API.market vs Optio: Which Is Better in 2026?

API.market is an API marketplace for developers and teams building software, automations and AI-agent workflows. It provides a place to discover APIs and use their capabilities, with a hosted Model Context Protocol gateway for agents that support remote MCP connections. The company is registered in the United States, is based in San Francisco and launched in April 2024.

For an agent workflow, the connection endpoint is https://api.market/api/mcp/gateway. Setup documentation is available at https://api.market/mcp. The gateway uses Streamable HTTP and requires an account with OAuth or API-key authentication. It is a hosted proprietary service; it is not offered as a public open-source server implementation. The website and the MCP connection endpoint serve different purposes: clients should connect to the gateway URL, while people can use the setup page to learn how to configure access.

The gateway exposes five tools. search_apis helps find relevant APIs in the catalog. get_api_tools provides information about the operations associated with a selected API. call_api invokes an operation. check_usage helps inspect usage, and manage_subscription handles subscription-related actions. This gives an agent a discovery-and-execution workflow without presenting every catalog operation as a separate tool at connection time.

A typical use starts with a developer defining the capability their application or agent needs. The agent can search for an API, inspect the available operations and required inputs, and then make an authenticated call where access is available. Developers should review the selected provider, its data requirements and its pricing before placing calls in a production workflow. Requests may send task data to the chosen API provider. Subscription changes and calls to paid operations should remain subject to the application owner’s approval and spending controls.

Pricing depends on the selected API. Free tiers and paid plans vary across providers; the marketplace should not be interpreted as unlimited free access to every API. API.market is relevant to developers and teams that want API discovery, access and usage information in a shared workflow, including teams connecting AI agents to external services. Product questions can be sent to hey@api.market.

Optio is a developer API that returns decisions you can build on. Send a question and a set of options and get back a choice, a score, or a yes/no answer together with calibrated probabilities, so your application knows not just what the model picked but how confident it is. The API is a drop-in /v1/systemone endpoint that you can call from any language with a simple HTTP request. A free playground on the website lets you try the decision model in the browser before writing any code. There is no waitlist: sign up, get credits and start calling the API right away, then pay as you go with credits when you scale. Optio is built for developers, startups and product teams who want to add decision-making, ranking, triage or approval logic to their apps without training and hosting their own models.

What problem it solves

Developers who need reliable yes/no, choice and scoring decisions with probabilities they can trust, without building their own model.