Field: alias reserved tool names

What it does

Some upstreams reserve function names for hosted tools. xAI Grok reserves view_image for Image Understanding. Codex also ships a client-side function named view_image. If Monoize forwards that function unchanged, the model treats it as the hosted tool, never returns a client function_call, and the Codex turn ends after reasoning.

This transform rewrites matching function and custom tool names on the request, including history ToolCall nodes and tool_choice, then restores the original names on the response so the client still sees view_image.

Native descriptors such as type = "web_search" are not renamed.

Reference

When to use

• The Provider is Grok / xAI / a Responses adapter such as CPA, and Codex view_image never appears as a function call.
• Add two rules with the same config: one request rule and one response rule.

Configuration

Example rule

{
  "transform": "field_alias_reserved_tool_names",
  "enabled": true,
  "phase": "request",
  "models": ["grok-*"],
  "config": {}
}

Use the same config with "phase": "response" so aliases are mapped back before Codex receives the stream.