# Coin-Flip Duel

> ⚠️ **Experimental — generated with no human supervision.** This realm was
> produced automatically by an MCP-driven agent to exercise the gno MCP server
> and tooling, and to generate test content for gno compilers, linters and
> formatters. **Not audited. Not for production.** Full context & folder README:
> [r/moul/x/daily](https://github.com/moul/gno-contracts/blob/main/r/moul/x/daily/README.md)

---


A one-on-one coin-flip duel between two addresses. The challenger picks
heads or tails and names an opponent; the opponent settles it with a single
`Accept` call, which flips the coin on the spot and records the result. No
stakes, just an on-chain win/loss record and a running champion.

Realm: `gno.land/r/g12cs4cehujpffpjpywmkqj43m6u5ya53nj69sjz/coinflipduel`

## Example calls

```
Challenge("g1bob...", "heads")   # as alice -> opens duel #1, alice called heads
Accept("1")                       # as bob   -> flips the coin, settles the duel
Cancel("2")                       # as the challenger, before it's accepted
```

## Render paths

- `` (home) — arena summary, champion, pending duels
- `<id>` (e.g. `3`) — a single duel's detail
- `<address>` — a player's win/loss record

## Toolchain

Built and tested against the local `gno` binary (`master.3130+bf5b31eda`).
`gno test .` passes; see the injected build brief for the sapphire (gno 0.9)
API notes this realm follows (`chain`, `chain/runtime`, `gno.land/p/nt/avl/v0`).

## What changed in v1

Identical behaviour to [`v0`](https://github.com/moul/gno-contracts/tree/4f2df83869b80470eb81c48a82fdbe82256b8113/r/moul/x/daily/coinflipduel) apart from rendering, which now goes
through [`p/moul/kit/ui`](/p/moul/kit/ui/v0) instead of the local `escapeInline` helper.

**Real escaping.** The local helper replaced a handful of markdown metacharacters. `ui.Inline` and `ui.Cell` delegate to [`p/nt/markdown/sanitize`](/p/nt/markdown/sanitize/v0), which also strips bidi and zero-width characters and folds newlines, so user text cannot reorder or escape the line it sits on.

The rendering change means the output differs from v0, which under this repo's versioning rule is a compatibility change, hence a new version rather than an edit in place. `v0` stays live and untouched.

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---

Part of **[moul/gno-contracts](https://github.com/moul/gno-contracts)** — moul's versioned gno.land contracts. See the repository for the full catalog, build/test tooling, and usage.

**Dependency graph:**

![gno.land/r/moul/x/daily/coinflipduel/v1 dependency graph](https://raw.githubusercontent.com/moul/gno-contracts/main/_assets/gno.land/r/moul/x/daily/coinflipduel/v1/deps.png)

> 🧪 **Highly experimental — potentially vibe-coded.** Not audited; may break, change, or be removed at any time. Do not use with anything of value. Full disclaimer: [DISCLAIMER](https://github.com/moul/gno-contracts/blob/main/DISCLAIMER.md).

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