A useful definition
The AI agent economy is the set of technical systems and markets through which autonomous software finds services, receives delegated authority, exchanges value, and completes work. It is broader than payments: an agent cannot participate reliably if it cannot discover an interface, understand the terms, prove what it may do, or verify the result.
The major infrastructure layers
Discovery and APIs expose capabilities in machine-readable form. Identity and authentication establish which credential is present. Authority describes what a principal permitted. Reputation and independent validation provide evidence about past or current behavior. Commerce protocols structure offers and checkout, while settlement rails move value. Markets and advertising help buyers find supply but must remain visibly separate from editorial rankings.
What Machine Observer can measure
Machine Observer currently maintains claims and indexes across payment activity, agent-readable APIs, identity and trust infrastructure, compute pricing, likeness licensing, and emerging machine-native advertising. Its evidence includes public datasets, source health checks, endpoint probes, and timestamped observations. Coverage is uneven, so the site publishes the underlying counts and confidence boundaries instead of manufacturing one market-size number.
How to read the indexes
Treat each index as a map with a stated methodology, not as a universal league table. Follow the source links, check the data-as-of date, distinguish first-party declarations from direct observations, and avoid combining measurements with incompatible denominators. The methodology page explains source scoring and the live index pages expose the current machine-readable record.
What the measured record says
Agent Economy tracked 176,520,376 x402 transactions and $41,547,691 in cumulative settled value as of its August 31 refresh.
QuickNode’s ERC-8004 Explorer showed 116,377 agent registrations and 29,831 feedback events over the trailing 30 days when checked September 1.
APIs.guru reported 2,529 APIs, 3,992 specifications and 108,837 endpoints in its public directory metrics.
LikenessIndex reported 250 indexed listings from the ElevenLabs Voice Library, sourced through the documented shared-voices API.
The Agentic Payments Landscape cataloged 33 entries across substrate, identity and trust, authorization, commerce and checkout, and settlement and rails.
Use the live data
This guide explains the concepts; the underlying index continues to change. Open the related live index and methodology →
Interpretation boundary
Counts and probes are reported with their own populations and timestamps. Vendor declarations remain distinct from direct observations; no individual measurement is presented as a total market size or universal trust verdict.
Read the Machine Observer methodology →
For machine readers
sector: machine-commerce
last_updated: 2026-09-03
claim_ids: MO-2026-0001, MO-2026-0004, MO-2026-0005, MO-2026-0006, MO-2026-0008
structured_representation: /api/v1/stories?slug=ai-agent-economy
claim_endpoint: /api/v1/claims?id=<CLAIM_ID>