Retrieve a complete conversation thread containing all chronological…
Retrieve a complete conversation thread containing all chronological messages and replies
Request
- x-api-key: <your-api-key>
- Content-Type: application/json
Response
{
"historyId": "his_363655",
"id": "itm_700934",
"messages": [
{
"date": "2026-09-08",
"from": "ada@example.com",
"id": "itm_700934",
"labelIds": [
"lab_720662"
],
"snippet": "<snippet>",
"subject": "Your September invoice"
}
],
"messagesCount": 3,
"status": "success",
"tokensDeducted": 1
}What it does
Retrieve a complete conversation thread containing all chronological messages and replies
Request
Body
| Field | Type | Required | Description |
|---|---|---|---|
accessToken | string | yes | |
threadId | string | yes |
Example request
{
"accessToken": "<token>",
"threadId": "thr_773061"
}Response
| Field | Type | Description |
|---|---|---|
historyId | string | |
id | string | |
messages | array<object> | |
↳ date | string | |
↳ from | string | |
↳ id | string | |
↳ labelIds | array<string> | |
↳ snippet | string | |
↳ subject | string | |
messagesCount | integer | |
status | string | |
tokensDeducted | integer |
Example response
{
"historyId": "his_363655",
"id": "itm_700934",
"messages": [
{
"date": "2026-09-08",
"from": "ada@example.com",
"id": "itm_700934",
"labelIds": [
"lab_720662"
],
"snippet": "<snippet>",
"subject": "Your September invoice"
}
],
"messagesCount": 3,
"status": "success",
"tokensDeducted": 1
}Errors
Every error answers with the same envelope: an HTTP status, a machine code and a sentence.
400 | The body or a parameter failed validation. The details array names the field. |
401 | No key, a revoked key or a wrong header. Send x-api-key. |
402 | The wallet cannot cover this call. Top up or wait for the monthly grant. |
404 | The resource does not exist, or it is not yours. Both answer identically and cost nothing. |
429 | Over the per-minute quota of your tier. Back off and retry. |
5xx | Upstream refused or timed out. The call is not billed. |
Code
curl -X POST 'https://app.castomapi.com/v1/google/gmail/threads/get' \
-H 'x-api-key: <your-api-key>' \
-H 'Content-Type: application/json' \
-d '{"accessToken": "<token>", "threadId": "thr_773061"}'const res = await fetch('https://app.castomapi.com/v1/google/gmail/threads/get', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"accessToken": "<token>", "threadId": "thr_773061"})
});
const data = await res.json();
console.log(data);import { request } from 'node:https';
// Node 18+ has fetch built in
const res = await fetch('https://app.castomapi.com/v1/google/gmail/threads/get', {
method: 'POST',
headers: { 'x-api-key': '<your-api-key>', 'Content-Type': 'application/json' },
body: JSON.stringify({"accessToken": "<token>", "threadId": "thr_773061"})
});
const data = await res.json();
console.log(data);import requests
res = requests.post(
'https://app.castomapi.com/v1/google/gmail/threads/get',
headers={'x-api-key': '<your-api-key>'},
json={"accessToken": "<token>", "threadId": "thr_773061"},
timeout=30,
)
print(res.json())<?php
$ch = curl_init('https://app.castomapi.com/v1/google/gmail/threads/get');
curl_setopt_array($ch, [
CURLOPT_CUSTOMREQUEST => 'POST',
CURLOPT_RETURNTRANSFER => true,
CURLOPT_HTTPHEADER => ['x-api-key: <your-api-key>', 'Content-Type: application/json'],
CURLOPT_POSTFIELDS => json_encode(['accessToken' => '<token>', 'threadId' => 'thr_773061']),
]);
$data = json_decode(curl_exec($ch), true);
print_r($data);Cost and limits
This operation costs 1 token. A call that fails is never billed. Every account gets 1000 free tokens a month; paid balances never expire.
Rate limits per minute
| No key | 10 |
| Free | 60 |
| Pro | 300 |
| Enterprise | 1200 |
Questions
What does Retrieve a complete conversation thread containing all chronological… cost?
1 token per successful call, debited from your wallet after the response. Failed calls are free. Every account receives 1000 free tokens a month.
How do I authenticate?
Send your key in the x-api-key header. One key covers every metered endpoint; there is nothing to enable per endpoint.
Can I send an Authorization: Bearer token instead?
Not for a metered endpoint — those take the x-api-key header and nothing else. Bearer tokens belong to the account side: the dashboard and account APIs accept a JWT session, and castomapi-auth issues those through a standard OAuth2 handshake, with authorization code, client credentials and refresh grants. The auth service page covers it.
What are the limits?
10 requests a minute per IP with no key at all, 60 a minute on the free tier, 300 on Pro, 1200 on Enterprise. Above the no-key tier the quota is per account, across every endpoint.
OpenAPI: https://app.castomapi.com/docs/json