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CodeTracked since May 19, 2026

Skip unsupported extra_body on Azure-hosted DeepSeek v4 requests

DeepSeek-Reasonix now detects Azure-hosted endpoints (`azure.com` in `baseUrl`) and removes the proprietary `extra_body.thinking` field from outgoing requests for those endpoints while still sending `reasoning_effort`, preventing the `Unrecognized request argument supplied: extra_body` 400 error on DeepSeek v4 calls.

DeepSeek-ReasonixDeepSeek v4Azure Foundry endpointextra_body

What Happened

  • DeepSeek-Reasonix now detects Azure-hosted endpoints (`azure.com` in `baseUrl`) and removes the proprietary `extra_body.thinking` field from outgoing requests for those endpoints while still sending `reasoning_effort`, preventing the `Unrecognized request argument supplied: extra_body` 400 error on DeepSeek v4 calls.
  • DeepSeek-Reasonix now detects Azure-hosted endpoints (`azure.com` in `baseUrl`) and removes the proprietary `extra_body.thinking` field from outgoing requests for those endpoints while still sending `reasoning_effort`, preventing the `Unrecognized request argument supplied: extra_body` 400 error on DeepSeek v4 calls.
  • 1 evidence item attached for review.

What is Different

Before

Scattered source updates, isolated context, and manual follow-up across multiple feeds.

Now

Introduced `_isAzureEndpoint()` and a payload gate in `buildPayload()` to conditionally strip `extra_body` for Azure hosts, and added a regression test for Azure `baseUrl` behavior so the compatibility change is preserved.

Why Track This

Why It Matters

Users and operators calling Azure-hosted DeepSeek v4 models through this client should stop seeing failed reasoning requests due to a 400 validation error, so inference calls are more reliable without manual retries or request workarounds. Technically, this is a provider-compatibility fix that aligns Azure payloads with supported fields by removing `extra_body.thinking` while retaining `reasoning_effort`; monitor for additional Azure endpoint URL patterns that could bypass hostname detection and reintroduce unsupported-field failures.

Impact

Users and operators calling Azure-hosted DeepSeek v4 models through this client should stop seeing failed reasoning requests due to a 400 validation error, so inference calls are more reliable without manual retries or request workarounds. Technically, this is a provider-compatibility fix that aligns Azure payloads with supported fields by removing `extra_body.thinking` while retaining `reasoning_effort`; monitor for additional Azure endpoint URL patterns that could bypass hostname detection and reintroduce unsupported-field failures.

What To Watch Next

  • Watch whether DeepSeek-Reasonix becomes a repeated pattern.
  • Track follow-up changes around LLMOps.
  • Compare future signals against this evidence trail.
  • Re-check risk flags: azure_host_detection_false_positive_or_negative, azure_endpoint_url_pattern_changes.
Open Topic TimelineOpen Technical EventOpen Original Sourceazure_host_detection_false_positive_or_negative / azure_endpoint_url_pattern_changes / silent_payload_drift_on_azure_api_updates

Supporting Evidence

GITHUB PULL REQUESTHigh Trust

esengine/DeepSeek-Reasonix PR #1316: fix(client): skip extra_body for Azure endpoints (#1299)

Azure DeepSeek v4 requests now bypass `extra_body` payload fields and keep `reasoning_effort` to match Azure API expectations.