AI Gateway AWS Bedrock fails with 400 error tools.0.custom.eager_input_streaming

AI SDK
,
1

Problem

Hi team, I am encountering a schema validation error when making tool-calling requests via the HTTP interface using the AI Gateway. The issue specifically happens when routing the request to AWS Bedrock.

Important Context (Recent Regression):
This exact implementation was working perfectly fine yesterday (April 16, 2026). The error just started occurring today (April 17, 2026) without any changes to my request payload. This strongly suggests that a recent update or deployment to the AI Gateway introduced this breaking change.

Error Message

{
  "error": "tools.0.custom.eager_input_streaming: Extra inputs are not permitted",
  "statusCode": 400
}

Steps to Reproduce

I am calling the HTTP interface directly.
When I set the providerOptions to route only to Bedrock, the request fails with the error above:

providerOptions: {
  gateway: {
    only: ['bedrock'] // ❌ Fails with 400 Extra inputs are not permitted (Since April 17)
  }
}

However, if I change the routing to only Anthropic, the exact same request payload works perfectly fine:

providerOptions: {
  gateway: {
    only: ['anthropic'] // ✅ Works successfully
  }
}

It appears a recent update to the AI Gateway / AI SDK automatically injects a custom: { eager_input_streaming: ... } metadata field into the tools definition.