Agent discovery
Machine-readable entry points — llms.txt, markdown negotiation, well-known catalogs, and DNS-AID.
Being usable by AI agents is part of the product. Everything below is live on the apex domain.
llms.txt
/llms.txt is the site overview for agents: what the tools do, when to reach for them, and how to call them (API → MCP → prefilled links).
Markdown negotiation
Every page returns a markdown representation when requested with
Accept: text/markdown:
curl -H "Accept: text/markdown" https://essentials.sh/qrDocs pages additionally have stable markdown twins at /docs/<slug>.md.
Well-known catalogs
| Path | Format |
|---|---|
/.well-known/api-catalog | RFC 9727 linkset (application/linkset+json) |
/.well-known/ai-catalog.json | ARD capability manifest |
/.well-known/agent-skills/index.json | Agent Skills Discovery index (+ per-skill SKILL.md) |
/.well-known/mcp/server-card.json | MCP server card |
/openapi.json | OpenAPI 3.1 spec |
HTML responses also carry RFC 8288 Link headers pointing at the catalogs,
and 404s return a markdown body with recovery links for non-browser clients.
DNS-AID
ServiceMode SVCB records advertise the MCP endpoint in DNS, signed with DNSSEC:
_mcp._agents.essentials.sh SVCB 1 essentials.sh. alpn="h2" port=443 key65280="/mcp"
_index._agents.essentials.sh SVCB 1 essentials.sh. alpn="h2" port=443 key65280="/mcp"
_catalog._agents.essentials.sh TXT "url=https://essentials.sh/.well-known/ai-catalog.json"The shell, too
curl essentials.sh | shThe domain is literally a shell script — it prints the checklist and these entry points in your terminal.