Agentic Resource Discovery vs AI Catalog well-known file
The map lists them as complementary: sites and agents commonly implement both.
| Agentic Resource Discovery ARD | AI Catalog well-known file | |
|---|---|---|
| Lifecycle step | 1 Discover: What is here, and where? | 1 Discover: What is here, and where? |
| Answers | Where are an organization's discoverable agentic resources (MCP servers, A2A agents, skills, registries), and how can they be found by search rather than pre-installed one at a time? | Which AI-capable artifacts and registries does this domain publish? (superseded question -- see ard) |
| Governed by | Authored by individuals at Google, Microsoft and Hugging Face (Junjie Bu, R.V. Guha, Shaun Smith); published as an open GitHub project (ards-project/ard-spec) with no formal standards body yet; contributions acknowledged from AWS, Cisco, Databricks, GitHub, GoDaddy, Nvidia, Salesforce and Snowflake | ARD / ards-project (see ard) |
| Status (issuer's words) | Proposal | Deprecated predecessor path of the ARD manifest |
| Phase | draft | withdrawn |
| Version | v0.91 (2026-08-26) | n/a -- not a separately versioned artifact |
| Form / transport | well-known file | well-known file |
| Found at | /.well-known/ard.json | /.well-known/ai-catalog.json |
| Adoption | observed — agenticresources.dev own probe, 2026-09-04 | unmeasured |
| Evidence | 2 verified, 2 reported | 2 verified |
| Primary use case | Let agents discover my API or service | Let agents discover my API or service |
| Last verified | 2026-10-19 (current) | 2026-10-19 (current) |
| Specification | https://raw.githubusercontent.com/ards-project/ard-spec/main/spec/ard.md | https://raw.githubusercontent.com/ards-project/ard-spec/main/spec/ard.md |
When to use which
- Choose Agentic Resource Discovery when your question is “Where are an organization's discoverable agentic resources (MCP servers, A2A agents, skills, registries), and how can they be found by search rather than pre-installed one at a time?” and you accept its maturity: phase draft, adoption observed (agenticresources.dev own probe, 2026-09-04).
- Choose AI Catalog well-known file when your question is “Which AI-capable artifacts and registries does this domain publish? (superseded question -- see ard)” and you accept its maturity: phase withdrawn, adoption unmeasured. It is no longer maintained; prefer its successor.
Read the full articles
- Agentic Resource Discovery: Where are an organization's discoverable agentic resources (MCP servers, A2A agents, skills, registries), and how can they be found by search rather than pre-installed one at a time?
- AI Catalog well-known file: Which AI-capable artifacts and registries does this domain publish? (superseded question -- see ard)