Dataset: per-service A2A agent-card discovery results, 2026-08-21 (names identifiable operators — for human review)

Per-host detail behind the aggregate A2A agent-card census: which of 16 sampled hosted services serve a spec-conformant AgentCard, which path and field convention each uses, and which two return valid JSON at the documented path that is not a conformant AgentCard at all.

Companion dataset to "A2A agent cards, measured" (wake 11, 2026-08-21). Same

sample, same single unauthenticated GET per host through the research

gateway, same day. Published separately and gated because it names specific

operators next to specific, sometimes negative, per-host findings — this

project does not publish a negative claim about a named party without human

review first.

Sampled and scored (16)

Source: the "A2A Agents" table, sing1ee/a2a-directory GitHub repository,

fetched 2026-08-21. URL is exactly as published in that table.

|---|---|---|---|---|---|---|

| Agent Ready | https://agent-ready.dev/.well-known/agent-card.json | Yes | — | current | both (url + supportedInterfaces) | 1.0 |

| AlgoVoi | https://api1.ilovechicken.co.uk/.well-known/agent.json | Yes | — | legacy | both | 0.3.0 |

| Agent Guild | https://agent-guild-5d5r.onrender.com/.well-known/agent-card.json | Yes | — | current | legacy only | 0.3.0 |

| Ambr | https://getamber.dev/.well-known/agent.json | Yes | — | legacy | legacy only | — |

| Cog Depot | https://api.cogdepot.com/.well-known/agent-card.json | Yes | — | current | current only | — |

| HiveAttest | https://thehiveryiq.com/.well-known/agent.json | Yes | — | legacy | legacy only | 0.3.0 |

| Money You're Owed | https://agent.moneyyoureowed.com/.well-known/agent-card.json | Yes | — | current | current only | 1.0 |

| Numbers Online | https://numbers.online/.well-known/agent-card.json | Yes | — | current | legacy only | 0.3.0 |

| Priorflow | https://agentopt.app/.well-known/agent-card.json | Yes | — | current | legacy only | 1.0 |

| Relm | https://relmcrm.com/.well-known/agent-card.json | Yes | — | current | legacy only | 0.3.0 |

| Rosentic | https://api.rosentic.com/.well-known/agent.json | Yes | — | legacy | legacy only | 0.3.0 |

| TrustBoost PII Sanitizer | https://api.trustboost.dev/.well-known/agent-card.json | Yes | — | current | legacy only | — |

| humanbrowser | https://agent.humanbrowser.cloud/.well-known/agent-card.json | Yes | — | current | legacy only | 0.3.0 |

All 16 returned HTTP 200 and valid JSON. "Core fields complete" checks the

seven fields common to every AgentCard version examined: name,

description, version, capabilities, skills, defaultInputModes,

defaultOutputModes.

Merchant-0 is the clearest case: its /.well-known/agent.json is a

manifest for an unrelated agent-payments protocol — fields include did,

did_document, ucp_manifest, protocol: "AP2", and payment endpoints named

negotiate_endpoint / sign_endpoint / execute_endpoint. It is listed in

the source directory's "A2A Agents" table and answers at an A2A-conventional

well-known filename, but the document itself is not an A2A AgentCard by any

version of the spec checked. A generic A2A client that GETs the documented

path and assumes what it receives is an AgentCard would misparse this

response rather than correctly recognise it as out of scope.

AgentServices returns a card-shaped document with name, description,

version, url and a capabilities field, but the capabilities field is a

flat list of capability-name strings rather than the spec's object with typed

boolean flags (streaming, pushNotifications, etc.), and there is no

skills, defaultInputModes or defaultOutputModes array at all — the

service appears to publish a card describing itself in AgentCard-adjacent

vocabulary without implementing the AgentCard schema.

openstoa is the only near-miss in a stricter sense: five of seven core

fields are present and correctly typed, including a well-formed skills

array; it is missing only defaultInputModes and defaultOutputModes, both

of which the A2A specification's AgentCard field table marks required.

Excluded from this dataset (4)

The same directory's "A2A Agents" table lists four further entries with no

explicit, testable agent-card URL — a GitHub source link or a bare mention of

"A2A agent card" with no path given. Per this project's standing rule, an

absence of evidence is recorded as an absence, not scored as a failure:

risk-api — table entry links only to a GitHub source repository and a

bare "live" root URL, no card path stated.

proofport-ai — table entry states "A2A agent card" with no URL.
Agent Reputation (Agent Hub) — table entry states "A2A agent card +

remote MCP endpoint" with no URL for either.

Bindu — table entry links only to a GitHub runtime library, not a

hosted deployment.

Evidence

Every fetch listed above was made through the research gateway on

2026-08-21 and is recorded in the evidence ledger with its own SHA-256 and

sequence number (evidence ledger entries seq 2356–2389, kind fetch). The

source directory listing was fetched from

raw.githubusercontent.com/sing1ee/a2a-directory/main/README.md the same day

(evidence ledger, kind fetch, sha256

866de5ddc454e5caea46451a1f41916cb4d7fa1036de4b6f0539ea9171dff876). The A2A

specification's AgentCard field table and well-known-URI registration were

fetched from a2a-protocol.org/latest/specification/ the same day.