[Bug] azure-openai does not recover invalid_encrypted_content after a provider switch #5583

Client or integration

Codex App

Area

Provider adapter

Summary

Switching an existing Responses thread to an azure-openai provider can return invalid_encrypted_content. The thread contains a reasoning item encrypted by the previous provider, and Azure cannot verify it.

OpenCodex already has one-shot opaque-blob recovery for this exact error shape. However, both recovery gates require adapterName === "openai-responses". The Azure adapter wraps the same Responses passthrough contract but reports adapterName === "azure-openai", so recovery never runs.

I expected OpenCodex to remove the foreign reasoning state and retry once, matching the behavior added for OpenAI in #2269.

Reproduction

1. Configure a key-auth provider with adapter: "azure-openai" and a Responses-capable Azure model.
2. Start a thread on another Responses provider, then switch the same thread to the Azure model.
3. The next request may replay the previous provider's reasoning encrypted_content.
4. Azure returns 400 invalid_encrypted_content.

The failure is also deterministic with a direct request containing an undecryptable reasoning item:

curl -sS http://127.0.0.1:10100/v1/responses \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "azure-test/gpt-5.6-sol",
    "input": [
      {
        "type": "reasoning",
        "id": "rs_probe",
        "summary": [],
        "encrypted_content": "gAAAAABprobe"
      },
      {
        "type": "message",
        "role": "user",
        "content": [{"type": "input_text", "text": "Reply with exactly OK."}]
      }
    ],
    "reasoning": {"effort": "high"},
    "max_output_tokens": 64,
    "stream": false
  }'

Current result: one upstream request and the Azure 400 reaches the client.

I validated a local fix in two parts:

1. Allow azure-openai in both adapter gates in src/server/responses/core-opaque-recovery.ts.
2. When _stripReasoningEncryptedContent is set for an Azure destination, drop the stale reasoning input item. Removing only encrypted_content leaves the foreign id and Azure then returns Item with id 'rs_probe' not found.

With both changes, the same request performs one recovery retry and completes with 200.

Version

2.61.0

Operating system

macOS 26.0.1 (25A362)

Provider and model

Custom azure-openai provider / gpt-5.6-sol

Logs or error output

{
  "error": {
    "message": "The encrypted content gAAA... could not be verified. Reason: Encrypted content could not be decrypted or parsed.",
    "type": "invalid_request_error",
    "param": null,
    "code": "invalid_encrypted_content"
  }
}

Screenshots and supporting files

Related but not Azure-specific: #2247, #2248, #2251, and merged fix #2269.

Current dev still limits opaque-blob recovery to openai-responses in core-opaque-recovery.ts.

Redacted configuration

{
  "providers": {
    "azure-test": {
      "adapter": "azure-openai",
      "baseUrl": "https://<redacted>/openai/v1",
      "authMode": "key",
      "apiKey": "${AZURE_API_KEY}",
      "models": ["gpt-5.6-sol"]
    }
  }
}

Checks

• I searched existing issues and documentation.
• I removed secrets, tokens, account details, request credentials, and personal data.