Tutorials, comparisons and design patterns for building autonomous agents that self-fund, call 345+ models and orchestrate MCP Tools.
The W3C WebMCP draft turns any web page into an in-browser MCP-style tool server via document.modelContext. We read the spec (28-Jul-2026 draft), the declarative form proposal, and Cloudflare's one-switch deployment — and map the two things the standard deliberately leaves out: agent identity and payments.
Between 2 and 7 August, Cloudflare ran its first Agents Week and published a stack that covers the four verbs it says the agentic web needs: readable, discoverable, callable, payable. Wallets and cloudflare.pay gave agents a buy side. The new MCP spec reached production infrastructure nine days after going final. Workers AI and AI Gateway merged into one control plane with cross-provider failover and a single credit balance. And OSL launched a payment rail that speaks x402, AP2 and MPP at once.
Nanopayments powered by Circle Gateway went live on mainnet on 29 April 2026: gas-free USDC payments down to $0.000001, on eleven chains, using the x402 protocol. The mechanism is not a new scheme — it is the standard exact scheme with a different EIP-712 domain, a Gateway Wallet contract as verifyingContract, and settlement deferred into a batch signed inside an AWS Nitro Enclave. We walk the whole path: deposit, 402, TransferWithAuthorization, off-chain debit, batch, withdrawal. Then the constraints the marketing does not lead with: authorizations must stay valid at least three days, deposits on Ethereum-anchored chains take 13 to 19 minutes, smart contract accounts are excluded because the batch path verifies with ecrecover, and Solana is supported by Gateway but not by Nanopayments.
The Agent Directory Service is the discovery layer of AGNTCY, the Linux Foundation project that Cisco contributed in July 2025. It stores agent records as OCI artifacts addressed by content identifier, indexes them in a Kademlia DHT keyed on a skill taxonomy, and signs them with Sigstore. We read the IETF draft end to end, audited the dir and oasf repositories, and crawled the public staging registry on 6 August 2026: 9,814 artifacts, an estimated 1,900 records, three quarters of them with no address to call and none with a price.
Until now x402 was something you installed: middleware in Express, Hono, FastAPI, an MCP wrapper. In June 2026 AWS made it a WAF rule action. In July Cloudflare announced the same capability for anything behind its edge, and on 4 August it announced the wallet for the buyer side. We read the AWS developer guide end to end, checked its claims against the x402 repo, and mapped what edge enforcement actually changes: settlement inside the request path, several seconds of admitted latency, a caching question the specification still does not answer, and identity that is probabilistic on one edge and cryptographic on the other.
x402 separates payment semantics from chain encoding. The semantics fit in half a page; the encodings fill fifteen network binding documents across EVM, Solana, Stellar, TON, NEAR, Aptos, Hedera, Algorand, Keeta, Concordium, Cardano, Casper, Starknet, Sui and XRPL. We read all of them, cloned the repo, and mapped what each chain does when it has no EIP-3009 — plus where the specs, the SDKs and the docs disagree.
ACP bundles checkout and payment into one token. UCP does not: it defines Payment Handlers as specifications anyone who owns a domain can publish, and negotiates which ones apply on every single transaction. We walk the /.well-known/ucp profile, the four-step capability intersection, the trust triangle, the RFC 9421 identity layer that turns out to be the same machinery as Web Bot Auth and Visa's TAP, and the AP2 mandate extension that locks a session once negotiated. Then we audit the repo at commit a839e99: 236 commits, 79 open PRs, a spec whose last tagged release is four months old while the docs render draft, a plural capability name in the playground that can never intersect, and zero occurrences of x402, stablecoin, or USDC anywhere in the specification.
Visa's Trusted Agent Protocol signs who is knocking. Verifiable Intent signs what the human approved. It is a layered SD-JWT credential chain — issuer to user to agent — where the user's constraints are cryptographically bound and the agent's final values must satisfy them. We walk the three layers, the split L3, the eight registered constraint types, and the point where the spec admits cryptography stops and stateful ledgers begin. Then we audit the repo: a draft frozen since April, an RFC 9901 conformance bug that makes standard verifiers reject every L2 it issues, and a reference constraint checker that defaults to the permissive path.