Crate brk_oracle 

Pure on-chain BTC/USD price oracle.

Detects round-dollar transaction patterns ($1, $5, $10, … $10,000) in Bitcoin block outputs to derive the current price without any exchange data.

Behavior changes by height along two independent axes, each in its own module:

• EMA regime (config): below START_HEIGHT_SLOW prices come from the baked pre-oracle tape. From there to START_HEIGHT_FAST a slow cold-start EMA runs with a shape-anchoring restoring force. At START_HEIGHT_FAST it switches to a fast EMA that tracks mature-market volatility.
• Output filter (filter): below PaymentFilter::MODERN_TX_OUTPUT_FANOUT_CAP_START_HEIGHT batch-payout transactions are capped strictly. Above it the cap relaxes but still drops very large fan-outs.

The two boundaries differ on purpose. The EMA must hand off to fast before the 2020 crash, while the output cap helps the thin pre-2020 mix for longer and still prevents modern fan-out clusters from dominating one EMA slot.

Structs

Config

Oracle

PaymentFilter

Round-dollar payment filter.

Constants

BINS_PER_DECADE

NUM_BINS

START_HEIGHT_FAST

Height where the oracle switches slow -> fast EMA (default). The regimes are complementary: slow resists the round-USD half-price drift that locks fast below here, while fast tracks the 2018-2019 crashes that lock slow.

START_HEIGHT_SLOW

First height the oracle computes on-chain, with the slow cold-start EMA (slow). Below it, prices come from pre_oracle_prices_from.

VERSION

Oracle algorithm version. Bump on any change that alters computed prices so downstream consumers can invalidate cached results.

Functions

bin_to_cents

Converts a fractional bin to a USD price in cents. For a $D output at price P: sats = D * 1e8 / P, so P = 10^(10 - bin/200) dollars, where 10 = log10($100 reference * 1e8 sats/BTC).

cents_to_bin

Converts a USD price in cents to a fractional bin (inverse of bin_to_cents).

pre_oracle_price_cents

Baked pre-oracle price at height, or None once on-chain oracle prices start.

pre_oracle_prices_from

Baked pre-oracle prices starting at start_height, as a one-pass iterator.

sats_to_bin

Maps a satoshi value to its log-scale bin index. bin = round(log10(sats) * BINS_PER_DECADE).

seed_bin

Initial reference bin for processing height START_HEIGHT_SLOW.

seed_price_cents

Baked exchange price for the block immediately before on-chain oracle prices start.

Type Aliases

HistogramEma

Smoothed EMA over the window, one f64 per bin. The stencil search reads it, never serialized (projected to HistogramEmaCompact for the wire).

HistogramEmaCompact

Quantized u16 projection of HistogramEma for the histogram/ema/* wire.

HistogramRaw

Per-bin integer counts on the oracle log scale: used for both oracle-eligible payment histograms and unfiltered output histograms.