Messaging
Send a message
Sends a text message through the same writer every other client uses, so delivery, push and the conversation’s state update as they do there. A contact conversation sends email or SMS. A conversation the member cannot post to (a broadcast-only channel, an archived or closed conversation, or one the member has archived for themselves) returns 403.
A retry with the same client_message_id returns the message already sent, even when the
conversation has closed since. If that message was deleted, the response carries no text or
attachments.
POST
/
api
/
member
/
v2026-10
/
messaging
/
conversations
/
{id}
/
messages
Send a message
curl --request POST \
--url https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"text": "See you at the kickoff.",
"client_message_id": "7f1c2b9e-launch"
}
'import requests
url = "https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages"
payload = {
"text": "See you at the kickoff.",
"client_message_id": "7f1c2b9e-launch"
}
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({text: 'See you at the kickoff.', client_message_id: '7f1c2b9e-launch'})
};
fetch('https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'text' => 'See you at the kickoff.',
'client_message_id' => '7f1c2b9e-launch'
]),
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages"
payload := strings.NewReader("{\n \"text\": \"See you at the kickoff.\",\n \"client_message_id\": \"7f1c2b9e-launch\"\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"text\": \"See you at the kickoff.\",\n \"client_message_id\": \"7f1c2b9e-launch\"\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"text\": \"See you at the kickoff.\",\n \"client_message_id\": \"7f1c2b9e-launch\"\n}"
response = http.request(request)
puts response.read_body{
"status": 200,
"data": {
"id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a60",
"conversation_id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a5b",
"sender": {
"id": "01a08944-eff4-7a2a-be01-d699fa649966",
"kind": "member",
"name": "Nathan Rivera",
"avatar_url": null
},
"kind": "message",
"text": "See you at the kickoff.",
"event": null,
"attachments": [],
"reply_to": null,
"reactions": [
{
"emoji": "👍",
"count": 2,
"mine": true
}
],
"pinned": false,
"seen_by_count": 3,
"client_message_id": "7f1c2b9e-launch",
"sent_at": "2026-10-01T15:02:00Z",
"created_at": "2026-10-01T15:01:59Z",
"edited_at": null
},
"meta": {
"request_uuid": "01a0f4fe-de00-75b3-8d8a-b74b0cde8b07",
"timestamp": "2026-10-01T15:04:05Z"
}
}{
"status": 201,
"data": {
"id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a60",
"conversation_id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a5b",
"sender": {
"id": "01a08944-eff4-7a2a-be01-d699fa649966",
"kind": "member",
"name": "Nathan Rivera",
"avatar_url": null
},
"kind": "message",
"text": "See you at the kickoff.",
"event": null,
"attachments": [],
"reply_to": null,
"reactions": [
{
"emoji": "👍",
"count": 2,
"mine": true
}
],
"pinned": false,
"seen_by_count": 3,
"client_message_id": "7f1c2b9e-launch",
"sent_at": "2026-10-01T15:02:00Z",
"created_at": "2026-10-01T15:01:59Z",
"edited_at": null
},
"meta": {
"request_uuid": "01a0f4fe-de00-75b3-8d8a-b74b0cde8b07",
"timestamp": "2026-10-01T15:04:05Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}Authorizations
A member credential in the Authorization: Bearer header: a member
session JWT, a portal JWT whose login is linked to a membership in
that company, or a member token. The credential alone
identifies the member and company.
Path Parameters
Public id of a conversation the member can see.
Body
application/json
- Option 1
- Option 2
Required unless the message has attachments.
Required string length:
1 - 10000Pattern:
\SA message in this conversation the member can read.
An id the client chooses. A retry with the same id returns the message already sent, with 200, instead of sending it again.
Required string length:
1 - 100Files the client has uploaded, named by URL, as the legacy message endpoint takes them. The URL is not checked as an owned upload.
Maximum array length:
10Show child attributes
Show child attributes
Response
The message already sent with this client_message_id, without text or attachments if it was deleted.
