[CRITICAL] Three LiteLLM bugs blocking Claude models: 4.6 prefill error, tool calling config error (4.5), and large output interruptions

[vluciany]

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[CRITICAL] LiteLLM tool calling error with claude-sonnet-4-5: Missing tools= parameter causes complete session failure

Environment

• Qodo Command Version: [Run qodo --version and paste here]
• Model: anthropic/claude-sonnet-4-5
• Platform: Linux
• Installation Method: [npm/pip/other]

Description

Qodo Command completely fails to start sessions with claude-sonnet-4-5 due to a LiteLLM configuration error. The system attempts to use tool calling mode but does not pass the required tools= parameter to the Anthropic API.

Error Message

Error: Model error (BadRequest): litellm.BadRequestError: OpenAIException - 
litellm.UnsupportedParamsError: Anthropic doesn't support tool calling without 
`tools=` param specified. Pass `tools=` param OR set `litellm.modify_params = True` 
// `litellm_settings::modify_params: True` to add dummy tool to the request.

Received Model Group=anthropic/claude-sonnet-4-5
Available Model Group Fallbacks=None. 
Received Model Group=claude-sonnet-4-5
Available Model Group Fallbacks=None 
LiteLLM Retried: 2 times, LiteLLM Max Retries: 3

Impact

• Severity: CRITICAL
• Effect: Complete inability to use AI assistant
• Workaround: Must switch to different model (GPT-4, claude-3-7-sonnet)

Root Cause Analysis

Qodo Command's LiteLLM integration is calling the Anthropic API in tool-calling mode but failing to provide either:

1. The required tools= parameter with tool definitions, OR
2. The litellm.modify_params = True configuration setting

This suggests a configuration mismatch between Qodo Command's tool registration system and the LiteLLM proxy layer.

Steps to Reproduce

1. Install Qodo Command (latest version)
2. Launch with claude-sonnet-4-5: qodo --model claude-sonnet-4-5
3. Attempt any interaction
4. Session immediately fails with the error above

Expected Behavior

Qodo Command should either:

• Pass the tools= parameter with registered tool definitions to LiteLLM
• Configure litellm.modify_params = True to auto-add dummy tools
• Properly initialize the tool calling system before making API calls

Additional Context

This is part of a larger pattern of issues with Claude models in Qodo Command:

Related Issues:

1. BUG A: claude-sonnet-4-6 crashes on every turn due to prefill removal (requires LiteLLM PR #21464)
2. BUG B: Large output interruptions affecting all models (output size limits)
3. BUG C: This tool calling configuration error (NEW)

Evidence:

• 24 documented log entries in attached database
• Multiple session failures across different Claude models
• Pattern suggests LiteLLM version/configuration issues

Suggested Fix

1. Update LiteLLM to latest version (includes PR #21464 for prefill fix)
2. Add proper tool calling configuration:

   # In Qodo Command LiteLLM setup
   litellm.modify_params = True
   # OR
   # Pass tools parameter explicitly when calling Anthropic API

3. Ensure tool definitions are properly registered before API calls

Workarounds (Temporary)

Users can work around this by:

# Use OpenAI models
qodo --model gpt-4

# Or use older Claude models
qodo --model claude-3-7-sonnet

# Try environment variable (may not work)
export LITELLM_MODIFY_PARAMS=True
qodo --model claude-sonnet-4-5

Files Available

• Complete bug analysis database: qodo_session.db (24 entries)
• Detailed bug report: BUG_REPORT_CRITICAL.md
• Session logs showing failure pattern

Priority

URGENT - This completely blocks users from using claude-sonnet-4-5, which is one of the primary models for Qodo Command.

Request

Please prioritize:

1. LiteLLM update to latest version
2. Tool calling configuration fix
3. Better error handling for LiteLLM configuration issues

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Reported by: [Your GitHub username]
Date: 2026-02-19
Session Database: Available upon request

[vluciany]

BUG_REPORT_CRITICAL.md
could not add qodo_session.db, but could email it, on request.

[HenryXiaoYang]

same issue

[HenryXiaoYang]

litellm is serverside, we cannot do anything about it