# Typert 远程调用

[English](typert.md) | 中文

以下类型由生成的 Remote 产物、Host Gateway 与消费方 API assembly 共用。[Typert Gateway Agent Note](../../.agents/notes/implemented/architecture/2026-08-02-typert-remote-method-calls.zh.md) 负责架构与传输决策；本页记录 [`dsh-typert-protocol`](../../packages/typert/protocol/src/types.ts) 和 [`dsh-api-gateway`](../../packages/api/gateway/src/types.ts) 中公共约定的字面定义。

## Lookup 与上下文声明

业务对象包通过声明合并扩展两个空 map。lookup 将一种 Host 对象类型与其 wire identity 关联；上下文声明将一种作用域上下文类别与其 wire identity 关联。生成的 descriptor 引用这些 key，运行时提供方则提供活对象解析行为。

```ts type-equiv
/** Merge-extensible Host object lookup declarations. */
interface TypertLookupMap {}
```

```ts type-equiv
/** Merge-extensible scoped Context declarations. */
interface TypertContextMap {}
```

lookup 的 resolver 卸载后，注册表仍会保留其 wire 声明。因此 SRC 发现过程会继续把该参数归类为 lookup，并因不可用而失败，而不会把 wire 值当作普通业务对象接受。

```ts type-equiv
/** Stable wire declaration retained after a lookup provider unloads. */
interface TypertLookupDefinition {
  /** Merge-declared lookup key. */
  readonly key: string
  /** Source parameter name recognized by the SRC weak parser. */
  readonly parameter: string
  /** Wire field replacing the Host object parameter. */
  readonly wire: string
  /** Canonical Host type symbol used by strict generation. */
  readonly hostTypeSymbol: string
  /** Canonical wire type symbol used by strict generation. */
  readonly wireTypeSymbol: string
}
```

## 调用 descriptor

`InvocationDescriptor` 是本地反射信息，不是 wire message。Host 与消费方构建会生成彼此对应的 descriptor；请求只发送 endpoint 与具名 `args`。strict codec 携带生成的 schema factory，SRC codec 则在不恢复结构类型的前提下强制要求 JSON 安全值。取消通过带外 carrier signal 表达：它在业务参数之后注入，绝不进入 `args`。

```ts type-equiv
/** Codec attached to one invocation parameter or result. */
type TypertCodec =
  | {
    readonly mode: 'strict'
    readonly typeSymbol: string
    /** Materialize and return the process-realm schema on first boundary use. */
    readonly create: () => TypertSchema
  }
  | {
    readonly mode: 'src-json'
  }
```

```ts type-equiv
/** One ordered business parameter in a Remote invocation. */
interface InvocationParameterDescriptor {
  /** Source-level parameter name. */
  readonly name: string
  /** Required key in the wire `args` object. */
  readonly wire: string
  /** Whether the value is JSON or requires a registered Host lookup. */
  readonly source: 'json' | 'lookup'
  /** Lookup key when `source` is `lookup`. */
  readonly lookup?: string
  /** Boundary codec for the wire representation. */
  readonly codec: TypertCodec
  /** Missing wire fields decode to `undefined` only for an explicitly declared `T | undefined`. */
  readonly acceptsUndefined?: true
}
```

```ts type-equiv
/** Carrier-independent description of one exported method invocation. */
interface InvocationDescriptor {
  /** Globally stable generated identity. */
  readonly id: string
  /** Cordis service key owning the method. */
  readonly service: string
  /** Wire namespace, defaulting to the service key. */
  readonly namespace: string
  /** Public instance method name. */
  readonly method: string
  /** Service member invoked when the exported method name is an alias. */
  readonly implementation?: string
  /** Absent for unary calls; stream calls deliver every yielded item as the Host produced it. */
  readonly mode?: 'stream'
  /** Receiver selection mode. */
  readonly invocation:
    | { readonly kind: 'direct' }
    | {
      readonly kind: 'context'
      readonly context: string
      readonly wire: string
      readonly codec: TypertCodec
    }
  /** Optional consuming-Context projection for one direct lookup parameter. */
  readonly scope?: {
    /** Context kind whose Client adapter supplies the identity. */
    readonly context: string
    /** Lookup parameter wire field replaced by the Context identity. */
    readonly wire: string
  }
  /** Ordered business parameters. */
  readonly parameters: readonly InvocationParameterDescriptor[]
  /**
   * Client-to-Host items of the same logical stream, generated from the `In`
   * type argument of the method's `RemoteStream<Out, In>` return type; absent
   * when `In` is `never`. The method reads the items through
   * `RemoteInvocation.uplink()`, so nothing enters the parameter list.
   */
  readonly uplink?: {
    /** Codec validating every uplink item before `uplink()` delivers it. */
    readonly codec: TypertCodec
  }
  /** Transport cancellation injected after business parameters instead of entering wire args. */
  readonly cancellation?: {
    /** Reserved final Host method parameter. */
    readonly parameter: 'signal'
  }
  /** Codec for the unary result or each yielded stream item. */
  readonly result: TypertCodec
  /** Source declaration used only for diagnostics. */
  readonly sourceLocation?: InvocationSourceLocation
}
```

Host 别名 `RemoteStream<Out, In>` 同时命名一条流的两个方向，接收方法通过 `this.ctx.invocation` 读取本次调用的上下文：

```ts type-equiv
/**
 * One Remote stream as a Host method returns it: the items it yields to the
 * Client, iterated as a plain `AsyncIterable<Out>`. `In` is the type of the
 * items the Client may send back on the same logical stream, read through
 * `RemoteInvocation.uplink()`; it is carried only as a type-level marker. The
 * default `never` declares a method that reads none, and its descriptor
 * carries no uplink codec. A generated Client stream method returns the same
 * stream as a `RemoteStreamHandle<Out, In>`.
 * @template Out - item type the Host method yields.
 * @template In - item type the Client may send; `never` when the method reads none.
 */
type RemoteStream<Out, In = never> = AsyncIterable<Out> & { readonly [STREAM_UPLINK]?: In }
```

```ts type-equiv
/**
 * One open Remote stream as the Client holds it: the downlink items as an
 * `AsyncIterable`, plus the uplink and cancellation of the same logical
 * stream. A generated Client stream method returns it, and calling that
 * method opens the stream: a holder that neither iterates nor disposes the
 * handle keeps the Host stream alive. A handle stands for one generation:
 * when the carrier is lost, iteration fails with the carrier error and the
 * handle is finished.
 * @template Out - item type the Host method yields.
 * @template In - item type the Client may send; `never` when the method reads none.
 */
interface RemoteStreamHandle<Out, In> extends AsyncIterable<Out> {
  /**
   * Send one uplink item. Items sent before the stream has opened are queued
   * and sent once the `open` frame is on the wire. A top-level `undefined`
   * travels as an `item` frame without `value`.
   * @param item - item the Host validates against the method's uplink codec.
   * @throws {Error} when the item is not a lossless JSON value, when `end()`
   * was called, or once the stream has terminated.
   */
  send(item: In): void
  /** Half-close the uplink: the Host's `uplink()` iteration ends. Idempotent; ignored after termination. */
  end(): void
  /**
   * Cancel the logical stream: send `cancel` unless a terminal frame has
   * arrived, and end the downlink iterator quietly. Breaking out of
   * `for await` early does the same.
   */
  dispose(): void
}
```

```ts type-equiv
/**
 * One Peer's session on this Host. Connection owns it: `ctx` is the Cordis
 * scope that owns connection-lifetime registrations and is disposed with the
 * Peer. Who the Peer is and what it may do are not recorded here.
 */
interface PeerScope {
  readonly id: PeerId
  readonly ctx: Context
  /**
   * Tear down every registration made through `ctx`.
   * @returns settles once the scope has quiesced; racing calls share one completion.
   */
  dispose(): Promise<void>
}
```

```ts type-equiv
/**
 * The context of one Remote call, reachable inside the receiving method as
 * `this.ctx.invocation`. The Gateway derives the receiver from a Context that
 * carries it, so no parameter is injected and nothing crosses the wire.
 */
interface RemoteInvocation {
  readonly request: {
    readonly namespace: string
    readonly method: string
    readonly args: Readonly<Record<string, unknown>>
  }
  /** Cordis service key of the receiving Service. */
  readonly service: string
  /** Peer the call speaks for; an in-process carrier speaks for the operator. */
  readonly peer: PeerScope
  /** Carrier cancellation: Client cancel, socket close, or an uplink failure. */
  readonly signal: AbortSignal
  /**
   * The Client's uplink items for this call. Available once; a second call
   * throws. With an uplink codec on the descriptor every item is decoded to
   * `In`; without one items arrive as `unknown` after a JSON-safety check.
   * Iteration ends when the Client ends its uplink; when the method finishes
   * its downlink the Gateway calls the iterator's `return()` and unread items
   * are dropped. `In` is the caller's assertion: the runtime decodes by the
   * descriptor and does not cross-check it.
   * @template In - item type the caller reads; the descriptor codec decides what arrives.
   * @returns the single-consumer uplink iterable.
   */
  uplink<In = unknown>(): AsyncIterable<In>
}
```

