# Can't update a topic's body by API
**URL:** https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640
**Category:** Development
**Tags:** rest-api
**Created:** [May 11, 2023, 12:05pm UTC](https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640 "2023-05-11T12:05:50Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@Dotila\_Li](https://meta.discourse.org/u/Dotila_Li)
#### Post date: [May 11, 2023, 12:05pm UTC](https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640/1 "2023-05-11T12:05:50Z")
I did follow the [docs](https://docs.discourse.org/#tag/Topics/operation/updateTopic) and， however, it only update the topic’s title, without updating the body.
My code (Javascript):
```js
async function updateDiscourseTopic(topic_id) {
const Discourse_API_Key = "Discourse_API_Key";
const url = `https://discourse.mysite.com/t/-/${topic_id}.json`;
const payload = {
title: 'session_1',
raw: "new body(doesn't apply)"
}
const response = await fetch(url, {
method: 'PUT',
headers: {
"Api-Key": Discourse_API_Key,
"Api-Username": "system",
"Content-Type": "application/json",
},
body: JSON.stringify(payload)
});
}
```
---
### Author:  [@Lilly](https://meta.discourse.org/u/Lilly)
#### Post date: [May 11, 2023, 1:01pm UTC](https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640/2 "2023-05-11T13:01:55Z")
just a guess from looking at the code, but perhaps it may be because you are using `topic_id` instead of `post_id`? because first post is the topic in Discourse, more or less?
---
### Author:  [@Canapin](https://meta.discourse.org/u/Canapin)
#### Post date: [May 11, 2023, 3:31pm UTC](https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640/3 "2023-05-11T15:31:52Z")
@Lilly’s right.
A _topic_ is defined by attributes like title, category, tags, etc.
But the content belongs to a _post_.
If you want to update the title and the content, you need 2 requests.
1. PUT on the topic
2. PUT on the first post. You can find the post’s ID in the HTML code of the page. Look for the `data-post-id` attribute in ``.
Example:
---
### Author:  [@Dotila\_Li](https://meta.discourse.org/u/Dotila_Li)
#### Post date: [May 11, 2023, 4:11pm UTC](https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640/4 "2023-05-11T16:11:39Z")
Wow, you are right, it works 💖
And I figured out how to retrieve the ID of the first post in a topic using the Discourse API:
```js
async function getFirstPostIdFromOnetopic(topic_id) {
const Discourse_API_Key = "Discourse_API_Key";
const url = `https://discourse.mysite.com/t/${topic_id}/posts.json`;
const response = await fetch(url, {
method: 'GET',
headers: {
"Api-Key": Discourse_API_Key,
"Api-Username": "system",
"Content-Type": "application/json",
}
});
const data = await response.json();
const firstPostId = data.post_stream.posts[0].id;
return firstPostId;
}
```
Thank you and @Lilly 😇
---
### Author:  [@system](https://meta.discourse.org/u/system)
#### Post date: [June 10, 2023, 4:12pm UTC](https://meta.discourse.org/t/cant-update-a-topics-body-by-api/264640/5 "2023-06-10T16:12:19Z")
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