⌘I
Send a message
curl --request POST \
--url https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages \
--header 'Authorization: Bearer <token>' \
--header 'Content-Type: application/json' \
--data '
{
"text": "See you at the kickoff.",
"client_message_id": "7f1c2b9e-launch"
}
'import requests
url = "https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages"
payload = {
"text": "See you at the kickoff.",
"client_message_id": "7f1c2b9e-launch"
}
headers = {
"Authorization": "Bearer <token>",
"Content-Type": "application/json"
}
response = requests.post(url, json=payload, headers=headers)
print(response.text)const options = {
method: 'POST',
headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
body: JSON.stringify({text: 'See you at the kickoff.', client_message_id: '7f1c2b9e-launch'})
};
fetch('https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages', options)
.then(res => res.json())
.then(res => console.log(res))
.catch(err => console.error(err));<?php
$curl = curl_init();
curl_setopt_array($curl, [
CURLOPT_URL => "https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_POSTFIELDS => json_encode([
'text' => 'See you at the kickoff.',
'client_message_id' => '7f1c2b9e-launch'
]),
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>",
"Content-Type: application/json"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"strings"
"net/http"
"io"
)
func main() {
url := "https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages"
payload := strings.NewReader("{\n \"text\": \"See you at the kickoff.\",\n \"client_message_id\": \"7f1c2b9e-launch\"\n}")
req, _ := http.NewRequest("POST", url, payload)
req.Header.Add("Authorization", "Bearer <token>")
req.Header.Add("Content-Type", "application/json")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages")
.header("Authorization", "Bearer <token>")
.header("Content-Type", "application/json")
.body("{\n \"text\": \"See you at the kickoff.\",\n \"client_message_id\": \"7f1c2b9e-launch\"\n}")
.asString();require 'uri'
require 'net/http'
url = URI("https://api.fluid.app/api/member/v2026-10/messaging/conversations/{id}/messages")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n \"text\": \"See you at the kickoff.\",\n \"client_message_id\": \"7f1c2b9e-launch\"\n}"
response = http.request(request)
puts response.read_body{
"status": 200,
"data": {
"id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a60",
"conversation_id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a5b",
"sender": {
"id": "01a08944-eff4-7a2a-be01-d699fa649966",
"kind": "member",
"name": "Nathan Rivera",
"avatar_url": null
},
"kind": "message",
"text": "See you at the kickoff.",
"event": null,
"attachments": [],
"reply_to": null,
"reactions": [
{
"emoji": "👍",
"count": 2,
"mine": true
}
],
"pinned": false,
"seen_by_count": 3,
"client_message_id": "7f1c2b9e-launch",
"sent_at": "2026-10-01T15:02:00Z",
"created_at": "2026-10-01T15:01:59Z",
"edited_at": null
},
"meta": {
"request_uuid": "01a0f4fe-de00-75b3-8d8a-b74b0cde8b07",
"timestamp": "2026-10-01T15:04:05Z"
}
}{
"status": 201,
"data": {
"id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a60",
"conversation_id": "0199a1b2-c3d4-7e5f-8a9b-0c1d2e3f4a5b",
"sender": {
"id": "01a08944-eff4-7a2a-be01-d699fa649966",
"kind": "member",
"name": "Nathan Rivera",
"avatar_url": null
},
"kind": "message",
"text": "See you at the kickoff.",
"event": null,
"attachments": [],
"reply_to": null,
"reactions": [
{
"emoji": "👍",
"count": 2,
"mine": true
}
],
"pinned": false,
"seen_by_count": 3,
"client_message_id": "7f1c2b9e-launch",
"sent_at": "2026-10-01T15:02:00Z",
"created_at": "2026-10-01T15:01:59Z",
"edited_at": null
},
"meta": {
"request_uuid": "01a0f4fe-de00-75b3-8d8a-b74b0cde8b07",
"timestamp": "2026-10-01T15:04:05Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}{
"status": 123,
"error": {
"message": "<string>",
"details": {}
},
"meta": {
"request_uuid": "3c90c3cc-0d44-4b50-8888-8dd25736052a",
"timestamp": "2023-11-07T05:31:56Z"
}
}