What we tested
Probed live on 26 Sep 2026 against rubric v1.2. 1 of 5 checks passed. 3 unknown.
PROBE-VERIFIEDtier 2 of 3
✓MCP server card/.well-known/mcp/server-card.json · present; could not ask whether its server answers
not scored —Platform-suppliednot applicable — no MCP endpoint answered
not scored ✓Other agent files at well-known pathsagent-skills/index.json · oauth-authorization-server · oauth-protected-resource · http-message-signatures-directory · found: Agent Skills index, HTTP message signatures directory
not scored What an agent could do here
Read from the page’s own content, with the wording each was drawn from. Inference is kept separate from tested facts — an agent completing the action is tier 3.
UNVERIFIED
register“”https://beta.once.app/oauth/register
Context
597 sites in the index share the category music. 220 transactional sites share it.
How we grade
Three tiers. Every listing shows which one it has reached, and when. The rubric.
tier 1Declared
The site says agents are welcome in its robots.txt. A permission, not a capability.
tier 2Probe-verified
We fetched the site and tested each signal ourselves. Dated, repeatable, re-checked on a schedule.
tier 3Behaviourally verified
An agent completed the action end to end — booked, bought, submitted — and it worked.
Own this site?
1 check did not pass when we last looked: llms.txt. Each is a small, specific fix; the rubric says exactly what we look for.
Behavioural verification — an agent completing your booking, purchase or contact flow end to end, with the date published here — opens to a small founding cohort first. Leave an email to be in it.
Related verified sites
Nigel Ball MusicBritish rock blues musician Nigel Ball's portfolio site with biography, discography, 2026 tour dates, and contact information. Also operates the Rock Blues Agent Hub registry of artists, venues, and festivals.
music Lacuna MusicAI audio studio offering music generation from style and lyrics, audio editing, mastering, autotune, mashups, stem separation, MIDI tools, lyric writing, album cover generation, and ambient AI radio. Services include AI-generated songs, instrumentals, and visuals.
music Dan MurtaghMelbourne-based mixing, mastering, and production engineer offering remote and in-studio services, free interactive mixing tools including compressor settings, loudness targets, compression diagnostics, EQ charts, and tutorials.
music Didgeridoo MasterSpanish reference site about the didgeridoo, an Australian Aboriginal wind instrument: how to play it, its history, types, buying guides, and health benefits. Edited by E2D WEB & GROWTH SL, serving Spain.
music DigcrateAI-powered music research platform for DJs, producers, and crate diggers, aggregating data from 20+ music sources to provide artist profiles, track credits, influence maps, show prep, and music news.
music RecoupRecoup API platform for building record labels with endpoints for research, content creation, chat, artist analytics, social media, and platform management.
music RockskyDecentralized, open-source music scrobbling network on the AT Protocol for tracking music plays, managing metadata, and integrating with Jellyfin, Navidrome, Spotify, and other players.
music Meiji SamplerDocumentation site for Meiji Sampler, a terminal-based music sampler for building beats, recording loops, arranging scenes, chopping samples, MIDI mapping, mixing, and exporting tracks.
music Record generated from a live database query. Method: about the index.
How we found this site: probe discovery. This site didn’t declare agent access — we found it by checking the open web. Everything above was tested the same way, against the same rubric, on the date shown. How we choose what to check, and how to opt out →