ZecPy: private Zcash for Python

Zero leaks, measured

A proxy between wallet and server logged every request across create, sync, receive, restart and send. These are the requests that identified the wallet.

ZecPy: 0
zcash-devtool: 7
zingo-cli: 71

How it is measured Then on public testnet, over Tor 108 requests from the shop. None identified it outside the opt-in memo fetch, which hid the real payment among 7 real ones. Read the run

See it run

ZecPy Live replays a real run on a local chain. Every request the server receives lands in the table as it arrives.

Sixteen transaction ids requested in two shuffled fetches of eight; two are marked Ours, fourteen Decoy — Memo fetch: 2 real transactions hidden among 16.

The offline signer's summary: spends 0.01 ZEC, pays 0.002 ZEC, 0.0079 ZEC change, fee 0.0001 ZEC — Cold signer: checks change against its own key.

Read the server's log

The audit's raw record. Pick a wallet; gold rows identify it.

Scenario	Request	What it asks for	Server learns
First sync	GetAddressUtxosStream	Queries transparent address UTXOs	This wallet

zcash-devtool: 7 identifying of 24 requests.

Fixed upstream

Building ZecPy found three problems in Zcash's own code. Each is filed with a fix.

Syncs reveal where the last one stoppedlibrustzcash links sessions through GetTreeState #3197 PR #3198
A reorg onto a shorter branch goes unnoticedThe wallet reported 4 confirmations; the truth was 1 PR #3199
Cold signing skips Ironwood spendszcash-devtool's pczt sign exits 0, the send fails #266 PR #267

A small API

Async where it touches the network. Amounts are integer zatoshis.

invoices.create

Each invoice gets its own shielded address. Payments match on your machine: no memo, no lookup.

invoice = wallet.invoices.create(150_000, "order-77")

Full API reference

What it refuses

Transparent paymentsPrivacyError unless you opt in
Direct connectionsTor or nothing, a fresh circuit per sync and send
Lone txid lookupsMemos fetched among 7 decoys
A sync trailTree states at aligned heights only
Mempool watchingPayments are seen in blocks

Install to paid

pip install zecpy on Linux or macOS, Python 3.10+. Nothing to compile.

from zecpy import Wallet

wallet, mnemonic = await Wallet.create(
    "./shop", network="test",
    server="https://testnet.zec.rocks:443")
invoice = wallet.invoices.create(150_000, "order-77")
async for event in wallet.invoices.watch():
    if event.invoice_settled:
        ship(event.invoice.reference)

Install

pip install zecpyseconds

Receive

invoices.createown address
payment detectednext block
payment confirmed3 blocks

Send

prove and sign locallyabout 11 s
fee10,000 zat

Identifying requests0

Agent ready

The docs ship as plain text for models. Paste the brief, or point your agent at llms.txt.

Agent brief

You are writing Python that uses ZecPy, an SDK for shielded Zcash.
Reference: https://zecpy.pages.dev/llms-full.txt

- Network calls are async: await Wallet.create, sync, send, pay.
- Amounts are integers in zatoshis. 1 ZEC = 100_000_000.
- Never print, log or return the mnemonic.
- Take payments with wallet.invoices.create and invoices.watch.
  Match by invoice, never by memo.
- Pay links with wallet.pay(uri, max_zat=BUDGET). Never raise
  max_zat to make a payment go through.
- PrivacyError is a refusal, not a bug. Do not pass
  allow_transparent or allow_pool_crossing unless asked.
- Keep tor=True. Use network="test" until told otherwise.