Question 1

What is OrcA?

Accepted Answer

OrcA (Orchestrator for APIs and Agents) is a VS Code extension, part of the HAPI MCP Stack. It turns OpenAPI and Arazzo contracts into MCP servers inside the editor: it finds your contracts, previews their MCP tools, runs them locally with the HAPI CLI, deploys them, and registers them with your AI assistant.

Question 2

How do I turn an OpenAPI or Swagger spec into an MCP server in VS Code?

Accepted Answer

Install OrcA, open your OpenAPI 3.x file, and click Run with HAPI in the editor title bar. OrcA starts hapi serve on a free port and shows the server in the MCP Servers view; Add to VS Code then registers it in .vscode/mcp.json. Swagger 2.0 documents need converting to OpenAPI 3 first.

Question 3

Can I see which MCP tools an API will expose before running it?

Accepted Answer

Yes. OrcA's Dry Run runs hapi serve --dry-run and opens the tool list beside your contract as JSON (a ChatGPT App submission dump), Markdown (an AI-agent system prompt template), YAML, or a table. No server is started.

Question 4

What happens if port 3000 is already in use?

Accepted Answer

OrcA checks that the port is really free before starting HAPI. If port 3000 is taken, it starts on the next free port and notes it; if you chose the port yourself, it asks and offers the next free one. It never gives two of its own runs the same port.

Question 5

Does OrcA replace the runMCP VS Code extension?

Accepted Answer

Yes. The runMCP VS Code extension is deprecated and all of its features, including deploying and managing MCP servers, now live in OrcA.

One post tagged with "VS Code"

OrcA for VS Code: From OpenAPI and Arazzo to MCP Server, Without Leaving Your Editor