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Ten lines to a verdict.In the language you ship.

SDKs for Python, TypeScript, Go and Rust, a REST API with a live event stream, webhooks, a GitHub App and an MCP connector for agents. Below is the exact call behind a real run, and what came back.

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Typing the callReal run 508c1fb2 · 30 personas · pass A

Quickstart

Install. Key.Run.

Every SDK has the same shape: create a run, stream it, read the verdict. The code below is straight from each SDK's readme.

The stream

Watch the roommake up its mind.

A run streams as it happens, over server-sent events: each persona as it's seated, each reaction as it lands, and the report the moment the last one does.

persona.ready

A seat is built: archetype, voice and decision profile.

reaction.partial

A reaction arriving word by word, for live UIs.

reaction.complete

One persona's final read, with its sentiment and objections.

sim.complete

The report: the verdict, the split, the objections, the quotes.

POST /v1/sims/{id}/stream-token # a short-lived token, since EventSource can't send headers GET /v1/sims/{id}/events?token=… # the stream itself

Where it plugs in

One verdict.Four places it lands.

On a pull request, at your own endpoint, inside an agent, or in the channel your team already reads.

MCP

Your agentgets a room too.

Add one connector and the assistant you already use can put copy, ads, pages and decisions in front of a room, wait for the verdict, and tell you what it found in plain words.

The askTools from mcp.kranth.ai · result from run 508c1fb2

Connect in a minute

  1. Add https://mcp.kranth.ai/mcp as a connector in your agent.
  2. Sign in at kranth.ai and pick the workspace whose audience should read things.
  3. Ask in plain words: “Test these three headlines on B2B SaaS buyers and tell me which one to ship.”
Pre-flight, not prediction. The agent is told never to promise clicks or revenue, to relay credit and plan errors as they are, and to ask before it makes anything public.

What it can call

The reference

Every route.Try any of them live.

The full reference is interactive: every endpoint with its fields, errors and examples, runnable against your own key.

Your key

Cut a key.Run your first room.

Sign up, mint a kr_live_ key under API keys, and every account starts with 10 free credits, no card.

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