OpenAPI Studio

OpenAPI Studio is a visual editor for designing, testing, and publishing AI-ready APIs. Its flow builder shows API paths as a node graph with four layout algorithms, and a server-side proxy runs requests without browser CORS limitations. Recipes chain up to 10 API calls, map responses with JSONPath, and apply assertions at each step. Each workspace includes a six-tool MCP server for searching, retrieving, creating, updating, running, and analyzing. The service supports OpenAPI and AsyncAPI, contract validation, Git synchronization, and team collaboration. WebSocket endpoints can be modeled and tested alongside HTTP, then exported as AsyncAPI 3.0 YAML. Integrations include GitHub, Slack, Linear, Notion, and MCP connections for AI assistants; supported integrations use OAuth and encrypted workspace token storage. Workspaces provide Owner, Editor, and Viewer roles. Cloud data is stored on Cloudflare D1, KV, and R2; self-hosted deployments use the customer's Cloudflare account. A free plan is available, with paid plans from $9/mo. SSO, SCIM, and audit logs are not offered.

OpenAPI Studio combines visual API flows, request execution, recipes, and workspace tools. Its free plan has limited workspaces and integrations, while paid plans add capacity and features.

It suits people designing and testing APIs visually, including teams that want recipe-based API calls or MCP connections. Workspaces can be self-hosted or used on the web.

OpenAPI Studio is a visual environment for designing, testing, and publishing APIs, including HTTP and WebSocket services. It fits developers and small teams that want API workflows and MCP access in one workspace, with self-hosting as an option. The main trade-off is that enterprise identity controls are absent and the most generous collaboration, integration, and request allowances require higher tiers.

Overview

The flow builder turns API paths into a node graph and offers four layout algorithms, so complex contracts can be arranged in ways that remain readable. A server-side proxy executes requests without browser CORS restrictions, allowing design and endpoint checks to happen together. OpenAPI Studio supports OpenAPI, AsyncAPI, contract validation, and Git synchronization, making it suitable for teams that need both specification work and an execution loop.

Recipes chain up to 10 API calls, map responses with JSONPath, and apply assertions at each step. That is a practical way to codify multi-request checks, although teams using AI assistants heavily must watch the daily MCP quotas on lower plans.

Key features

Workflow, protocols, and MCP

Every workspace includes a six-tool MCP server for searching, retrieving, creating, updating, running, and analyzing APIs. WebSocket endpoints can be modeled and tested beside HTTP endpoints, then exported as AsyncAPI 3.0 YAML. This combination is more useful than an HTTP-only editor for event-driven projects.

Integrations and security

Native connections cover GitHub, Slack, Linear, Notion, and MCP-compatible AI assistants. OAuth is used for supported integrations, with tokens encrypted in the workspace rather than requiring raw API keys. Workspaces include Owner, Editor, and Viewer roles with enforced permissions. SSO, SCIM, and audit logs are not offered, so organizations with formal identity provisioning or compliance reporting requirements should look elsewhere.

The service says it does not sell data, run client-side analytics, or use tracking pixels, and it supports exporting or deleting data. Cloud storage uses Cloudflare D1, KV, and R2; self-hosted deployments use the customer's Cloudflare account. Community support runs through GitHub Issues on every tier, while priority email support starts with Pro.

Pricing

Free — free, billed forever. One workspace, three members, seven-day execution history, public hotlinks, one MCP token per spec, and 500 MCP requests per day are enough for personal projects or evaluation. GitHub and integrations are unavailable, and public links may not suit private APIs.

Pro — $9 a month, billed monthly. Three workspaces, three members, 30-day history, private hotlinks, a credential vault, three MCP tokens per spec, and 2,000 daily MCP requests make this the practical individual or small-project tier. It still excludes GitHub and integrations, so it is not a collaboration upgrade in those areas.

Team — $29 a month, billed monthly. Unlimited workspaces and members, private hotlinks, 30-day history, five MCP tokens per spec, 5,000 daily requests, three integrations, and three GitHub organizations target active teams. The request ceiling and integration counts remain meaningful limits.

Scale — $99 a month, billed monthly. Unlimited workspaces, members, integrations, and GitHub organizations, 90-day history, 20 MCP tokens per spec, and unlimited daily MCP requests are aimed at organizations with broad usage. Paid tiers include a free trial, while the Free plan has no stated expiration.

Platforms

OpenAPI Studio runs on the web and can be self-hosted. Self-hosting keeps deployment data in the customer's Cloudflare account, while the hosted service uses Cloudflare storage.

Who it's for

Choose it for API developers who want visual contracts, executable recipes, MCP tooling, and AsyncAPI support together. The Free plan suits a solo evaluation; Pro fits a small private project; Team is the first sensible choice for integrations and larger collaboration. Organizations requiring SSO, SCIM, or audit logs should not make it their standard platform.

Pros and cons

• Pro: Node-based API design, proxy execution, and recipe assertions connect modeling with repeatable checks.
• Pro: MCP tools, WebSocket modeling, and AsyncAPI export cover AI and event-driven workflows.
• Pro: Self-hosting, encrypted OAuth tokens, and export/deletion controls give deployment and privacy flexibility.
• Con: GitHub and integrations are blocked on Free and Pro, forcing Team for connected workflows.
• Con: SSO, SCIM, and audit logs are missing, limiting enterprise administration.
• Con: MCP quotas and short history windows on lower tiers can constrain busy teams.

Alternatives

API Design Tools is the broader category to browse when you want to compare several API-focused products.

Apidog is a better fit if you need desktop operating-system coverage alongside web and self-hosting, with a free four-user plan.

Apollo Studio suits GraphQL-oriented teams seeking a free tier for up to three developers, with a 60-requests-per-minute router limit and one-day retention.

Microcks is the alternative when a 100% open-source, community-driven CNCF Incubating project is the priority.

Pact is an open-source tooling option for teams focused on contract testing.

Postman is worth considering for its broad API client and core tools on the free plan.

TypeSpec is a free Microsoft-built, community-supported project for a code-oriented specification workflow.

Assertible fits teams wanting hosted service testing, with a free Personal plan covering two services.

GraphQL Hive is the alternative for GraphQL schema operations and a free Hobby tier.

Verdict

OpenAPI Studio is a strong choice for developers and small teams that want visual API modeling, executable recipes, MCP access, and WebSocket support in one product, especially when self-hosting matters. Choose Team or Scale for integrations and substantial MCP use. Look elsewhere when SSO, SCIM, audit logs, or mature enterprise governance are mandatory.