Plan 2a: Broadcaster + Ethclient (stacked on Plan 1)

[117l11]

Base: feat/middleware-foundation — stacked on Plan 1. Retarget to develop after Plan 1 merges.

Summary

• Rust broadcaster crate that subscribes to eth_tx(Pending) in SpacetimeDB, builds + signs EIP-7702 type-4 txs, submits to Base Sepolia, watches receipts, and writes back via middleware reducers.
• Middleware hardening: trust-on-first-use claim_gateway_identity, deleted stale set_gateway_identity / ABI stubs, Burner7702 default now points at the Base Sepolia deploy (0x1ff0…F013).
• Startup reconcile recovers rows stuck in Broadcasting/Broadcast and rebootstraps the operator nonce from the RPC.
• Integration harness (anvil fork + spacetime CLI wrappers) + live Base Sepolia smoke script.
• .env.example template; .env updated with the new broadcaster env vars.

What's inside

Area	Tasks	Key files
Middleware	1–4	middleware/src/{claim_gateway_identity,lib}.rs, config default
Broadcaster scaffold	5–11	broadcaster/Cargo.toml, src/{stdb,error,config,signer,abi}.rs
Broadcaster runtime	12–16	src/{subscriber,submitter,watcher,reconcile,main}.rs
Tests	17–19	broadcaster/tests/{helpers,integration_anvil}.rs, tests/smoke/test_broadcaster_flow.sh
Env	20	.env, .env.example, .gitignore

Test plan

• cargo build -p broadcaster
• cargo test -p broadcaster — 13 unit tests pass
• Missing-env path: binary exits 1 with Config("missing RPC_URL")
• cargo test -p broadcaster --test integration_anvil -- --ignored --skip test_end_to_end_send_eth_flow — 2/2 scaffolds pass
• cargo test -p broadcaster --test integration_anvil -- --ignored test_end_to_end_send_eth_flow (needs SpacetimeDB @ :3000 with gateway2_test)
• ./tests/smoke/test_broadcaster_flow.sh against live Base Sepolia (needs funded burner + Alchemy RPC + running broadcaster binary)
• Flesh out bodies of test_underfunded_burner_marks_row_failed_without_broadcasting and test_crash_mid_submit_reconciles_on_restart

Notes for reviewers

• WALLET_PRIVATE_KEY / WALLET_PASSPHRASE are kept in .env as deprecated fallbacks; broadcaster reads only OPERATOR_KEYSTORE_PATH + OPERATOR_KEYSTORE_PASSPHRASE. Removed in Plan 2b.
• Broadcaster verifies the on-chain chain_id matches env before doing anything, and waits up to 5s for app_config.gateway_identity to match its SpacetimeDB identity before starting the submit loop.
• Reconcile is bounded to 60s + RECONCILE_SCAN_BLOCKS (default 20) recent blocks when walking for a lost tx hash.

[vercel]

The latest updates on your projects. Learn more about Vercel for GitHub.

Project	Deployment	Actions	Updated (UTC)
stk2eth	Ready	Preview, Comment	Apr 19, 2026 6:58pm
stk2eth-ussdgeth	Error		Apr 19, 2026 6:58pm

[117l11]

Live validation on Base Sepolia ✅

End-to-end USSD send-eth flow exercised against real infrastructure (local SpacetimeDB + Alchemy Base Sepolia):

• Tx: 0x799b908ed8b2b59fe4d2ac8266b06335d00684255c8b082ce8373ff61092dfef
• Type: 0x4 (EIP-7702)
• authorizationList: 1 entry, delegate = 0x1ff0A24D1145d58Ea6F190569C10916E1a78F013 (Burner7702)
• Operator: 0x60537D3Dc74E7Fc2d85b0AE8df341Ab2e2e703Bd
• Sender burner → Recipient burner: 0x8220…a884 → 0x2b72…649c, value 10000000000000000 wei (0.01 ETH)
• On-chain recipient balance confirmed: 10000000000000000

Two fixes added during validation

• 5d53186 middleware: send-eth amount is now converted from decimal ETH ("0.01") to wei ("10000000000000000") before eth_tx.insert. Prior behaviour left rows stuck in Broadcasting because the broadcaster parses value as wei via U256::from_str. Conversion is string-based (no f64 rounding) via new eth_decimal_to_wei helper.
• 620b229 broadcaster: DbContext::identity() internally calls try_identity().unwrap(), which panics if the SpacetimeDB WS handshake hasn't completed. main.rs now polls try_identity() for up to 5s before comparing against app_config.gateway_identity.

Still open (not blocking)

• Flesh out the two #[ignore] scaffold tests (test_underfunded_burner_marks_row_failed_without_broadcasting, test_crash_mid_submit_reconciles_on_restart).