fix(http_handler): bypass cache when shared_session is provided for aiohttp tracing

[shin-bot-litellm]

Description

Fixes #20174 - aiohttp client tracing logs not visible when using LiteLLM.

Problem

When users pass a shared_session with trace_configs to acompletion(), the get_async_httpx_client() function was ignoring the user's session and returning a cached client. This meant the user's tracing configuration was never used, so aiohttp tracing logs were never emitted.

Root Cause

In get_async_httpx_client():

_cached_client = cache.get_cache(_cache_key_name)
if _cached_client:
    return _cached_client  # <-- User's shared_session is completely ignored!

The cache lookup happened before checking if shared_session was provided, so any cached client for that provider was returned, ignoring the user's custom session configuration.

Solution

When shared_session is provided, bypass the cache entirely and create a new handler that uses the user's session directly. This preserves the user's ClientSession configuration including:

• trace_configs (for aiohttp tracing)
• Custom connector settings
• Any other session-level configuration

Test Plan

• Added test_shared_session_bypasses_cache - verifies cache is bypassed when shared_session is provided
• Added test_shared_session_each_call_gets_new_handler - verifies each call with a different shared_session gets its own handler
• All existing tests continue to pass (34 tests in test_http_handler.py)

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Project	Deployment	Actions	Updated (UTC)
litellm	Ready	Preview, Comment	Feb 7, 2026 4:14am

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[greptile-apps]

Greptile Overview

Greptile Summary

Fixed aiohttp client tracing by bypassing cache when user provides a shared_session. The fix adds an early-return path in get_async_httpx_client() that creates a new handler when shared_session is provided, ensuring the user's ClientSession configuration (including trace_configs) is preserved rather than being ignored by the cache lookup.

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The fix is well-targeted, addressing a specific bug where cached clients were preventing user-provided sessions from being used. The change adds an early-return path that bypasses caching when shared_session is provided, which is the correct approach. Tests comprehensively verify the new behavior, and the logic is straightforward with clear documentation.
• No files require special attention

Important Files Changed

Filename	Overview
litellm/llms/custom_httpx/http_handler.py	Added early-return logic to bypass cache when shared_session is provided, preserving user's session configuration for aiohttp tracing
tests/test_litellm/llms/custom_httpx/test_http_handler.py	Added comprehensive tests to verify cache bypass behavior when shared_session is provided

Sequence Diagram

sequenceDiagram
    participant User
    participant acompletion
    participant get_async_httpx_client
    participant Cache
    participant AsyncHTTPHandler

    Note over User: User provides shared_session<br/>with trace_configs

    User->>acompletion: acompletion(shared_session=session)
    acompletion->>get_async_httpx_client: get_async_httpx_client(llm_provider, shared_session)
    
    alt shared_session is provided
        Note over get_async_httpx_client: NEW: Bypass cache logic
        get_async_httpx_client->>AsyncHTTPHandler: Create new handler with shared_session
        AsyncHTTPHandler-->>get_async_httpx_client: Return new handler
        get_async_httpx_client-->>acompletion: Return handler with user's session
        Note over acompletion: User's trace_configs are preserved
    else shared_session is None
        get_async_httpx_client->>Cache: Check cache for existing client
        alt Cache hit
            Cache-->>get_async_httpx_client: Return cached client
        else Cache miss
            get_async_httpx_client->>AsyncHTTPHandler: Create new handler
            AsyncHTTPHandler-->>get_async_httpx_client: Return new handler
            get_async_httpx_client->>Cache: Store in cache
        end
        get_async_httpx_client-->>acompletion: Return handler
    end

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[greptile-apps]

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