[Bug]: LiteLLM v1.77.2 — store_prompts_in_spend_logs=true does not store messages/response in DB (always {})

[lisyoen]

What happened?

We found a reproducible issue in LiteLLM v1.77.2 where the store_prompts_in_spend_logs feature completely fails.
Even when store_prompts_in_spend_logs: true is enabled, all rows in the LiteLLM_SpendLogs table have empty JSON objects {} in both messages and response columns.

Other fields such as request_id, tokens_in/out, total_cost, and status are stored correctly, and API responses are successfully returned to the client.
This means the message and response payloads are being lost somewhere in the internal spend-log write pipeline.

We tested with:

• Docker image: ghcr.io/berriai/litellm:v1.77.2
• PostgreSQL backend
• No custom callbacks or guardrails (pure default setup)
• stream: false (non-streaming requests)
• Verified with direct SQL query:

  SELECT messages, response
  FROM "LiteLLM_SpendLogs"
  ORDER BY "startTime" DESC
  LIMIT 5;
  
  

Relevant log output

litellm  | 16:58:50 - LiteLLM Proxy:DEBUG: litellm_pre_call_utils.py:825 - receiving data: {'model': 'Qwen/Qwen3-4B-Instruct-2507', 'messages': [{'role': 'user', 'content': 'DEBUG: store_prompts_in_spend_logs 동작 추적'}], 'stream': False, 'user': 'debug-trace'}
litellm  | 16:58:56 - LiteLLM Proxy:DEBUG: utils.py:3277 - Spend Logs transactions: 0
litellm  | INFO: Writing spend log to db
litellm  | INFO: Logged request status: success

Database query result:
SELECT messages, response FROM "LiteLLM_SpendLogs" ORDER BY "startTime" DESC LIMIT 1;
 messages | response 
----------+----------
 {}       | {}

Are you a ML Ops Team?

No

What LiteLLM version are you on ?

v1.77.2 (tested both standard and -stable variants)

Twitter / LinkedIn details

No social details to share publicly.

[ishaan-jaff]

@mubashir1osmani can you repro this? it works for our team

[HFL-EDEKA]

I'm experiencing the same issue - even with the new release v1.80.5-stable.
To reproduce:

• in DB table "LiteLLM_Config", I have this record:
  param_name = general_settings
  param_value = {"store_model_in_db": true, "store_prompts_in_spend_logs": true}
• restarted the server
• still just {} in columns "messages" and "response" in DB table "LiteLLM_SpendLogs"
  :-(

[webysther]

Will be nice that store_prompts_in_spend_logs can be set as env var like STORE_MODEL_IN_DB

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.

[BiAndNerdy]

I have this issue as well.

[github-actions]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs.