---
description: "Application Remote assembly: selects typed Host capabilities and forwarded events for Client consumers."
kind: "package-reference"
---

# @deepseek-ai/dsh-api-remotes

English | [中文](README.zh.md)

## Summary

Two-sided BFF for Host Remote capabilities selected by this application. The Host entry owns the forwarded-event selection and registers its application event source with API Gateway; the Client entry imports generated `/remote` artifacts as runtime values, mounts each contribution through `ctx.remote.$mount()`, and re-exports their declaration merges. Client business packages depend on this facade rather than the Gateway implementation or individual Remote runtime entries.

## Table of Contents

- [Use this package](#use-this-package)
- [Forwarded Host events](#forwarded-host-events)
- [Build boundary](#build-boundary)
- [Model Experience](#model-experience)
- [Known Limitations and Deferred Work](#known-limitations-and-deferred-work)
- [Dev Note](#dev-note)

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<a id="use-this-package"></a>
## Use this package

[`@deepseek-ai/dsh-api-session-controller`](../session-controller/README.md) owns Agent and Session identity policy, including the Typert lookup resolvers used by other namespaces. This package only selects and mounts that generated Session contribution; it does not duplicate activation policy.

The Client assembly mounts Commands, credentials, settings, Goal, dynamic Cordis, file and Session references, read-only Host plugin inventory, message feedback, Session Controller, and Workspace Controller contributions. Cordis effect ownership withdraws every contribution when this assembly unloads, while `@deepseek-ai/dsh-api-gateway/client` owns descriptor validation, traced namespace Services, direct and scoped methods, invocation, streams, and cancellation. The Client entry consumes the shared `TypertClientRemote` interface through Cordis and does not import the concrete Gateway. It re-exports the Gateway Client face's declaration merges type-only, so a consumer reaching the forwarded-event vocabulary through this facade gains no runtime edge to the Gateway implementation.

This facade is also the front door for the wire type vocabulary a Client package names. It re-exports, type-only, the Remote failure vocabulary (`RemoteResult`, `RemoteFailure`, `RemoteErrorCode`, `RemoteErrorDetailsMap`), the Host facts (`RemoteHostFacts`), and each selected domain's client-safe payload types, so a Client feature package imports one specifier instead of reaching into `dsh-typert-protocol`, the Gateway, or an owner's Host entry. Two kinds of package deliberately skip this door: the api-layer packages this assembly itself selects — importing it back would close a dependency cycle — and their tests, which take the failure vocabulary from `dsh-typert-protocol` directly. A UI package's tests instead take the `RemoteError` constructor from [`dsh-client-test-runtime`](../../test-support/client-runtime/README.md).

This package owns no physical transport or Host service discovery. It projects the application selection into generated Remote contributions and an independent Host event source per Client; API Gateway owns endpoints, carriers, cancellation, and reconnection. Its Client face can be reused by Web or a future TUI that provides the same React-free `ctx.remote` contract.

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<a id="forwarded-host-events"></a>
## Forwarded Host events

`src/remote-events.ts` holds `API_REMOTE_FORWARDED_EVENTS`, the allowlist of Host Cordis events this application forwards without renaming, and therefore the legal key set of `ctx.remote.$on`; each entry also selects ordinary emission or Agent-scoped waterfall delivery. The type-only `src/types.ts` derives its selection face. Forwarding one more event requires one entry in that array: the type projection, consumer key face, and Host forwarding loop all derive from it.

The listener signature is not restated here. Each allowlisted event's Cordis `Events` declaration lives in its owner package's client-safe `./types` export, and both faces of this package pull those declarations in. The Host face additionally asserts every entry against `TypertForwardableEventEntry`: an `emit` entry must be a declared one-way event, while a `waterfall` entry must be a declared Agent-scoped waterfall whose final parameter is its same-result `next()` callback.

The Host entry registers an independent allowlist listener set and queue for each Client stream. It rejects non-JSON ordinary-event arguments before enqueueing. For a waterfall, it projects only the top-level Agent identity and JSON request fields; a Client result must also be lossless JSON, while `next()` delegates to the following Host listener. The source attaches all listeners synchronously before `ctx.typertGateway.registerRemoteEvents()` exposes Gateway's internal `$events` logical stream, so its first `ready` item proves that incremental delivery is active and carries the Host home for Client path display. Withdrawing the registration aborts active streams.

<a id="build-boundary"></a>
## Build boundary

Most repository packages belong to one TypeScript face: Host packages are registered in the root `tsconfig.host.json`, and Client packages in the root `tsconfig.client.json`. This package splits because its Host entry must participate in the Host Typert graph, while `src/client/index.ts` cannot compile until Host tsdown has generated the business packages' `/remote` declarations.

This package's root `tsconfig.json` is only a solution that references `tsconfig.host.json` and `tsconfig.client.json`. The Host aggregate and direct Host consumers reference the former, while the Client aggregate and direct Client consumers reference the latter; the package-root solution must not enter either aggregate's dependency graph. The two projects own disjoint source files and `.tsbuildinfo` files but share the `lib/types` output directory, with one deliberate exception: `src/remote-events.ts` and `src/types.ts` are listed in BOTH faces' `files`, because the forwarded-event allowlist is the single control point over what a consumer can receive, and the Host forwarding loop and the Client `ctx.remote.$on` key face must read one declaration rather than two that could drift.

That exception is not just a `files` entry. The root `tsconfig.base.json` maps `@deepseek-ai/dsh-api-remotes/types` to `src/types.ts` — the source plane, like every other workspace subpath and unlike the generated `/remote` artifacts, which have no `paths` entry and resolve through `exports` to built output. Both faces therefore admit the same allowlist and type projection into their own programs and emit byte-identical `remote-events` and `types` outputs into `lib/types`; the `.tsbuildinfo` files stay independent. No gate enforces the faces' source-file disjointness — `scripts/project-reference-faces.ts` only checks that a reference into a split project names the matching face — so this paragraph records why the double listing is intentional.

The package-local `clientBundle(..., { hostPhase: true })` makes Host tsdown bundle the Host entry and the later Client tsdown bundle only the browser entry. Ordinary Client plugins remain single Client projects and produce both their Node loader entry and browser bundle during Client tsdown; split only when the two source sets require different compiler faces.

<a id="model-experience"></a>
## Model Experience

None, as this BFF selects Remote application methods and forwarded events but registers nothing model-facing.

#### KV Cache effect

No direct effect; mounted Host capabilities own any model-visible behavior they trigger.

## Known Limitations and Deferred Work

<a id="known-limitations-and-deferred-work"></a>

- The capability set is fixed by explicit build-time value imports; the Client does not discover the Host's active Services or Remote definitions at runtime.
- Additional capabilities require an explicit `/remote` value import and mount in this assembly.
- Ordinary forwarded events are not replayed; state that requires reliable recovery needs an owner-provided query, cursor, or opening baseline.


<a id="dev-note"></a>
### Dev Note

<details>
<summary>Working context for maintainers — click to expand</summary>

None.

</details>