## Typert 注册表

`ctx.typert` 分开保存当前环境的 descriptor、显式选择的 Remote contribution、lookup 提供方与作用域上下文提供方。lookup 提供方拥有稳定 wire 声明和默认 resolver；Host 组合可以为同一个 key 配置 effect-scoped 同步或异步 resolver，配置卸载后恢复默认策略。各项注册都是由 Cordis 持有的 effect，并返回可等待的 disposer。

```ts type-equiv
/** Minimal Typert runtime consumed through dependency inversion. */
interface TypertRegistryContract {
  readonly local: TypertLocalRegistry
  readonly remotes: TypertRemoteRegistry
  readonly lookups: TypertLookupRegistry
  readonly contexts: TypertContextRegistry
}
```

生成的消费方声明会把 direct namespace 合并到 `TypertClientRemote` 继承的 map 中。

```ts type-equiv
/** Merge-extensible direct namespace surface generated for Client Remote services. */
interface TypertRemoteNamespaceMap {}
```

## Host Gateway

Connection 会先解码 carrier envelope，再调用 `ctx.typertGateway`。请求将精确的具名 wire 字段与 carrier 的取消 signal 分开携带；基础设施与边界失败由 `TypertGatewayError` 承载，其 `gateway/*` 码就是普通的 `RemoteError` 码，因此 RPC 适配器会把每个经结构识别的 `RemoteError` 连同其 code 与 details 原样放行，只把无法识别的异常归并为 `gateway/internal`。

```ts type-equiv
/** One Remote method request after a carrier has decoded its envelope. */
interface InvokeRemoteRequest {
  /** Remote namespace selected by the generated descriptor. */
  readonly namespace: string
  /** Exported Service method name. */
  readonly method: string
  /** Named wire values; fields must exactly match the descriptor. */
  readonly args: Readonly<Record<string, unknown>>
  /**
   * Client uplink items of this logical stream, delivered to the method through
   * `invocation.uplink()`; absent means an immediately ended iterable.
   */
  readonly uplink?: AsyncIterable<unknown>
  /** Peer the call speaks for; absent means an in-process carrier, answered as the operator. */
  readonly peer?: PeerScope
  /** Carrier or direct-caller cancellation injected only into cancellation-aware methods. */
  readonly signal?: AbortSignal
}
```

```ts type-equiv
/** Stable infrastructure and boundary failures emitted before or after business execution. */
type TypertGatewayErrorCode =
  | 'gateway/ambiguous-endpoint'
  | 'gateway/arguments-invalid'
  | 'gateway/binding-invalid'
  | 'gateway/context-failed'
  | 'gateway/context-not-found'
  | 'gateway/context-unavailable'
  | 'gateway/definition-unavailable'
  | 'gateway/input-invalid'
  | 'gateway/invocation-unavailable'
  | 'gateway/lookup-failed'
  | 'gateway/lookup-not-found'
  | 'gateway/lookup-unavailable'
  | 'gateway/method-unavailable'
  | 'gateway/protocol'
  | 'gateway/provider-mismatch'
  | 'gateway/result-invalid'
  | 'gateway/service-unavailable'
  | 'gateway/signature-invalid'
  | 'gateway/uplink-overflow'
```

```ts type-equiv
/** Host dispatcher consumed by Connection adapters. */
interface TypertGateway {
  /** Carrier adapter shared by WebSocket and in-process transports. */
  readonly wireStream: TypertGatewayWireStream
  /**
   * Register the application-selected forwarded-event source.
   * @param source - stream factory installed by the Remote assembly.
   * @param host - stable Host facts included in each Client generation's opening frame.
   * @returns disposer removing this exact source and cancelling its active streams.
   */
  registerRemoteEvents(
    source: TypertRemoteEventSource,
    host: RemoteEventHostInfo,
  ): () => Promise<void>
  /**
   * Invoke one live Remote method without assuming a carrier or response envelope.
   * @param request - decoded endpoint and named wire arguments.
   * @returns the business result without output decoding.
   * @throws {@link TypertGatewayError} for dispatch, provider, or boundary failures; lookup-policy and business errors retain identity.
   */
  invoke(request: InvokeRemoteRequest): Promise<unknown>
  /**
   * Open one live stream Remote method without assuming a physical carrier.
   * @param request - decoded endpoint, named wire arguments, and the Client uplink when the carrier has one.
   * @returns a cancellation-aware iterable over the business results.
   */
  stream(request: InvokeRemoteRequest): Promise<AsyncIterable<unknown>>
}
```

