Ports the MPC-signing integration shape from PR #4 (sdk/python tree)
into the parallel src/agents/extensions/web3 tree so issue #3 is closed
on both code paths.
Adds:
* src/agents/extensions/web3/mpc_client.py — async, pydantic-typed
HTTP client for a hanzoai/mpc bridge (mirrors the sdk/python
interface introduced in PR #4 byte-for-byte: same MpcConfig,
KeygenResult, SignResult, VerifyResult, same /v1/{keygen,sign,verify}
wire protocol, same retry/backoff semantics, same MpcError).
* src/agents/extensions/web3/tests/test_wallet_mpc.py — 20 tests
covering the MPC client (happy paths, 4xx no-retry, 5xx retry &
exhaust, api-key header, hex validation), EIP-191 sign/verify
round-trip on AgentWallet, MPC routing only when configured, and
Web3Wallet.call_contract calldata forwarding.
Changes:
* src/agents/extensions/web3/wallet.py
- call_contract: replaces NotImplementedError with a real
web3.py ABI-driven call. Supports read (eth_call) and write
(sign + send) paths. Accepts an explicit ABI or synthesizes a
minimal one from a Solidity-style signature.
- verify_signature: replaces return True placeholder TODO with
eth_account.Account.recover_message + encode_defunct (EIP-191).
Returns False on malformed input rather than raising.
- sign_message: now produces EIP-191 signatures (matches
Account.sign_message), so the verify side round-trips. Adds
sign_digest for raw-hash signing.
- MockWallet: backed by a real eth_account.Account so signing
round-trips through verify_signature in tests.
- AgentWallet: optional mpc_client= constructor arg, has_mpc
property, async sign_via_mpc() routes a digest through the
cluster when configured.
* src/agents/extensions/web3/__init__.py — re-exports the new MPC
symbols and Web3Wallet/MockWallet; documents why Web3Agent /
Web3Network are deferred (they reference Agent.InferenceResult /
State which moved during the src/agents refactor — out of scope
here, follow-up).
Verification:
* pytest src/agents/extensions/web3/tests/ -v -> 20 passed
* pytest tests/ -> 316 passed (no regression)
* ruff check src/agents/extensions/web3/{mpc_client,wallet,__init__}.py
src/agents/extensions/web3/tests/ -> all checks passed
Refs:
* Issue #3 — web3 extension: implement MPC-signing integration
* PR #4 — sdk/python parallel: feat(web3): MPC-signing integration
