We're working on spend controls for AI agents using MPP. The protocol handles how agents pay, but there's no standard way to enforce budgets before payment happens.
How people here are handling this. When your agent hits a $35 API call, or gets stuck in a retry loop on a $0.50/req service, what stops it from draining the wallet?
Are wallet-level caps enough? Are you writing custom budget checks in your agent code? Or just not worrying about it yet?
We built an open source MCP proxy (github.com/policylayer/intercept) that enforces policy on tool calls. Thinking about extending it to read the -32042 payment challenge, check the amount against a budget, and allow/deny/hold for approval before the wallet pays.
Would love to hear if this is a real pain or a theoretical one.
Nice kit. One gap in x402 flows: no standard way to express "this agent can spend up to $X/day on these API categories." Payment primitive works, but the authorization/policy layer is ad hoc. Working on this at PolicyLayer — programmable spend policies for agent wallets.
A real-time Kanban board for monitoring Claude Code tasks. See what Claude is working on, track dependencies between tasks, and add notes that Claude can read.
AI agents need to make autonomous payments, but if you give them direct wallet access, they can drain your funds. Custodial solutions create liability and trust issues. Building custom controls takes weeks.
## The Solution
A two-gate enforcement model:
1. *Gate 1 (Validate)*: Agent requests payment → Policy engine checks limits → Issues single-use authorization token
2. *Gate 2 (Verify)*: Before signing → Verify token + check for tampering → Only then sign transaction
Your keys never leave your infrastructure. Policy enforcement happens before signing.
Currently demonstrated with Tether WDK on Ethereum, but the wrapper pattern works with any wallet SDK.
We at Shoply.com share a vision with Gumroad about simplifying and democratizing ecommerce. We too started out as a pure widget play with the idea being sellers would leverage their existing networks to drive sales.
It turns out 'average joe' doesn't have twitter/facebook networks anywhere near sufficient size to generate decent level of sales. Just like they need help with tech aspects of selling online, so they need help with the marketing/sales and traffic elements.
We at Shoply dealt with this by aggregating products from all our sellers together into a centralised marketplace. Doing so allows us to help them by providing them an ongoing in-built sales channel too, alongside a quick and easy way to list products for sale and take payment
I expect Gumroad will experience a similar situation where sellers look to them to help boost distribution and ultimately sales.
as a seller thats right - the tour page is a great landing page, but we also need to appeal to buyers so are caught in a place where the homepage needs to talk to 2 different markets at the same time
we're a/b testing a few homepages - you must have got the getting straight down to business one - some people really like it, others things its a little pushy
much simpler to use and quicker to setup. free plans with no monthly fees, socially integrated (sell on facebook etc) and we help with traffic and sales through our marketplace and networked checkout.
Shopify is a great solution - but we want to help more casual/hobby sellers - and they find shopify a little complicated
How people here are handling this. When your agent hits a $35 API call, or gets stuck in a retry loop on a $0.50/req service, what stops it from draining the wallet?
Are wallet-level caps enough? Are you writing custom budget checks in your agent code? Or just not worrying about it yet?
We built an open source MCP proxy (github.com/policylayer/intercept) that enforces policy on tool calls. Thinking about extending it to read the -32042 payment challenge, check the amount against a budget, and allow/deny/hold for approval before the wallet pays.
Would love to hear if this is a real pain or a theoretical one.