PROTOCOL STACK
The Protocol Stack
Four open specifications doing four jobs. Aethelforge speaks all of them because the industry will not consolidate on one.
THE ANSWER
Which protocols does Aethelforge support?
Aethelforge supports four open agent-commerce protocols: MCP (tool-calling context), ACP (commerce handshake), AP2 (agent payment authorization), and x402 (HTTP-native micropayments). Each does one job; together they form the complete stack for gated machine-to-machine transactions.
Model Context Protocol
Standardized tool-calling surface between LLMs and external data sources.
Agentic Commerce Protocol
Cryptographic handshake for machine-to-machine commerce transactions.
Agent Payments Protocol
Agent-mediated payment authorization and settlement protocol.
HTTP 402 Native Payments
HTTP-native micropayments using the long-dormant 402 status code.
Why four
Because they do different jobs. MCP standardizes how a model discovers and calls your capabilities — it's a context protocol, not a commerce one. ACP handles the commerce-specific handshake when negotiation is required. AP2 answers “how do we know this agent is allowed to spend this money?” x402 answers “how do we settle small amounts inline with an HTTP response?” Any real agent transaction uses a stack, not a single line.
The bet Aethelforge makes is that trying to pick one winner here is the wrong move. The industry already signals fragmentation — Anthropic, OpenAI + Stripe, Google, and Coinbase all backing different pieces of the stack. The right position is to speak all of them fluently and translate at the gate.
Start here
If you're a merchant, the protocol you care about first is ACP — it's the one that defines the commerce handshake. If you're building an agent, start with MCP and then add commerce support through whichever of the others fits your use-case. If you're a finance or compliance person, go straight to AP2 — it's the only one that answers your questions head-on.