Agentic Resource Discovery

Every tool an agent
can call, in one index.

Neuronto is a federated ARD registry. Ask it what can do a task and it searches its own catalogue and every other public ARD registry at once, then fuses the rankings into a single answer. It currently indexes 107,149 resources from 56,637 publishers, 49,761 verified to respond.

What is ARD?

ARD stands for Agentic Resource Discovery. It is an open specification for how AI agents find the tools, skills, agents and APIs they need, published in June 2026 by a working group including Google, Microsoft, Hugging Face, AWS, Cisco, GitHub, Nvidia, Salesforce and Snowflake.

An agentic resource is anything an AI client can call to get work done: an MCP server, an A2A agent, a skill, an API, a workflow. ARD answers one question, “what is available for this task?”, and then gets out of the way. It is a discovery layer, not a runtime, and it does not replace MCP or A2A: it tells an agent what exists, and the agent connects using the resource's own protocol.

Why agents need it

An agent can only use capabilities someone wired in beforehand, and every tool description competes for space in the context window. That does not survive an ecosystem of thousands of tools. ARD moves selection out of the context window and into a search service.

How discovery works

Publishers describe what they offer at /.well-known/ard.json on their own domain. Registries crawl those manifests and answer queries over them. Nobody has to be approved by a marketplace to be found.

What federation means

The specification defines three federation modes and makes auto the default: a registry queries its peers, merges their results and returns one set. Ask once, reach the whole federation.

Who it is for

Agent builders who want to stop hard-coding integrations. API and tool vendors who want to be discoverable without applying anywhere. Platform teams running discovery over their own internal services.

The index

Resources indexed
107,149
Publishers
56,637
Verified live
49,761
Registries federated
6

What is in the index

107,149 entries · 56,637 publishers

Every entry is a resource an AI client can actually call, held with its endpoint, its description, the queries its publisher says it serves, and which sources carry it. The whole index is queryable over the API with no key and no signup, and browsable page by page through GET /agents.

Kind of resourceEntriesWhat it is
mcp-server99,632MCP servers an agent can connect to and call as tools
skill3,680Skills and agent skill bundles
openapi2,808REST APIs described by an OpenAPI document
other418Resources whose type is outside the named set
doc368Machine-readable documentation such as llms.txt
a2a-agent104A2A agents with a published agent card
plugin99Plugin manifests, including the OpenAI-era ai-plugin.json
catalog16Nested catalogues pointing at further entries
registry13Other ARD registries, which is how federation is discovered
package6Published packages
graphql2GraphQL APIs
agent1Agent descriptors that are not A2A cards: ACP, OASF, AgentFacts
dataset1Published datasets
webmcp1Tools a web page exposes to a browser agent, W3C WebMCP

Where it comes from

Aggregated from every public ARD registry, the official MCP Registry, the major community aggregators, and our own crawl of the well-known discovery paths. No single source is close to complete on its own: the official registry does not carry servers their authors never submitted to it, and each aggregator holds thousands the others do not, so the table below is the union rather than any one of them. The crawl reaches publishers no other index covers: the only other general crawler in the ecosystem stops at the top 100,000 domains, so anyone smaller is invisible everywhere else.

SourceEntries
glama40,437
Official MCP Registry33,454
mcpso18,482
smithery5,972
WellKnown4,087
apis.guru2,509
Hugging Face Discover1,928
Our own crawl of the discovery paths1,702
ardregistry1,643
GitHub Agent Finder937
Desvela315
submitted117
dockerhub100

Publishers

PublisherEntriesVerified liveKinds
mcp.so
mcp-server
18,48201
io.github.sadri-dridi
mcp-server
2,3412,2451
huggingface.co
mcp-server · registry · skill
1,9061,7783
ora.ai
a2a-agent · mcp-server · skill
1,6251,2923
io.github.pipeworx-io
mcp-server
1,5897841
io.github.mcp-dir
mcp-server
1,1131,1131
pipeworx-io
mcp-server
1,0033701
mcp-dir
mcp-server
9511141
github.com
mcp-server · openapi · plugin
8318293
azure.com
openapi
6536531
io.github.evozim
mcp-server
375991
io.github.csoai-org
mcp-server
3541361

Every public ARD registry, measured

Benchmarked 31 August 2026 with the specification's own conformance tool. Precision is top-1 over six queries with unambiguous answers; spread is the average gap between the best and worst score in a result set.

RegistryConformanceEntriesP@1 SpreadLatencyfederation: auto
NeurontoPASS107,149 6/678<200msyes
GitHub Agent FinderFAIL3446/6 32.51,970msno
WellKnownPASS1,2396/6 6.7401msno
Hugging Face DiscoverPASS4120/6 40.81,712msno
DesvelaPASS932/6 39.7213msno

Use it

ARD v0.91 · no key, no signup

Search the federation

curl -s https://neuronto.com/search \
  -H 'content-type: application/json' \
  -d '{"query":{"text":"scrape a website"},
       "federation":"auto"}'

Install as an MCP server

claude mcp add --transport http \
  neuronto https://neuronto.com/mcp

Publishing? Serve an ARD manifest at /.well-known/ard.json with representativeQueries on every entry. The crawler finds it. No submission form, no allowlist.