Can I Stream Message Events from the Assistants API?

Below is an explanation of how streaming works with Assistants:

Streaming in the Assistants API

Streaming is supported for both the Chat Completions API and the Assistants API. When an Assistant generates a message, the API doesn't simply return a fully-formed response immediately. Instead, it emits a sequence of events. For a message, you’ll typically see:

• thread.message.created: Indicates that the message creation process has started.
• thread.message.in_progress: Signals that the message is currently being built.
• thread.message.delta: One or more events containing incremental parts of the message.
• thread.message.completed: Indicates that the message stream has finished.

What This Means for Your Use Case

Even though it might seem like direct streaming of completed messages isn’t available, streaming is indeed happening. You can receive partial results as they’re emitted (via the delta events) and reconstruct the full message in real time. In other words, you’ll be extracting the message content from the thread events (especially from the delta events) rather than waiting for a single complete output.

Final Note

The design encourages handling these events gracefully. The API may emit new event types in the future, so it’s recommended that your implementation accounts for any events that might be added later.

If you have further questions or need more details on implementation, feel free to ask.