What changed

ChangedProject keys read prices in their own audience (price contract 2)

Release candidate; deployment and consumer acceptance are pending. This fixes resale customers' project keys exposing the billing company's wholesale rates and charges. /v1/models, receipts, stream-start receipts, idempotent replays and MCP carry pricingContract 2 (pricing_contract on the listing), priceAudience and priceBasis. A resale key sees retail amounts (priceBasis retail), or no amount fields at all (priceBasis withheld) when accepted client-issued retail terms do not cover the request. A direct customer's key sees the platform charge it pays (priceBasis direct). Wholesale remains available through client and operator access. The affected price fields are a breaking change; the release decision and applicable notice must be recorded before publication.

API versioningFirst call

AddedUse Modelvia from an agent host over MCP

An MCP server exposes the project-key tools models_list, request_receipt and chat_completion, and the gateway serves POST /mcp as stateless JSON-RPC over Streamable HTTP. Configuration for the common agent hosts is published on /docs/mcp.

Agent host guide

AddedA client can provision its own customers, projects and keys

A client integration key can create customer accounts, projects and project keys under /v1/client without an operator in the loop. The account boundary is unchanged: a client only ever sees its own customers.

Integration guide

AddedAnthropic Messages API on the same key and price

POST /v1/messages speaks the Anthropic Messages API, including the streaming event sequence and x-api-key authentication, scoped to the key-serving routes only. It is the same service, the same key, the same price and the same receipt as the OpenAI-shaped surface.

Your first call

AddedA client chooses where its own customers pay

Each client account carries a customer-checkout setting — in the client's own application, in the Modelvia portal, both, or off — so a reseller decides where its customers see a payment page. Collection stays switched off until it is authorised for that account.

ChangedThe model listing carries what an agent framework checks before it starts

GET /v1/models publishes context_length, max_output_tokens and the accepted price for every route. OpenAI generation parameters are forwarded where they are honoured and refused by name where they are not, and reasoning_effort maps onto the fast, medium and smart routing profiles.

Parameters and refusals