Responses API with MCP and Deep research in background mode

API
1

Hi!

I’ve been building out a test case for the new O3 deep research model and I have a strange issue where if I set background to True and try and give the model a remote MCP tool it throws this error:

Error code: 400 - {‘error’: {‘message’: ‘background cannot be used with MCP tools’, ‘type’: ‘invalid_request_error’, ‘param’: ‘background’, ‘code’: ‘unsupported_parameter’}}

This looks like potentially a bug to me as the official documentation suggests this should be possible!

Thank you!

5 Likes
2

I am also having this issue - would be extremely interested in a fix.

2 Likes
3

Indeed. Deep research is very prone to billable timeouts, so background mode with MCP is a must-have.

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:man_raising_hand::man_facepalming:
wowza, this is a pain… same issues

5

Hey everyone! Hannah from the User Ops team here. Thanks for sharing this feedback with us. Wanted to let you know that Deep Research is now compatible with the File Search tool in the Responses API, and we’ve made background mode available for MCP and File Search. Deep Research queries are also more efficient (cheaper!) now due to some improved token counting.

Let us know how you get on!

3 Likes
6

I can confirm this works for me now!! Also seeing dramatically cheaper requests (from previously around $15 per request to now under $2!)

1 Like