Electra Payment Index
How AI agents pay, compared
The protocols and providers that let an agent pay or get paid: what each one does, who supports it, and what it costs. Read on official pages and dated. Electra Index does not process payments.
| Protocol | Role | What it does | Pays with | Status | Providers | Tools |
|---|---|---|---|---|---|---|
| x402 x402 Foundation · Coinbase | PAY PER REQUEST | Lets a website or API ask for a small stablecoin payment inside a normal web request, so an AI agent can pay and get the data instantly. Best for: API calls, data, micro-payments, paid MCP tools | Stablecoins | LIVE since 2025-05 | 11 | 1224 |
| MPP Tempo · Stripe | PAY PER REQUEST | An open way for AI agents to pay for a service in the same web request, using stablecoins, cards or Bitcoin Lightning. Best for: API calls, paid services, session/streamed micro-payments | Stablecoins · Card · Lightning | LIVE since 2026-03 | 5 | 31 |
| L402 Lightning Labs | PAY PER REQUEST | Lets software pay a tiny Bitcoin Lightning invoice to unlock an API, and the payment receipt doubles as the login. Best for: Bitcoin micro-payments for APIs, no accounts | Lightning | LIVE since 2020-03 | 0 | 27 |
| Pay per crawl Cloudflare | PAY PER REQUEST | Lets website owners charge AI crawlers a price each time they fetch a page, with Cloudflare handling the billing. Best for: Publishers charging AI crawlers for content access | — | DRAFT since 2025-07 | 0 | 0 |
| UCP Google · Shopify | CHECKOUT | A common language so AI agents, shops and payment providers can handle product discovery, checkout and orders without custom integrations. Best for: Agentic shopping and checkout across retailers (Google Search/Gemini) | Any | SPEC PUBLISHED since 2026-01 | 6 | 10 |
| ACP OpenAI · Stripe | CHECKOUT | Lets an AI assistant like ChatGPT complete a purchase from a shop on the buyer's behalf, passing a secure payment token to the merchant. Best for: In-chat checkout of physical and digital goods | Card | SPEC PUBLISHED since 2025-09 | 5 | 1 |
| AP2 Google · FIDO Alliance | AUTHORISATION | Gives an AI agent signed, tamper-proof proof that a person really authorised a purchase, so banks and merchants can trust it. Best for: Proving user consent for agent-initiated purchases (mandates) | Card · Stablecoins · Bank transfer | SPEC PUBLISHED since 2025-09 | 3 | 8 |
| Verifiable Intent Mastercard · Google | AUTHORISATION | Creates a tamper-resistant record of what a person authorised an AI agent to do, as cryptographic proof if a purchase is disputed. Best for: Proof of user authorisation for agent purchases, dispute evidence | — | SPEC PUBLISHED since 2026-03 | 0 | 0 |
| KYAPay Skyfire | AGENT IDENTITY | Gives an AI agent a verifiable ID card and a payment token, so a service knows who the agent represents and can charge it. Best for: Agent identity verification, account creation and guest checkout | Card · Stablecoins · Bank transfer | DRAFT since 2025-06 | 1 | 0 |
| Web Bot Auth IETF Web Bot Auth Working Group · Cloudflare | AGENT IDENTITY | Lets bots and AI agents cryptographically sign their web requests so websites can verify who they really are. Best for: Verifying bot/agent identity at the CDN or website edge | — | DRAFT since 2025 | 0 | 0 |
| Mastercard Agent Pay Mastercard | CARD NETWORK | Mastercard's programme that gives AI agents special secure card tokens so they can pay on a cardholder's behalf with consent. Best for: Card payments made by AI agents on Mastercard | Card | LIVE since 2025-04 | 1 | 0 |
| Visa TAP Visa | CARD NETWORK | Lets online shops check that an AI shopping agent is genuine and approved by Visa, rather than a malicious bot. Best for: Merchants recognising trusted agents at card checkout | Card | SPEC PUBLISHED since 2025-10 | 1 | 0 |
| MCP Agentic AI Foundation · Anthropic | TOOLS | A standard plug that lets AI assistants connect to outside tools and data; payment protocols are often delivered through it. Best for: Connecting agents to tools, data and paid services | — | LIVE since 2024-11 | 8 | — |
| A2A Linux Foundation · Google | AGENT TO AGENT | A shared language that lets AI agents from different companies find each other, talk and hand over tasks. Best for: Agent-to-agent task delegation and collaboration | — | SPEC PUBLISHED since 2025-04 | 3 | 73 |
Providers = payment companies that state support on their own pages. Tools = indexed tools and agents that mention the protocol in their own description (automatic count). Status and dates come from each protocol's official documentation, checked 02 Oct 2026.