reply is not waiting for approval (already sent, rejected, or never queued). `send_failed`: 422 Meta refused the reply. The row is marked failed; the message has the reason. `slot_unavailable`: The requested time is outside business hours or already booked. The message says which. `missing_fields`: The account requires customer details this booking did not include; missing_fields lists them. `already_cancelled`: The appointment is already cancelled. `not_active`: Only a pending or confirmed appointment can be rescheduled. `not_editable`: The post is in a status that does not allow this: only draft, scheduled and failed posts can be edited or scheduled; published posts cannot be deleted; only scheduled posts can be unscheduled; only failed posts can be retried. `publish_failed`: 422 a platform rejected the post. The row is now failed; post.error_message and results say why. Retry with POST /posts/{id}/retry. `invalid_definition`: 422 the flow definition failed validation; errors lists every problem, warnings the non-blocking ones. `flow_blocked`: 409 the flow manager refused the action (for example no published version yet, a linked comment trigger in use, or a draft edited elsewhere); the message says why. `conflict`: 409 the draft was edited elsewhere since it was read.

---

[API](https://skmtc.dev/sumgenius/apis/chatgenius-rest-api.md) · [All operations](https://skmtc.dev/sumgenius/apis/chatgenius-rest-api/llms.txt) · [OpenAPI document](https://skmtc.dev/sumgenius/apis/chatgenius-rest-api/revisions/f1621a748e6f?raw)