POST
/threads/{thread_id}/messages/{message_id}Modify a thread message
Updates the metadata associated with a message in a thread. Use thread_id and message_id to select the message, then provide the metadata value to apply.
- RetriesRetries up to 2×, 500ms backoff, 30s timeout.
thread_idstringrequired
The identifier of the thread containing the message.
message_idstringrequired
The identifier of the message to modify.
Message properties to update.
metadataobjectoptional
String key-value pairs attached to the message; keys can be up to 64 characters, with up to 16 pairs, or `null` to clear the metadata.
200Returns the updated message object with its identifier, thread association, status, role, content, attachments, and metadata.
idstringrequired
The identifier, which can be referenced in API endpoints.
objectstringrequired
The object type, which is always `thread.message`.
created_atintegerrequired
The Unix timestamp (in seconds) for when the message was created.
thread_idstringrequired
The [thread](https://developers.openai.com/api/docs/assistants/migration) ID that this message belongs to.
statusstringrequired
The status of the message, which can be either `in_progress`, `incomplete`, or `completed`.
incomplete_detailsobjectrequired
On an incomplete message, details about why the message is incomplete.
completed_atintegerrequired
The Unix timestamp (in seconds) for when the message was completed.
incomplete_atintegerrequired
The Unix timestamp (in seconds) for when the message was marked as incomplete.
rolestringrequired
The entity that produced the message. One of `user` or `assistant`.
contentarray<ImageFile>required
The content of the message in array of text and/or images.
assistant_idstringrequired
If applicable, the ID of the [assistant](https://developers.openai.com/api/docs/assistants/migration) that authored this message.
run_idstringrequired
The ID of the [run](https://developers.openai.com/api/docs/assistants/migration) associated with the creation of this message. Value is `null` when messages are created manually using the create message or create thread endpoints.
attachmentsarray<object>required
A list of files attached to the message, and the tools they were added to.
metadataobjectrequired
Set of 16 key-value pairs that can be attached to an object. This can be
useful for storing additional information about the object in a structured
format, and querying for objects via API or the dashboard.
Keys are strings with a maximum length of 64 characters. Values are strings
with a maximum length of 512 characters.
429Returned when the request was rejected because a rate limit was exceeded.
errorobjectrequired
Error handling
A 429 is returned when the request exceeds the rate limit. thread_id and message_id must identify the message to modify, and metadata uses string values with keys up to 64 characters.