Price a model call before running it, without running it.

Bearer token authentication. Normally a Firebase or Cloud JWT. A 'comfyui-' prefixed API key is also accepted in this header: the prefix classifies the value as an API key and it is validated exactly as if it had been sent in X-API-Key. Accepted on the operations served by the comfyFirebase auth middleware (BE-9720, parity with ingest).

Lowercase provider segment of the canonical {provider}/{model} model ID - the partner whose model is being run. The schema is RouterProviderSegment, the SAME component a catalog entry's provider field references, so an ID GET /v2/models lists cannot drift from the ids this route accepts. Its pattern is a CONTRACT statement, not enforcement: comfy-api installs no OpenAPI request validator and oapi-codegen binds path parameters as plain strings, so the handler must re-validate this segment itself before using it to select a provider or compose an upstream URL. Lowercase provider segment of the canonical {provider}/{model} model ID - the partner whose model is being addressed. The invocation route's provider path parameter and a catalog entry's provider field both reference this one schema, which is what keeps the listed IDs and the accepted IDs from drifting apart. The pattern is a CONTRACT statement, not enforcement: comfy-api installs no OpenAPI request validator and oapi-codegen binds path parameters as plain strings, so a handler must re-validate the segment itself before using it to select a provider or compose an upstream URL. The alphabet deliberately admits no /, no percent-encoding, and no repeated separator, so no accepted value can contain a . or .. path segment.

Lowercase model segment of the canonical {provider}/{model} model ID - the model to run within that provider. As with provider, the schema is the shared RouterModelSegment component and its pattern documents the contract rather than enforcing it - see RouterProvider. Lowercase model segment of the canonical {provider}/{model} model ID - the model to run within that provider. Shared by the invocation route's model path parameter and a catalog entry's model field, for the same no-drift reason as RouterProviderSegment. As with the provider segment, the pattern documents the contract and does not enforce it. Dots are permitted inside the segment because partner model IDs use them for versions (flux-pro-1.1), but a repeated separator is not, so .. cannot appear.

Selects an alternate provider to serve this model, instead of its current default. Omitting it runs native dispatch on the model's own default provider; default, comfy, and comfyui are aliases for that same native behavior and name no override, because Comfy Router is never itself a serving backend. The alternate providers Router can retarget a model onto are fal, wavespeed, runware, and higgsfield; which of them a given model supports is reported by GET /v2/models/{provider}/{model}. When an alternate provider is selected, the native request body is translated into that provider's real schema unless strict_mode=true; see strict_mode and fallback_provider. Its refusals are checked in a fixed order, and an earlier one answers whether or not a later one would. A value that is not a registered provider at all is refused 400 with error_type: invalid_input. Then a request whose body selects a multipart operation (an edit - for example gpt-image's image field) is refused 409, also with error_type: invalid_input, whose detail begins "this request's image selects the edit operation" - but only when the named provider's translator for this model cannot itself serve that operation; a leg whose translator does carry the media is not refused and proceeds normally, so this is a per-leg refusal rather than a blanket one. Then a request that has already resolved a bring-your-own-key credential for the provider in the path is refused 409, also with error_type: invalid_input, whose detail begins this request resolved a BYOK credential - see the 409 on this route, where that detail is the only thing separating this case, and the multipart case above, from the Idempotency-Key one. That BYOK check runs whether or not the named provider has a leg for this model. Then the named provider's own gate refuses 403 with error_type: not_enabled when that provider is not turned on for you, and 503 with error_type: service_unavailable when the gate cannot be evaluated - a flag-evaluation failure, or a missing or nil gate entry. Only past all of those is a real provider that does not serve this model refused 400 with error_type: invalid_input, the same answer as a value that is not a registered provider at all - both mean the model_provider value cannot serve this model, and that 400's detail is human-readable and not a contract, so read GET /v2/models/{provider}/{model} to learn which providers a model does support rather than parsing it; past that 400, this workspace's partner-provider policy for the named vendor is evaluated too and can refuse 403 or 503 of its own. Neither this parameter nor fallback_provider is available on a BYOK request, and the two are unavailable in different ways: the credential was resolved for the provider named in the path while every alternate leg dispatches on Comfy's own key, so an explicit model_provider is refused with that 409, and fallback_provider is inert rather than refused - no retry against an alternate provider is attempted and the first attempt's own failure is what the caller receives. The same split applies to a multipart body: only an explicit model_provider reaches the 409 above, and only for a leg whose translator cannot serve the operation, while the automatic on-failure retry fallback_provider controls is simply skipped (inert, not refused) for any multipart body. Router defines no provider_not_available or validation_error error_type: these conditions fold onto invalid_input. The error_type set can still grow, so treat any value you do not recognize as internal_error rather than switching exhaustively.