Did a comparison on 5 agent wallets. Here's what I found

Been experimenting and testing out payment tools for agents, specifically agent wallets that run on crypto/stablecoin rails. Many of these are focused on a specific blockchain or stablecoin, others focus on more on being multichain, or take pride on being self custodial or very secure. So I think even though they all roughly do the same thing and can be relatively easily integrated to your agent, the differentiating factor is in the small details. Wallet Custody Chains x402 Spend Controls Standout Coinbase Non-custodial, keys in TEEs on their infra, never exposed to the agent or LLM Base (only one in their docs) Yes, it's the core of the product Session caps, per-tx caps, KYT screening Gasless on Base, x402 native Circle 2Yes, gasless sub-cent USDC-of-2 MPC, user holds a share, Circle can't move funds alone 8 EVM mainnets (Arbitrum, Avalanche, Base, Ethereum, Monad, Optimism, Polygon, Unichain) Yes, gasless sub-cent USDC Transfer limits, recipient allowlists, contract blocklists, time-bound A human action is needed for any movement Finance District Keys in Nitro Enclaves, FD operators cannot extract key material, full key export via the Signer Service EVM + Solana + native BTC + native Sui Yes No policy engine by design, the funded balance is the ceiling. Confirmation step on transfers, swaps quote-only by default Only one here with native BTC and Sui, and keys you can export Crossmint Your choice, 8 signer types, custodial or not is a config decision 50+ claimed, 43 named in docs. Solana yes, Sui tokenization only, no BTC Yes, dedicated payment flow Signer scopes: spending limits, recipient allowlists, expiry Widest chain coverage, you pick the custody model MetaMask Self-custodial, you hold the seed and can export it any time EVM only, 21 mainnets, no Solana Yes, via helper script, exact scheme, EVM only Guard/Beast Mode, 2FA approval, outflow limits, plus simulation and Blockaid scan pre-signing Gas paid in the token being moved, up to $10k/mo protection on subscription A couple of things stood out to me while I was doing this comparison. Metamask's x402 support is real but it's a Python helper script rather than a first class thing, exact scheme only, EVM only, no Solana. Easy to miss if you only read the landing page. Their wallet also plugs in as agent skills rather than an MCP server, so it wants Claude Code or Codex or Cursor on the other end, and the invite gate is gone, it's just an npm install... for now. Crossmint's custody model isn't really a property of the product, you pick a signer and that decides it. Device or passkey means the user holds keys, server or cloud KMS means your org does. Worth reading their signers page before assuming which one you've ended up with. Circle is the odd one out on posture, 2 of 2 MPC means a human share is in every signature, so nothing moves fully unattended by design. Think this is a big tell on who their target users are. The pattern overall is everyone has solved "the LLM must not hold the key" and then they diverge on where the brake goes. Coinbase puts it in policy before signing. Circle puts a human inside the signature. Metamask puts it in what you see before approving. Crossmint lets you choose, which is the bit I'd expect people to misconfigure. Finance District went the other way and deliberately didn't build a policy engine, the position being that the funded balance is the ceiling, fund it with $50 and the worst case is you lose $50. Which I think for now that we are early in this space it makes sense, I don't see many people trusting their agents with more than a couple of hundred bucks to begin start playing around and experimenting with the tech. I'm planning to do some more testing, more specifically I'm curious to give the agent a bit more liberty and see what decision it makes on its own, obviously with a small amount to begin with and progressively scale it. Has anyone tried any of these? Or done some testing on agent payments yourselves?