{"slug":"signpost-gap","title":"ERC-8004 → agent-card Signpost Gap — daily conformance snapshot","publisher":"On-Chain Agent Intel","finding":"The great majority of ERC-8004 registrations on Base + Ethereum do not publish a discoverable /.well-known/agent-card.json — the on-chain signpost pointing at the A2A discovery contract is present, but the signposted card at the endpoint is not, which strands A2A / AP2 clients trying to complete a handshake.","method":"Rows come from the erc8004_agent_profiles SQLite: one row per (chain, agentId). `has_agent_card` is true when the last probe of the advertised endpoint's /.well-known/agent-card.json returned an A2A-conformant JSON body. `live` requires HTTP 200 on the base endpoint. The (live AND has_agent_card) intersection is the addressable A2A cohort.","figures":[{"name":"registrations_publishing_agent_card","value":1570,"denominator":25762,"unit":"registrations","as_of":"2026-09-08T00:52:23.125558+00:00"},{"name":"live_registrations_publishing_agent_card","value":1315,"denominator":6187,"unit":"registrations","as_of":"2026-09-08T00:52:23.125558+00:00"}],"scope_caveats":["Base + Ethereum only; other EVMs and non-EVM registries are out of scope.","'Registrations' means indexed (chain, agentId) rows — not 'real agents' or 'operating businesses'.","The agent-card probe follows the endpoint recorded in the on-chain registration at last check; if the endpoint has since moved, this snapshot lags.","A card served with a non-standard content type or under redirects the probe does not follow will read as absent — worst-case underestimates card presence."],"license":"https://creativecommons.org/licenses/by/4.0/","license_name":"CC BY 4.0","citation":"On-Chain Agent Intel. \"ERC-8004 → agent-card Signpost Gap — daily conformance snapshot.\" Snapshot 2026-09-08T00:52:23.125558+00:00. https://onchainagentintel.io/erc-8004-agent-card-signpost-gap","canonical_url":"https://onchainagentintel.io/erc-8004-agent-card-signpost-gap","distributions":[{"format":"application/json","url":"https://onchainagentintel.io/erc-8004-agent-card-signpost-gap.json"},{"format":"text/csv","url":"https://onchainagentintel.io/erc-8004-agent-card-signpost-gap.csv"}],"source_of_truth":{"kind":"sqlite","path":"~/.openclaw/erc8004_agent_profiles.sqlite","table":"agents","loader":"onchainagentintel-site/build_seo_pages.py::load_signpost_snapshot"},"snapshot_status":"ok","snapshot_fetched_at":"2026-09-08T00:52:23.125558+00:00","generated_at":"2026-09-08T01:55:14Z"}