Shielded Currents

A collection of Rust tools for analyzing Zcash shielded pool activity, transaction fees, supply history, and mempool data.

These tools were originally developed inside the ZecHub wiki and have been extracted into their own repository for easier use and maintenance.

Ironwood-ready (NU6.3) as of 2026-07-23. Tracks Transparent / Sapling / Orchard / Ironwood pools.

Tools

Crate	Description
zcash-block-fees	Block-level fee totals. Default path reads spent outputs from getblock verbosity 3.
zcash-mempool-visualizer	Visualize / inspect current mempool state.
zcash-shielded-currents	Inflows, outflows, and current activity across Transparent / Sapling / Orchard / Ironwood. Fee-enabled runs use getblock verbosity 3.
zcash-supply-history	Historical shielded supply tracking.
zcash-tx-fee	Transaction fee analysis.

Prerequisites

• Rust (stable)
• A running Zebra node with RPC enabled (default: http://127.0.0.1:8232)

Node version depends on the tool:

• zcash-block-fees and fee-enabled zcash-shielded-currents require zebrad >= 7.0.0-rc.0. The default fee path is getblock verbosity 3 (--fee-source prevout). A 6.x node does not return vin.prevout and those runs will fail.
• zcash-mempool-visualizer, zcash-supply-history, and zcash-tx-fee still work with Zebra >= 6.0.0.
• --fee-source legacy keeps the old getrawtransaction input lookup. It runs on 6.x, and it is slower.

Most tools expect a local Zebra instance. Check the cookie location. Fork and customize as needed.

Ironwood (NU6.3) activates at height 3,428,143 (~2026-07-28). The node must be upgraded before that height.

Fee path

zcash-block-fees and zcash-shielded-currents no longer fetch parent transactions to price inputs. Verbosity 3 returns vin.prevout.value. A missing prevout is excluded from the fee total and counted, not stored as zero.

--skip-fees on currents stays on verbosity 2. Supply history should stay on low verbosity. Neither benefits from verbosity 3.

On zebrad 7.0.0-rc.0, blocks 3503072–3504223 match at 296269451 zat with no missing prevouts. Block-fees dropped from 4.40s to 0.62s. Currents dropped from 2.36s to 0.56s. Over 8064 blocks, block-fees dropped from 33.09s to 3.81s with a zero fee delta.

Quick Start

git clone https://github.com/dismad/shieldedCurrents.git
cd shieldedCurrents
cargo build --release

Run a specific tool

cargo run -p zcash-shielded-currents --release -- --last 500
cargo run -p zcash-block-fees --release -- --last 500 --quiet
cargo run -p zcash-mempool-visualizer --release
cargo run -p zcash-supply-history --release
cargo run -p zcash-tx-fee --release

Add -- --help after --release for each binary's flags.

Compare the verbosity-3 path with the old input fetches on a fixed height range:

cargo run -p zcash-block-fees --release -- --compare --from 3503072 --to 3504223 --quiet
cargo run -p zcash-shielded-currents --release -- --compare --from 3503072 --to 3504223

Force the old path:

cargo run -p zcash-block-fees --release -- --fee-source legacy --last 500 --quiet
cargo run -p zcash-shielded-currents --release -- --fee-source legacy --last 500

Workspace Structure

shieldedCurrents/
├── Cargo.toml
├── zcash-block-fees/
├── zcash-mempool-visualizer/
├── zcash-shielded-currents/
├── zcash-supply-history/
└── zcash-tx-fee/

This is a Cargo workspace. Build or run one crate with -p <name>, or build the set with cargo build --release.

Development

cargo check
cargo fmt
cargo test -p zcash-block-fees -p zcash-shielded-currents

The fee tests cover the status-quo formula and the verbosity-3 conversion. They do not need a node. --compare is the live check.

License

MIT OR Apache-2.0