About this coin flip
Each click hits /api/ints with min=0 and max=1. The returned integers are mapped 1:1 to heads/tails — odd is tails, even is heads — and the totals are tallied for you. Because the underlying API publishes a SHA-256 hash of the server seed for every call, the flips can be independently re-derived later.
For developers
Flip 10 coins from your code in one line:
curl "https://api.provable.io/api/ints?clientSeed=YOUR-SEED&min=0&max=1&count=10"
For the full API reference see /api-docs, or the recipe page at Dice rolls & coin flips.
Frequently asked questions
Is this coin flip really 50/50?
Yes. Every flip is generated from a HMAC-SHA256 byte stream and mapped to {0,1} uniformly. The server publishes a hash of its seed, so anyone can re-derive the result.
Can I flip more than one coin at once?
Yes — up to 100 flips per click. Heads and tails are tallied automatically.
Is this fair enough for a tie-breaker?
Yes. Every flip gets a permanent permalink containing the published server hash and your client seed. Either party can re-derive the flip from those values, so the result cannot be retroactively changed.
Does this use Math.random()?
No. The flip is generated by the Provable.io API using HMAC-SHA256 over a server seed and a per-flip client seed.