PR #24314: fix(core): add strip_null_bytes() to safe_dumps — prevents PostgreSQL 22P05 errors in spend logs

• Repository: BerriAI/litellm
• Author: xykong
• State: open | merged: False
• Link: https://github.com/BerriAI/litellm/pull/24314

Description (problem / solution / changelog)

Summary

Fixes PostgreSQL 22P05: invalid byte sequence for encoding "UTF8": 0x00 errors that occur when LLM request/response payloads containing null bytes are written to spend log tables.

Fixes #24310
Related: #21290, #15519

Problem

Null bytes (\x00 / \^@) can appear in LLM payloads — e.g., from multimodal requests, tool call responses, or certain model outputs. When these reach PostgreSQL text columns via json.dumps(), the DB rejects them with:

ERROR:  invalid byte sequence for encoding "UTF8": 0x00
SQLSTATE: 22P05

Changes

litellm/litellm_core_utils/safe_json_dumps.py

Add strip_null_bytes() helper and integrate null byte removal into safe_dumps() at the string serialization level:

def strip_null_bytes(data: Any) -> Any:
    """Recursively remove \x00 null bytes from strings to prevent PostgreSQL 22P05 errors."""
    if isinstance(data, str):
        return data.replace("\x00", "")
    if isinstance(data, dict):
        return {k: strip_null_bytes(v) for k, v in data.items()}
    if isinstance(data, list):
        return [strip_null_bytes(item) for item in data]
    ...

Inside _serialize():

- if isinstance(obj, (str, int, float, bool, type(None))):
-     return obj
+ if isinstance(obj, str):
+     return obj.replace("\x00", "")   # strip null bytes inline
+ if isinstance(obj, (int, float, bool, type(None))):
+     return obj
  ...
  try:
-     return str(obj)
+     return str(obj).replace("\x00", "")  # also strip fallback str()

litellm/proxy/spend_tracking/spend_tracking_utils.py

Replace ad-hoc json.dumps() with safe_dumps() in two call sites:

- return json.dumps(messages, default=str)
+ return safe_dumps(messages)

- _request_body_json_str = json.dumps(_request_body, default=str)
+ _request_body_json_str = safe_dumps(_request_body)

Also add early null byte stripping in _sanitize_request_body_for_spend_logs_payload string handling:

  elif isinstance(value, str):
+     value = strip_null_bytes(value)
      if len(value) > max_string_length_prompt_in_db:

Why centralize in safe_dumps vs. caller level

The current codebase has ad-hoc _strip_null_bytes() in proxy/utils.py for some paths, but safe_dumps() is the shared serialization utility. Centralizing here means any future caller of safe_dumps() is automatically protected without remembering to strip separately.

Testing

The existing safe_json_dumps test suite covers the serialization path. New behavior:

• Strings with \x00 pass through safe_dumps() with null bytes removed
• All spend log serialization paths (messages, request_body) now use safe_dumps()

Impact

• Minimal scope: 2 files, ~25 lines
• No breaking changes: safe_dumps() signature unchanged; output may differ only when input contains \x00
• Backward compatible: strip_null_bytes() exported as public function for reuse

Changed files

• litellm/litellm_core_utils/safe_json_dumps.py (modified, +20/-2)
• litellm/proxy/spend_tracking/spend_tracking_utils.py (modified, +4/-3)