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Two policies shape the request itself before it is forwarded. Both run at pre_request and are scoped like any other policy.

`model_allowlist`

Restrict which models a consumer or gateway may call, matching by name with glob patterns. This is the policy-based complement to a consumer’s model_policies — use it for a gateway-wide default.

Setting	Type	Default	Notes
`allowed_models`	string[]	—	Name patterns permitted, `` wildcard (e.g. `gpt-5`). Required.
`behavior_on_disallowed`	enum	`reject`	`reject` (403) or `substitute`.
`substitute_with`	string	—	Model written back when `substitute` (must match the allowlist).
`default_model`	string	—	Model injected when the request omits one (must match the allowlist).

{
  "slug": "model_allowlist",
  "settings": {
    "allowed_models": ["gpt-4o", "gpt-4o-mini"],
    "behavior_on_disallowed": "substitute",
    "substitute_with": "gpt-4o-mini"
  }
}

`prompt_template`

Inject and version prompts server-side, so system instructions live in the gateway rather than in every client. It supports two modes, which can be combined:

Mode A — inject templates: render operator-defined system prompts from context variables (headers or JWT claims) and inject them into the request.
Mode B — named templates: maintain named, versioned templates that clients reference by {template://name@label}, with required-variable validation.

Setting	Type	Default	Notes
`template_engine`	enum	`mustache`	Rendering engine (`mustache` in v1).
`context_variables`	map	—	Named values resolved from `header` or `jwt_claim` sources.
`inject_templates`	array	—	Mode A: `[{ id, content, position, on_existing_system }]`.
`named_templates`	array	—	Mode B: named templates with `versions[]` (each `{ version, labels, content, required_variables }`).
`allow_untemplated_requests`	bool	`true`	When false + named templates set, reject requests with no template reference.
`on_missing_context_variable`	enum	`error`	`error`, `empty_string`, or `skip_injection`.
`default_label`	string	—	Label used when a reference omits `@label`.

{
  "slug": "prompt_template",
  "settings": {
    "context_variables": {
      "tenant": { "source": "header", "name": "X-Tenant-Id" }
    },
    "inject_templates": [
      { "id": "base", "content": "You are the assistant for {{tenant}}.", "on_existing_system": "merge" }
    ]
  }
}

Injected content is placed in the system role; on_existing_system chooses whether to merge with or replace an existing system prompt.

​model_allowlist

​prompt_template

`model_allowlist`

`prompt_template`