Prepare an unsigned transaction (hand-off)
prepare_txPrepare a contract WRITE for the user to sign. Returns an UNSIGNED transaction, its simulation, a human-readable summary, safety metadata, warnings, a configured signing deeplink, and an EIP-1193 wallet request when signing is recommended. IMPORTANT: this tool NEVER signs or broadcasts. Present the summary + simulation + warnings to the user. Only hand them the deeplink or wallet_request when safety.signing_recommended is true. If safety.risk_level is high or blocked, make that explicit; blocked means do not send.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| args | No | Function arguments, in order. Pass uint values as decimal strings. | |
| from | Yes | The sender address (the user's wallet). No key is needed — nothing is signed. | |
| chain | Yes | Chain alias from GET /v1/chains (for example "ethereum", "base", "monad", "bsc") or numeric EIP-155 chain id. | |
| value | No | Native value in wei (decimal string), for payable functions. | |
| address | Yes | 0x contract address. | |
| rpc_url | No | Override HTTP(S) RPC URL. Required for chains with no default (e.g. local/31337) or custom EVM chain ids. | |
| function | Yes | Function name, or full signature like "transfer(address,uint256)" if overloaded. |
Output Schema
| Name | Required | Description | Default |
|---|---|---|---|
| safety | Yes | ||
| deeplink | Yes | ||
| warnings | Yes | ||
| simulation | Yes | ||
| unsigned_tx | Yes | ||
| human_summary | Yes | ||
| wallet_request | No |