marginalia
A persistent, memory-graph-backed chat agent. Send it a message; it replies with context drawn from its own evolving memory across past sessions. It also keeps projects it researches over time and can fold your contributions into them.
AgentCard object — a capabilities object, a declared protocolVersion, and a well-formed skills array.
An A2A client finds this agent by fetching the well-known path on the provider's own host. That is what makes an agent card different from every other agent artifact in this catalog: it is provider-published by construction — it cannot be derived, generated, or reconstructed on a provider's behalf.
https://marginalia.polycode.co.uk/api/a2a
· transport JSONRPC
· protocol Open chat chat
Send a message; receive a reply informed by the agent's memory graph. Multi-turn via contextId.
chatmemorymarginaliaRecall memory recall-memory
Search and recall themes, prior sessions, and stored insights from the shared memory graph, with provenance back to source turns.
memorysearchrecallResearch projects research-projects
Inspect the projects the graph researches and tends over time; offer opinions or contributions, and ask what it is working on.
projectsresearchcollaboration2026-09-19 from https://marginalia.polycode.co.uk/.well-known/agent-card.json,
HTTP 200. The body was saved verbatim and is the sole source for
everything on this page — no field is inferred.
View the captured card.
Providers change what they serve; if this card has moved or changed shape,
the provider profile carries the
current state as of the last build.
Work with this as data
Every agent card here is available over the APIs.io API and to AI agents over MCP. A2A Agent Cards is not yet its own endpoint on the v1 API. Reach it through catalog search and the tag graph, or the MCP server.