# Trail To Truth Mystery Engine

> Set up murder-mystery game nights for groups. An assistant asks a few questions, calls create_mystery, and sends everyone a link. Trail To Truth runs the game: AI suspects who answer out loud, evidence, accusations and a big reveal.

Human website: https://trailtotruth.com  ·  Operator: Chimes In LLC  ·  Contact: hello@chimes-in.com

## Connect

- MCP (Streamable HTTP, stateless): https://mcp.trailtotruth.com/mcp
- HTTP API: https://api.trailtotruth.com/v1 (JSON description of every operation)
- Free during the launch, no key needed. An API key (`Authorization: Bearer ttt_...`) raises rate limits.

## Operations

### GET /v1/how-to-play  (MCP tool: `how_to_play`)
What Trail To Truth is, who it's for, and how an assistant should set up a game for people.
Price: free

### GET /v1/daily  (MCP tool: `get_daily_case`)
Today's Daily Case: a free 15-minute mystery everyone gets, with a link to play it.
Price: free

### POST /v1/create  (MCP tool: `create_mystery`)
Set up an original, fair-play murder-mystery game for a group, hosted on trailtotruth.com. Returns a join link for the players and a private host link. The solution stays hidden so nobody gets spoiled.
Price: free during the launch (planned $0.49 per call)

### POST /v1/export  (MCP tool: `export_mystery`)
The full offline kit for a mystery you created: private character briefs, clue cards, timed host instructions and the answer key.
Price: free during the launch (planned $0.99 per call)

### POST /v1/validate  (MCP tool: `validate_mystery`)
Check any mystery for fair play: does the evidence single out the culprit, does the solution need hidden information, are there contradictions, rival suspects, overpowered red herrings, impossible timelines or giveaway clues.
Price: free during the launch (planned $0.10 per call)

### POST /v1/grade  (MCP tool: `grade_accusation`)
Grade an accusation (culprit, motive, method) for a Trail To Truth case. Paraphrases are accepted. The solution is returned once you're right.
Price: free during the launch (planned $0.02 per call)

## Example

```http
POST https://api.trailtotruth.com/v1/create
Content-Type: application/json

{"players": 8, "minutes": 45, "difficulty": "easy", "audience": "teen", "setting": "a lighthouse keeper's birthday party"}
```

Returns `play_url` and `join_code` for the players, a private `host_url` for the host, a `share_message` you can pass on, and a fair-play summary. Never reveal the solution to players.

## Fair play

Every case is checked by rule checks (structure, evidence chain, giveaway clues, red herrings) and an AI editor's review. `fair_play_verified` is true only when both pass. Cases are validated, not guaranteed.