Transaction review

What you get

A review sheet that runs @anywalletkit/tx-preview-evm before every EVM write. Plain sends go through policies.confirm, swaps through reviewExecution. The sheet shows:

• the simulated balance changes;
• every approval;
• the recipient and the fee;
• an ok / warn / danger verdict. Danger asks for a second, explicit confirmation.

Before you start

The wallet from the earlier prompts, ideally with swaps. An RPC that supports eth_simulateV1 gives full simulations; others fall back to simulation-unavailable.

The prompt

Paste it into your agent as is, in the project folder of the app the earlier prompts built. The raw file is prompts/03-tx-review.md.

Add a transaction review sheet to this Any Wallet Kit wallet with `@anywalletkit/tx-preview-evm`.

Read the "Transaction preview" and "Policies" parts of https://docs.anywallet.tech/llms-small.txt (or AGENTS.md in github.com/ultratestbro/anywalletkit) first, and use only APIs that appear there.

- Every EVM write is simulated before the user confirms: plain sends and contract calls through the kit's `policies.confirm`, swaps through the router's `reviewExecution` (preview the approvals and the source call as one sequence).
- The sheet shows the simulated balance changes ("-0.01 ETH", "+25.1 USDC"), every approval with its spender and amount, the recipient, and the network fee.
- A verdict from the preview's check codes: ok, warn or danger, each with one plain-language line. Danger (a revert, an unlimited approval) needs a second, explicit confirmation. "Simulation unavailable" is a warning, not a block.
- Non-EVM writes and signed messages still get a confirmation sheet, without a simulation.
- The user's own addresses count as "own" so moves between them aren't flagged as foreign.

Done when `npx tsc --noEmit` passes and `npx expo export --platform ios` bundles.

What the result looks like

src/review/preview.ts   # JSON-RPC transport, previewEvmTx, check codes → verdict + lines
src/review/Sheet.tsx    # changes, approvals, recipient, fee, verdict, second confirm on danger
src/wallet/policies.ts  # confirm → preview for eip155 writes, plain sheet otherwise

Check it works

Check that it builds with npx tsc --noEmit and npx expo export --platform ios. On a phone build:

1. Send to one of your own addresses. It must not be flagged as foreign.
2. Start a swap and confirm the approval amount equals the input.

Common failures

Symptom	Fix
Everything shows “simulation unavailable”	Your RPC has no eth_simulateV1; the module falls back to eth_call where it can, otherwise it is a warning by design
The RPC transport loses error details	Throw Object.assign(new Error(message), body.error) so code and data reach the module
Sends to your other accounts are flagged as foreign	Pass all of the user’s addresses in own

Security

Never paste a real recovery phrase into an agent chat, a prompt or a test. Use the public test phrase (abandon abandon … about) while building, then small amounts on a phone build. Read the diff the agent wrote around keys and signing: nothing should log, store or send the phrase, and every write should pass through a review step. Treat simulation-reverted and approval-unlimited as danger.

Eval

Passed on the first run: 8 min, 50 turns, $2.46, on top of the Minimal wallet result (without the swap screen, so the swap review was wired but had no caller yet). The agent tested its verdict logic in Node against a fake RPC: own-address sends, an unlimited approval, a revert, and no eth_simulateV1.