feat: add zcash wallet and mediator services

[macterra]

Summary

Adds transparent-only Zcash wallet and mediator services. The wallet matches the satoshi-wallet HTTP contract as closely as practical while using Zebra for chain/address-index/broadcast RPCs and Keymaster for mnemonic-backed local signing. The mediator mirrors the satoshi-mediator import/export flow for ZEC:* registries.

What changed

• Added services/mediators/zcash-wallet with deterministic transparent derivation, Zebra RPC support, wallet routes, local transaction signing, send/anchor support, and explicit unsupported fee bumping.
• Added services/mediators/zcash to scan Zebra blocks for OP_RETURN batch DIDs, import discovered batches, export Gatekeeper queues through zcash-wallet, and publish block metadata.
• Added Docker/compose wiring, sample env entries, docs, ZEC registry support in TypeScript/Rust Gatekeeper validators, and focused registry/wallet tests.
• Added repo guidance documenting Zebra-backed transparent-only wallet behavior and ZEC registry naming.

Validation

• npm run build in services/mediators/zcash-wallet
• npm run build in services/mediators/zcash
• npm test -- --runTestsByPath tests/gatekeeper/utils.test.ts tests/wallet/zcash-derivation.test.ts tests/wallet/zcash-wallet.test.ts --runInBand
• cargo check --manifest-path rust/services/gatekeeper/Cargo.toml
• git diff --check
• Live read-only Zebra smoke against http://100.70.86.134:8232/: getblockcount, address-index RPCs, and verbosity-2 block shape for mediator scanning.

No broadcast was attempted. cargo fmt --check --manifest-path rust/services/gatekeeper/Cargo.toml still reports pre-existing formatting drift across the Rust service beyond this change.

[Copilot]

Pull request overview

Adds Zcash (transparent-only) support to Archon by introducing a Zebra-backed wallet service (Keymaster mnemonic + local signing) and a companion mediator that scans/anchors OP_RETURN batch DIDs, plus wiring/testing/docs to integrate ZEC:* registries end-to-end.

Changes:

• Introduces new zcash-wallet HTTP service (Zebra RPC + local transparent signing) and new zcash mediator (scan/import/export + metrics).
• Extends Gatekeeper registry validation to include ZEC:mainnet and ZEC:testnet (TypeScript + Rust) and updates sample configuration.
• Adds Dockerfiles/compose integration and Jest tests covering derivation and RPC-backed wallet behavior.

Reviewed changes

Copilot reviewed 33 out of 37 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests/wallet/zcash-wallet.test.ts	New Jest coverage for RPC-backed wallet flows (setup, balance/UTXO normalization, anchoring).
tests/wallet/zcash-derivation.test.ts	New tests for derivation, coin type selection, and OP_RETURN size validation.
tests/gatekeeper/utils.test.ts	Updates registry listing tests to include ZEC:* registries.
services/mediators/zcash/tsconfig.json	TypeScript build config for the Zcash mediator package.
services/mediators/zcash/src/zcash-mediator.ts	New mediator service: scans Zebra blocks for OP_RETURN batch DIDs; imports/exports via Gatekeeper/Keymaster and zcash-wallet; exposes metrics.
services/mediators/zcash/src/types/bitcoin-core/index.d.ts	Local bitcoin-core type shim for the mediator’s RPC usage.
services/mediators/zcash/src/types.ts	Shared mediator DB/types (discovered items, registry block verbosity, etc.).
services/mediators/zcash/src/db/sqlite.ts	SQLite persister backend for mediator state.
services/mediators/zcash/src/db/redis.ts	Redis persister backend for mediator state.
services/mediators/zcash/src/db/mongo.ts	MongoDB persister backend for mediator state.
services/mediators/zcash/src/db/jsonfile.ts	JSON-file persister backend for mediator state.
services/mediators/zcash/src/db/abstract-db.ts	Shared locking updateDb implementation for persisters.
services/mediators/zcash/src/config.ts	Env-driven configuration for the Zcash mediator.
services/mediators/zcash/README.md	Mediator documentation: responsibilities, env vars, notes on fee bumping behavior.
services/mediators/zcash/package.json	Package metadata/deps for the Zcash mediator.
services/mediators/zcash/data/.gitignore	Ignores persisted mediator state in services/mediators/zcash/data.
services/mediators/zcash-wallet/tsconfig.json	TypeScript build config for the Zcash wallet service package.
services/mediators/zcash-wallet/src/zcash-wallet.ts	New wallet core: address tracking, balance/UTXO views, local tx building/signing/broadcast, OP_RETURN anchoring.
services/mediators/zcash-wallet/src/zcash-rpc.ts	Zebra JSON-RPC client wrapper.
services/mediators/zcash-wallet/src/wallet-api.ts	New Express HTTP API matching satoshi-wallet contract (admin-key gated) + metrics.
services/mediators/zcash-wallet/src/derivation.ts	BIP44 transparent derivation and address generation for Zcash (mainnet/testnet).
services/mediators/zcash-wallet/src/config.ts	Env-driven configuration for the Zcash wallet service.
services/mediators/zcash-wallet/package.json	Package metadata/deps for the Zcash wallet service.
services/mediators/zcash-wallet/package-lock.json	Lockfile for the Zcash wallet service dependencies.
sample.env	Adds ZEC-related env examples and includes ZEC:mainnet in Gatekeeper registries.
rust/services/gatekeeper/src/api.rs	Allows ZEC:mainnet/ZEC:testnet in Rust Gatekeeper registry validation.
packages/gatekeeper/src/gatekeeper.ts	Allows ZEC:mainnet/ZEC:testnet in TS Gatekeeper registry validation.
package.json	Adds @bitgo/utxo-lib dependency at repo root (needed for shared/test builds).
package-lock.json	Updates lockfile for new root dependency graph.
docs/services/mediators/zcash-wallet/README.md	Wallet documentation: scope, routes, config, Zebra RPC requirements.
docs/services/gatekeeper/README.md	Documents ZEC:* as supported registries.
Dockerfile.zcash-wallet	Container build for the wallet service.
Dockerfile.zcash	Container build for the mediator service.
docker-compose.zcash-mainnet.yml	Compose stack for Zcash wallet + mediator on mainnet.
docker-compose.yml	Includes Zcash compose and adds ZEC:mainnet to explorer networks.
AGENTS.md	Adds repo guidance for Zebra-backed transparent-only wallet behavior and registry validator updates.

Files not reviewed (1)

• services/mediators/zcash-wallet/package-lock.json: Language not supported

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.