React to a message
curl --request POST \
--url https://osis.co/api/v1/comms/messages/{message_id}/reactions \
--header 'Authorization: Bearer <token>'import requests
url = "https://osis.co/api/v1/comms/messages/{message_id}/reactions"
headers = {"Authorization": "Bearer <token>"}
response = requests.post(url, headers=headers)
print(response.text)const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};
fetch('https://osis.co/api/v1/comms/messages/{message_id}/reactions', 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://osis.co/api/v1/comms/messages/{message_id}/reactions",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"net/http"
"io"
)
func main() {
url := "https://osis.co/api/v1/comms/messages/{message_id}/reactions"
req, _ := http.NewRequest("POST", url, nil)
req.Header.Add("Authorization", "Bearer <token>")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://osis.co/api/v1/comms/messages/{message_id}/reactions")
.header("Authorization", "Bearer <token>")
.asString();require 'uri'
require 'net/http'
url = URI("https://osis.co/api/v1/comms/messages/{message_id}/reactions")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
response = http.request(request)
puts response.read_bodyMessages
React to a message
POST /api/v1/comms/messages/:id/reactions — add or remove a native iMessage tapback.
POST
https://osis.co
/
api
/
v1
/
comms
/
messages
/
{message_id}
/
reactions
React to a message
curl --request POST \
--url https://osis.co/api/v1/comms/messages/{message_id}/reactions \
--header 'Authorization: Bearer <token>'import requests
url = "https://osis.co/api/v1/comms/messages/{message_id}/reactions"
headers = {"Authorization": "Bearer <token>"}
response = requests.post(url, headers=headers)
print(response.text)const options = {method: 'POST', headers: {Authorization: 'Bearer <token>'}};
fetch('https://osis.co/api/v1/comms/messages/{message_id}/reactions', 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://osis.co/api/v1/comms/messages/{message_id}/reactions",
CURLOPT_RETURNTRANSFER => true,
CURLOPT_ENCODING => "",
CURLOPT_MAXREDIRS => 10,
CURLOPT_TIMEOUT => 30,
CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
CURLOPT_CUSTOMREQUEST => "POST",
CURLOPT_HTTPHEADER => [
"Authorization: Bearer <token>"
],
]);
$response = curl_exec($curl);
$err = curl_error($curl);
curl_close($curl);
if ($err) {
echo "cURL Error #:" . $err;
} else {
echo $response;
}package main
import (
"fmt"
"net/http"
"io"
)
func main() {
url := "https://osis.co/api/v1/comms/messages/{message_id}/reactions"
req, _ := http.NewRequest("POST", url, nil)
req.Header.Add("Authorization", "Bearer <token>")
res, _ := http.DefaultClient.Do(req)
defer res.Body.Close()
body, _ := io.ReadAll(res.Body)
fmt.Println(string(body))
}HttpResponse<String> response = Unirest.post("https://osis.co/api/v1/comms/messages/{message_id}/reactions")
.header("Authorization", "Bearer <token>")
.asString();require 'uri'
require 'net/http'
url = URI("https://osis.co/api/v1/comms/messages/{message_id}/reactions")
http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true
request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
response = http.request(request)
puts response.read_bodyAdd or remove one of the six native iMessage tapbacks on an existing message.
Scope:
Inbound tapbacks still persist and fan out even when outbound is gated.
comms_send
Native types: love, like, dislike, laugh, emphasize, question.
curl -X POST "https://osis.co/api/v1/comms/messages/$MESSAGE_ID/reactions" \
-H "Authorization: Bearer $COMMS_API_KEY" \
-H "Content-Type: application/json" \
-H "Idempotency-Key: love-msg-4242" \
-d '{ "type": "love", "action": "added" }'
action defaults to added. Pass removed to take the tapback off.
Response
202 Accepted
{
"reaction": {
"id": "react_…",
"message_id": "msg_…",
"type": "love",
"emoji": "❤️",
"action": "added",
"actor": {
"kind": "line",
"handle": "+16282646448",
"contact_id": null,
"is_from_me": true
},
"created_at": "2026-08-25T12:00:00.000Z",
"removed_at": null
},
"duplicate": false
}
200 OK (duplicate)
Same idempotency key already processed — no second send.Errors
| Status | Code | Meaning |
|---|---|---|
| 400 | invalid_tapback | type is not one of the six native tapbacks |
| 404 | message_not_found | Message id is not in this workspace |
| 409 | unsupported_transport | SMS, RCS, or a non-iMessage conversation |
| 409 | reactions_outbound_disabled | Outbound tapbacks are gated (canary rollout) |
| 409 | provider_message_unavailable | The bubble has no provider GUID yet |
| 409 | provider_conversation_unavailable | No live iMessage thread id |
⌘I