Catalog

Here are the things you can plug into an agent, and the things Fountain plugs into.

Each entry has the same shape. Read one and you can skim the rest.

Choose an agent's parts

Catalog	An entry is	Count
Runtimes	One coding-agent CLI that a sandbox can run.	4
Skills	One SKILL.md that Fountain writes into the sandbox.	2 bundled, and any repo on GitHub.
MCP servers	One server that gives the runtime tools.	3 hosted, 10 verified remote, and any server you declare.

Start from a whole agent

Agents is the catalog of ready-to-apply manifests. One file holds an Environment, a Vault and an Agent, and one fountain apply -f reconciles all three. There is 1 entry, a Fountain contributor.

Elsewhere in these docs

Two catalogs are older than this section, and they keep their own pages for now.

Sandbox providers. Where a conversation's machine comes from. Sprites, E2B, Daytona, or a machine you own through fountain runner.

Services Fountain uses. What an operator configures. Mail, GitHub OAuth, Stripe, Sentry.

Plug into Fountain. What drives Fountain from outside. Editors, chat surfaces, plugin hosts, relays, and your own code.

Request an entry

If you want an entry that does not exist, open an issue. The entry template is standards/catalog-template.md in the repository.

For a remote MCP server, run mix run --no-start scripts/mcp-catalog-probe.exs <url> first. A green probe is the whole bar for the verified list. "Supported" as an opinion was the reason no such list existed for a year.