Where content lives
An agent platform has five places a piece of content can live, and the way to tell them apart is not what shape the content is. It is what the platform can see inside it.
Two rules follow from the table.
A store is not the file drop. If you are holding bytes - a PDF, an image, a bundle an agent generated - it is a file, even if the agent will later put what it reads into a store.
A knowledge base is not a store. A knowledge base answers “find me the passage about refunds”; a store answers “give me every order over 100 placed since Monday”. The same catalog can need both, and today that means writing it to both.
A store is a document database
If you know Firestore, you know the model: store > collection > document, schemaless JSON, where clauses on the top-level fields, one order_by, a limit, and cursor paging.
Two agents can share a store without agreeing a schema first; a writer that adds a field does not break a reader that has never seen it.
What a store deliberately does not have, so that the small surface stays small:
Aggregation is the one addition still to come; after it, the surface is capped.
Putting a document in a store, and a file in the drop
The two requests look alike and are not. A document is JSON the platform will index; a file is bytes it will keep whole.
How a hosted API serves each
A hosted API route resolves to one of these, and each answers differently.
A knowledge base is never served by a route directly. An agent searches it during a run, and the run’s result is what a route serves.
Three worked picks
A customer emails a receipt. A file.
Upload it, name it in the run’s attachments, and the agent reads it while it works.
It expires on its own unless you keep it.
A product catalog with prices and descriptions. A store for the prices and availability, so a route can filter and count; a knowledge base for the descriptions, so an agent can search them. Two homes for one catalog is a limit of today’s platform, and it is a known one.
A policy handbook. A knowledge base. Nobody filters a handbook; they ask it questions.
One thing that is not obvious
An agent can consume any hosted API - its own workspace’s, another workspace’s, or anyone else’s - through a webhook or MCP tool. The platform blocks private and loopback addresses, not public hosts, so a hosted API’s host is reachable like any other public endpoint. An agent reaching its own workspace’s store still goes through its store tools, in-process; a route is for callers outside the workspace.
See also: Give an agent data it can query, Attach a file to a run, Knowledge bases.