openai_responses_model_rewrite

Rewrites the model field in Responses and Chat Completions request bodies.

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Rewrites the model field in Responses and Chat Completions request bodies.

Configuration Notes

With openai_agentic_loop, place this filter before openai_responses_validate. The rewrite reserves its parsed input and configured model expansion against the request’s retained-payload limit before either allocation.

Quote wildcard alias keys in YAML, such as "gpt-4.1-*", so * is parsed as a literal character rather than YAML alias syntax. The examples quote all alias keys for consistency.

One alias table serves both create endpoints: the filter rewrites POST /v1/responses and POST /v1/chat/completions request bodies and leaves every other path untouched. The filter name keeps its openai_responses_ prefix for config compatibility.

Configuration

Field	Type	Required	Description
`default_model`	string	no	Model name to inject when the request body has no `model` field or when the field is `null`.
`headers`	ModelRewriteHeaders	no	Header names for promoted model values. `effective_model` and `original_model` must use distinct names.
`headers.effective_model`	string	no	Header name for the effective (post-rewrite) model value. Must not be a hop-by-hop, framing, Host, credential, API-key, or other internal `x-praxis-*` header. Dedicated default `x-praxis-ai-effective-model` remains allowed. Must differ from `original_model`.
`headers.original_model`	string	no	Header name for the original (pre-rewrite) model value. Must not be a hop-by-hop, framing, Host, credential, API-key, or other internal `x-praxis-*` header. Dedicated default `x-praxis-ai-original-model` remains allowed. Must differ from `effective_model`.
`model_aliases`	object<string, string>	no	Map from client-facing model names or single-wildcard patterns to backend model names. Quote wildcard keys in YAML. Exact aliases win before wildcard aliases; wildcard aliases are matched by literal specificity.
`on_invalid`	`continue` \| `reject`	no	Behavior when the body is not valid JSON.

Examples

Example 1

filter: openai_responses_model_rewrite
default_model: "llama-3.3-70b"
model_aliases:
  "codex-mini-latest": "llama-3.3-70b"
  "gpt-4.1-*": "qwen-2.5-72b"
  "gpt-4.1-mini": "qwen-2.5-72b"

Example 2

filter: openai_responses_model_rewrite
default_model: "llama-3.3-70b"
model_aliases:
  "codex-mini-latest": "llama-3.3-70b"
  "gpt-4.1-*": "qwen-2.5-72b"
on_invalid: continue
headers:
  effective_model: x-praxis-ai-effective-model
  original_model: x-praxis-ai-original-model