This small Go program audits the Zcash supply by using naive RPC calls. Effectively reconstructs the UTXO set in-memory in a map by iterating through every transaction in every block through zcashd, and keeps track of each shielded pool based on entry and exit into transparent addresses.

You need Golang installed (tested on version 1.11.5), a fully synced zcashd node, zcashd to be in your $PATH, and the txindex=1 option set in your zcash.conf

Also note that it is slow and memory intensive. This is an extremely naive implementation; based on my testing for around ~470,000 blocks it may use up to ~12GB of free RAM to conduct the audit (in addition to whatever memory zcashd is using). The sample audit added to this repo took 135m to compute. YMMV.

Have zcashd running in another process, then run the main script:

go run main.go

Then grab a coffee or two...or ten. It'll be a while.

PRs are welcome, particularly for people who make it more efficient. :)

zcashd says current height is 479827, auditing to that height.
At height 10000:
Maximum Allowed Zatoshis: 3125312562500
Public + Shielded: 3113242426967
Public UTXO Zatoshis: 3089689326427
Sprout Zatoshis: 23553100540
Sapling Zatoshis: 0
All good! Everything checks out ok 👍
Haven't reached tip of blockchain, continuing...
At height 20000:
Maximum Allowed Zatoshis: 12501250000000
Public + Shielded: 12485006934974
Public UTXO Zatoshis: 12419716255402
Sprout Zatoshis: 65290679572
Sapling Zatoshis: 0
All good! Everything checks out ok 👍
...
...
At height 479827:
Maximum Allowed Zatoshis: 587285000000000
Public + Shielded: 587269844155807
Public UTXO Zatoshis: 552368082693859
Sprout Zatoshis: 25738780979868
Sapling Zatoshis: 9162980482080
All good! Everything checks out ok 👍