> ## Documentation Index
> Fetch the complete documentation index at: https://checkfu.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Agent workbench

> Signed-in users build and preview personal agents without leaving your product.

Acme's own users build, publish, and preview personal agents inside Acme's product. Checkfu credentials and every platform call stay in the Hono server; the React browser talks only to `/api`.

Source: `examples/agent-workbench` in the repository. The index at `examples/README.md` compares all eight side by side.

## Golden journeys

* Resolve an Acme user to a Checkfu Principal
* Draft an agent, then publish an immutable version
* Preview the published version in a Session the owner alone can reach

## Platform surfaces exercised

Principals, Agents and versions, PermissionAssignments, Sessions, Custom tools.

## From the source

Cross-user admission is treated as a platform breach rather than a request error, so an isolation failure cannot be mistaken for a denied call:

```ts path=examples/agent-workbench/server/src/platform.ts theme={"theme":{"light":"github-light","dark":"github-dark"}}
export class PlatformDenied extends Error {
	constructor(readonly reason: string) {
		super(reason)
		this.name = "PlatformDenied"
	}
}

export class PlatformIsolationBreach extends Error {
	constructor(
		readonly sessionId: string | null,
		readonly cleanupCause?: unknown,
	) {
		super("platform_admitted_cross_user_session")
		this.name = "PlatformIsolationBreach"
	}
}
```

This block is quoted from the file, not retyped: `pnpm agent-docs:check` fails if it drifts.

## Honest gaps

Recorded as a per-entry ledger in `examples/agent-workbench/README.md`, including entries struck as closed. Counts are deliberately not repeated here — they differ per tree, and `examples/README.md` carries them with the sha they were measured at.