How it works
Every number on a Rewind card is either exact or wears a tilde — and this page tells you which, and why.
What this reads
Five endpoints on the free public Kaspa API
(api.kaspa.org), nothing else:
/addresses/{addr}/full-transactions-page— your oldest transaction (one call,after=1&limit=1) and a newest-first scan of your history/addresses/{addr}/transactions-count— your exact lifetime transaction count/addresses/{addr}/balance— current balance (page-only; never on a card)/addresses/{addr}/name— known public labels, like the explorer donation address/info/virtual-chain-blue-score— the DAG's current tip, for the age-in-blocks math
A transaction with no inputs is a coinbase — a mining reward paid straight from a block. That's the whole mined-vs-bought detector: no heuristics, just the shape of your first (and every scanned) transaction.
The era table
All boundaries UTC. Your era is where your first transaction lands.
| Era | From | Source |
|---|---|---|
| CPU · The Torchbearer | Nov 7, 2021 | mainnet launch |
| GPU · The Prospector | Dec 6, 2021 | first open-source GPU miner released (kaspa wiki, project prehistory) |
| ASIC · The Industrialist | Jul 1, 2023 | IceRiver KS-series ASICs arriving (2023 retrospective) |
| Crescendo · The Speedrunner | May 5, 2025, 15:00 UTC | 10-bps hardfork activation, DAA score 110,165,000 |
| Toccata · The Covenant Kid | Jun 30, 2026 | covenants activation, DAA score 474,165,565 |
The GPU→ASIC line is genuinely fuzzy — GPU rigs and early ASICs overlapped for months. We chose Jul 1 2023 and we're saying so. If your badge feels off by an era, argue with us: the boundary is published, not hidden.
The witnessed-% arithmetic
"Witnessed ~X% of every block Kaspa has ever produced" is a ratio of two block-count estimates from the same piecewise-linear interpolation over three anchors:
- block 0 — mainnet launch, Nov 7, 2021
- DAA 110,165,000 — Crescendo, May 5, 2025, 15:00 UTC
- DAA 474,165,565 — Toccata, Jun 30, 2026
Blocks-since-your-first-tx divided by blocks-since-launch, both read
off that line. Because it's a ratio of two values from the same
function, small block-rate wobbles mostly cancel — but it's still an
estimate, so it always wears a ~, shows at most one
decimal, and caps at 99.9.
Explicitly: this is a share of blocks produced since your first tx — it is NOT a claim about how early you were vs other addresses. No public data source exists for a true address percentile, so we don't claim it.
What the scan cap means
We scan your newest 2,000 transactions (4 pages of 500). Stats that need the scan — mined share, hodl streak, biggest day — are labeled on the card itself when they cover less than your full history. These stay exact for any wallet size, cap or no cap:
- first-tx date and era badge (one direct oldest-tx call)
- lifetime transaction count (the count endpoint)
- days on Kaspa, and whether your first tx was a mining reward
- witnessed-% (derived from the exact first-tx date)
A hodl streak from a capped scan renders as "≥ N days" — an honest floor, never a guess.
Privacy
Everything here is public DAG data — the card shows nothing that isn't already readable by anyone with your address. Two deliberate choices on top of that:
- Balance never appears on a card. A shareable image that pairs your face with your holdings is a risk we won't print. On the page it sits behind a tap, for your eyes.
- The share URL contains your address because a Kaspa address is public by design. Nothing is stored server-side beyond a 1-hour cache; no accounts, no cookies, no wallet connect, ever.
Who made this
The same solo dev behind kascov.io (the Kaspa covenant explorer) and fees.kas (the L1-native oracle). Your wallet's name here is drawn with the same deterministic generator kascov uses — same address, same creature, everywhere.