Forward a conversation
Forwards a conversation to one or more recipients as a new email thread.
The API assembles the forwarded chain (Gmail-style
---------- Forwarded message --------- header followed by the full thread),
re-attaches any prior Gmail reply attachments, and hands the workspace's
sending-worker a transport-only job. The worker opens SMTP from the
workspace's dedicated sending IP; it does no composition.
- The first address in
toEmailsbecomes theTo; the rest are prepended tocc. bodyandplainTextare both optional — if omitted, only the forwarded chain is sent. If only one of the two is provided, the server derives the other.fromMailboxIdoverrides the sending mailbox; otherwise the conversation's last-used mailbox is chosen, then any sendable campaign mailbox as a fallback. Mailboxes inactiveorwarming_upstate may be used.- Attachments must have been uploaded via
POST /v1/inbox/attachments/upload(theirkeymust live underinbox-attachments/<workspaceId>/). - Forwards open a new thread: no
In-Reply-To/Referencesheaders are set.
Asynchronous: returns 202 Accepted once the message is recorded on the
conversation and queued. The outbound message appears immediately in
GET /v1/inbox/{conversationId} with sendStatus: "sending". Poll that
endpoint to observe the outcome — it flips to "sent" on delivery, or to
"failed" with a sendError once the worker exhausts its retries.
curl -X POST "https://api.sendkit.ai/v1/inbox/example_string/forward" \
-H "Content-Type: application/json" \
-H "X-Api-Key: YOUR_API_KEY" \
-d '{
"toEmails": [
"colleague@example.com"
],
"body": "<p>FYI — forwarding this thread.</p>"
}'
import requests
import json
url = "https://api.sendkit.ai/v1/inbox/example_string/forward"
headers = {
"Content-Type": "application/json",
"X-Api-Key": "YOUR_API_KEY"
}
data = {
"toEmails": [
"colleague@example.com"
],
"body": "<p>FYI — forwarding this thread.</p>"
}
response = requests.post(url, headers=headers, json=data)
print(response.json())
const response = await fetch("https://api.sendkit.ai/v1/inbox/example_string/forward", {
method: "POST",
headers: {
"Content-Type": "application/json",
"X-Api-Key": "YOUR_API_KEY"
},
body: JSON.stringify({
"toEmails": [
"colleague@example.com"
],
"body": "<p>FYI — forwarding this thread.</p>"
})
});
const data = await response.json();
console.log(data);
package main
import (
"fmt"
"net/http"
"bytes"
"encoding/json"
)
func main() {
data := []byte(`{
"toEmails": [
"colleague@example.com"
],
"body": "<p>FYI — forwarding this thread.</p>"
}`)
req, err := http.NewRequest("POST", "https://api.sendkit.ai/v1/inbox/example_string/forward", bytes.NewBuffer(data))
if err != nil {
panic(err)
}
req.Header.Set("Content-Type", "application/json")
req.Header.Set("X-Api-Key", "YOUR_API_KEY")
client := &http.Client{}
resp, err := client.Do(req)
if err != nil {
panic(err)
}
defer resp.Body.Close()
fmt.Println("Response Status:", resp.Status)
}
require 'net/http'
require 'json'
uri = URI('https://api.sendkit.ai/v1/inbox/example_string/forward')
http = Net::HTTP.new(uri.host, uri.port)
http.use_ssl = true
request = Net::HTTP::Post.new(uri)
request['Content-Type'] = 'application/json'
request['X-Api-Key'] = 'YOUR_API_KEY'
request.body = '{
"toEmails": [
"colleague@example.com"
],
"body": "<p>FYI — forwarding this thread.</p>"
}'
response = http.request(request)
puts response.body
{
"success": true,
"data": {
"jobId": "reply_email_664a1b2c3d4e5f6a7b8c9d01_1748352000123_a1b2c3d",
"messageId": "<9f2c1e64-7b3a-4d21-9a55-3f8e0c1d2b47@example.com>",
"status": "pending",
"to": "colleague@example.com",
"cc": [
"manager@example.com"
],
"bcc": [],
"subject": "Fwd: Quick question about your Q3 roadmap",
"mailbox": {
"id": "664a1b2c3d4e5f6a7b8c9d03",
"email": "sales@example.com"
},
"attachmentsSent": 2,
"message": "Forward queued for sending."
}
}
{
"error": "Bad Request",
"message": "The request contains invalid parameters or malformed data",
"code": 400,
"details": [
{
"field": "email",
"message": "Invalid email format"
}
]
}
{
"error": "Forbidden",
"message": "You don't have permission to access this resource",
"code": 403
}
{
"error": "Not Found",
"message": "The requested resource was not found",
"code": 404
}
/v1/inbox/{conversationId}/forwardTarget server for requests. Edit to use your own host.
Platform API key (sk_user_...) or Workspace API key (sk_...)
Conversation ID (the inbox thread ID)
The media type of the request body
Recipients. First entry becomes To; the rest are prepended to CC.
HTML body of the user's forwarding note. Optional.
Plain-text body of the user's forwarding note. Optional.
Mailbox to send from. Must be active and belong to this workspace.
Attachments from POST /v1/inbox/attachments/upload.
Request Preview
Response
Response will appear here after sending the request
Authentication
API Key for authentication. Platform API key (sk_user_...) or Workspace API key (sk_...)
Path Parameters
Conversation ID (the inbox thread ID)
Body
Recipients. First entry becomes To; the rest are prepended to CC.
HTML body of the user's forwarding note. Optional.
Plain-text body of the user's forwarding note. Optional.
Mailbox to send from. Must be active and belong to this workspace.
Attachments from POST /v1/inbox/attachments/upload.