Agentcast

agentcast-mcp

An MCP server that gives AI assistants the ability to enforce structured output: extract JSON from messy LLM text, gate it against a shape spec, and produce the retry feedback message when the model returns the wrong shape.

Built on top of @mukundakatta/agentcast. Works with Claude Desktop, Cursor, Cline, Windsurf, Zed, and any other MCP client.

Tools exposed

extract_json

Pull a JSON value out of messy LLM output. Tries the whole text, then a fenced ```json ``` block, then the largest balanced {...} / [...] substring. Returns the parsed value plus which strategy succeeded.

{
  "text": "Sure, here you go:\n```json\n{\"answer\": 42}\n```\nLet me know!"
}

→

{
  "value": { "answer": 42 },
  "found": true,
  "source": "fenced_json"
}

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View the full README on GitHub