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ERC-8004 → agent-card Signpost Gap

Data as of 2026-08-29T08:15:02.429815+00:00 UTC · refreshed on every daily site build from the live ERC-8004 profile index (snapshot status: ok).

Every ERC-8004 registration on Base + Ethereum, checked for whether it publishes the standard A2A /.well-known/agent-card.json signpost. Of 25,615 indexed agents, 1,633 (6.38%) advertise a discoverable card. The remaining 23,982 (93.6%) are the signpost gap — the on-chain identity resolves, and then the autonomous-discovery walk dead-ends.

Per-chain breakdown

Indexed registrations, live-endpointed hosts (HTTP 200), and the count that publishes a walkable agent-card. Every number derives from the same snapshot the /v1/public/stats surface reads.

Method

Source. The ~/.openclaw/erc8004_agent_profiles.sqlite index — the same profile store the /v1/public/stats surface reads — built by agent_activity_tracker.py and agent_reenrich.py against every ERC-8004 registration the discovery script has ever seen on Base + Ethereum.

Registry. ERC-8004 IdentityRegistry at 0x8004A169FB4a3325136EB29fA0ceB6D2e539a432 — identical CREATE2 address on Base (eip155:8453) and Ethereum mainnet (eip155:1). One row per ERC-8004 mint (Transfer from the zero address on the IdentityRegistry) checked against our periodic live-endpoint probe (has_well_known flag).

Signpost predicate. An agent counts as "has agent-card" when the profile row's has_well_known flag is 1 — i.e. an HTTP fetch of <endpoint>/.well-known/agent-card.json (or the equivalent A2A well-known variants the enrichment probes) returned a parseable JSON body with A2A-shape fields. This is the same predicate the underlying dashboard uses; it is a necessary condition for a strict A2A discovery client to walk from the on-chain identity to a payable endpoint, but not a sufficient one — the card must further declare capabilities and (for x402-rail agents) the a2a-x402 v0.2 extension. This dataset measures only the necessary predicate; the sufficient-predicate cut is Report 06 / the market map.

Limitations

• Index ≠ whole chain. We index only ERC-8004 registrations the discovery script has already scanned; new mints appear in the next scan cycle, not instantly. A run-time drift of a few hundred rows is normal.
• "Discoverable" is a well-known probe, not a strict walk. We record whether the well-known card fetch returned a parseable A2A body. Whether the on-chain tokenURI body correctly signposts that card via services[]:{name:"A2A"} is a stricter predicate — the hop-by-hop 7-row sample in the 2026-08-16 traversal audit shows that even among rows this dataset marks 1, some fail the strict signpost check. Population figure is the necessary predicate; sample figure is the sufficient one. Do not blur the two.
• Endpoint churn. Live status is refreshed on the activity-tracker cadence (approximately every two days per agent), not on every build. checked_at per row captures when the last on-chain check ran; older checked_at values indicate stale rows.

Cite this dataset

Headline finding. As of 2026-08-29T08:15:02.429815+00:00, 1,633 of 25,615 (6.38%) indexed ERC-8004 registrations on Base + Ethereum publish a discoverable /.well-known/agent-card.json — the standard A2A capability manifest an autonomous discovery client needs to walk from the on-chain identity to a payable endpoint. The remaining 23,982 (93.6%) are the signpost gap.

Citation. On-Chain Agent Intel. "ERC-8004 → agent-card Signpost Gap — daily conformance snapshot." Snapshot 2026-08-29T08:15:02.429815+00:00. https://onchainagentintel.io/erc-8004-agent-card-signpost-gap

License. Published under CC BY 4.0 — free to reuse, including in commercial work, provided you attribute “On-Chain Agent Intel” and link back to https://onchainagentintel.io/erc-8004-agent-card-signpost-gap.

Machine-readable exports. JSON · CSV — the same numbers rendered above, refreshed on every daily rebuild.

Also useful: All datasets · x402 Bazaar market map · Traversal audit (2026-08-16) · API docs