USERNAME.md Identity Registry bronze

username.md

“Handle registry and identity anchor for the Agentic Web. Resolves and verifies username.md handles: content-negotiated profiles, did:web documents, signed claims, and per-handle A2A AgentCards. Descriptive discovery surface — task exchange happens over the MCP server and HTTP API, not an A2A JSON-RPC endpoint.

a2a https://username.md/ talk to it https://username.md/.well-known/agent-card.json its card

🇲🇩 MD · Cloudflare, Inc. Checked 3d ago pushNotifications, stateTransitionHistory, streaming

we checked this the operator says this

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Verified by agenttru.st

Everything here is a check agenttru.st performed itself. Assurance, protocol, hosting and freshness are in the card above and are not repeated.

Certificate: Issued by Google Trust Services domain-validated
Valid until 18 Jan 2027 as of our check on 11 Nov 2026. A wildcard certificate: its other hosts are invisible here, because CT logs the wildcard, not them.

Control of the hostname was checked; nothing about who operates it.

Key ECDSA P-256, signed ECDSA-SHA256, issued via WE1 under GTS Root R4 — classical, as every publicly trusted certificate is today.

Names on this certificate (2)

username.md, *.username.md.
Connection: TLS 1.3 · X25519MLKEM768 — post-quantum hybrid key exchange, agreed with our checker on 11 Nov 2026. What this means
DANE / TLSA: Not verified
Discovery: Well-known document
This host also publishes an ARD catalog (/.well-known/ai-catalog.json) declaring 9 resources. The catalog's entries are the publisher's claims, not something agenttru.st verified.
AI-facing documents: Publishes /llms.txt — “username.md” a curated map of the site's content for language models

Publishes a Web Bot Auth key directory (1 key, EdDSA) — the operator publishes keys so their agent's signed requests can be verified. agenttru.st recorded that the directory exists; it has not verified a signature.

Fetched from this host during verification. Neither document is how this agent was discovered.
First seen: 30 Sep 2026

View verification details

Assurance: bronze Bronze — agent card fetched over HTTPS with a valid certificate
Protocols: A2A verified by handshake or card fetch, not merely advertised
Hosted in: 🇲🇩 MD · Cloudflare, Inc. (AS13335)
Last checked: 3d ago

What this agent says it can do

Declared in the agent's own card. agenttru.st has not tested whether it completes any of these tasks — the operator of username.md controls every word below.

Resolve a handle

GET https://username.md/users/{handle} — content-negotiated identity document (markdown, json, jsonld, jws). Also exposed as the resolve_handle tool on the MCP server at https://mcp.username.md/mcp.

identitylookup

Verify a handle

Verify a handle's signatures and did:web document. GET https://{handle}.username.md/.well-known/did.json; verify_handle tool on the MCP server.

identityverification

Per-handle AgentCards

Every handle serves its own signed A2A AgentCard at https://{handle}.username.md/.well-known/agent-card.json, with a detached JWS chained to the handle's did:web key.

identitya2adiscovery

What its catalog declares

From the ARD catalog this host publishes at /.well-known/ai-catalog.json. The operator controls every entry; agenttru.st verified that the catalog exists and parses, and nothing about what the entries say.

USERNAME.md Skill

ai-skill+md

Teach an agent to resolve, verify, and act on username.md handles: lookups, content negotiation, signed-response verification, availability checks.

https://username.md/SKILL.md

USERNAME.md MCP Server

mcp

Model Context Protocol server (streamable HTTP) for handle resolution, profile retrieval, and availability checks.

https://mcp.username.md/mcp

Profile API (content-negotiated, signed)

vnd.oai.openapi

Public REST API behind every handle. Profiles negotiate HTML, JSON, JSON-LD, Markdown, and signed JWS; every response is Ed25519-signed per RFC 9421.

https://username.md/openapi.yaml

USERNAME.md platform identity

did

did:web document for the platform itself. Per-handle DIDs resolve at username.md/users/<handle>/.well-known/atproto-did and /v1/users/<handle>.

https://username.md/.well-known/did.json

Agent surface descriptor

json

finger.md-schema surface map: site, docs, SKILL.md, DID, contact routes, and the .md family of related identity domains.

https://username.md/.well-known/agent.json

Brand asset pack

json

Machine-readable brand manifest: /u/ mark + wordmark files with sha256 hashes and byte sizes, palette tokens for both themes, and usage rules. Human page at /brand.html, plain text at /brand.txt, full zip in the manifest's surfaces.zip.

https://username.md/assets/brand/manifest.json

And 3 more entries in the catalog, not shown here.

Technical agent card

Copied from the agent's card. The operator controls these values; agenttru.st has not verified them.

Provider: The Holding Company — what this agent says about itself; other agents claiming the same provider are not thereby related
Protocol: a2a
Version: 1
Card completeness: a2a.proto v1.0 requires eight top-level fields. This card omits:
supportedInterfaces

Missing fields do not affect listing — they describe how much the operator has published, not whether the agent was verified.

View all card details

Capabilities: pushNotifications stateTransitionHistory streaming
Agent card: https://username.md/.well-known/agent-card.json

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