## 消费方 Remote

`ctx.remote` 只暴露由已导入 `/remote` 产物贡献的 namespace。`$mount()` 会把生成的 descriptor 与具体方法作为一项由 fiber 持有的操作统一注册。每个 namespace 都是可追踪的 `remote.<namespace>` Cordis 子服务，其生命周期覆盖已挂载的方法；JavaScript Proxy 与 Host 业务服务类型都不会进入消费方。

```ts type-equiv
/** Client Remote capability implemented by the Gateway and consumed by Remote assemblies. */
interface TypertClientRemote extends TypertRemoteNamespaceMap {
  /**
   * Mount one generated Host-for-Client contribution in the caller's fiber.
   * @param contribution - explicitly selected Remote package artifact.
   * @returns disposer after namespace services and concrete methods are ready.
   */
  $mount(contribution: TypertRemoteContribution): Promise<TypertDisposer>
  /**
   * Subscribe to one forwarded Host event. Notifications run in registration
   * order and isolate failures; scoped waterfalls return, delegate through
   * `next()`, or reject the Host dispatch.
   * @template Event - forwarded event name selected by the Host assembly.
   * @param event - forwarded Host event name, unchanged on the wire.
   * @param listener - receives the Client projection of the Cordis `Events` declaration.
   * @returns disposer owned by the calling fiber.
   */
  $on<Event extends TypertRemoteEvent>(event: Event, listener: TypertClientEventListener<Event>): () => void
}
```

<!-- BEGIN GENERATED cordis-surface (gen-cordis-catalog.ts) — do not edit between markers -->

<a id="cordis-surface"></a>

## Cordis API

Generated from source by `scripts/gen-cordis-catalog.ts` (verified fresh by `pnpm run verify-cordis-catalog` in doc-sync; regenerate with `pnpm run gen-cordis-catalog`) — the language sides differ only in locale-specific paired document paths. Signature blocks use a `ts cordis-catalog` fence and keep the original source JSDoc; dispatch modes are defined in the [primer](../cordis-primer.zh.md#dispatch-modes), and the framework-inherited `ctx` API lives in [cordis-api/inherited.md](../cordis-api/inherited.md).

<a id="ctxtypert--typertregistry"></a>

### `ctx.typert` — `TypertRegistry`

Registry of generated schemas, package reflection, invocations, and Remote dependency providers.

```ts cordis-catalog
/**
 * Register one generated contribution atomically for the calling fiber.
 * Duplicate package-face identities, schemas, invocation ids, or endpoints
 * reject the whole batch.
 * @param contribution - generated schemas, reflection, and Host invocations.
 * @returns the exact effect disposer that removes this contribution.
 */
register(contribution: TypertContribution): TypertDisposer

/**
 * Look up one schema by `<package>#<name>`.
 * @param key - global schema key.
 * @returns a record containing the cached schema, or `undefined` when absent.
 */
get(key: string): TypertSchemaRecord | undefined

/**
 * Resolve one required schema.
 * @param key - global schema key.
 * @returns a record containing the cached schema.
 * @throws when the key is malformed, the package face is absent, or the schema is not contributed.
 */
resolve(key: string): TypertSchemaRecord

/**
 * Enumerate live schemas in registration order.
 * @param filter - optional package and face restriction.
 * @returns matching records containing the cached schemas.
 */
list(filter: TypertSchemaFilter = {}): TypertSchemaRecord[]

/**
 * Look up generated reflection for one package face.
 * @param packageName - exact npm package name.
 * @param face - face to query; defaults to the host runtime.
 * @returns the live package record, or `undefined` when absent.
 */
getPackage(packageName: string, face: TypertFace = 'host'): TypertPackageRecord | undefined

/**
 * Enumerate generated package reflection in registration order.
 * @param filter - optional package and face restriction.
 * @returns matching package records.
 */
listPackages(filter: TypertPackageFilter = {}): TypertPackageRecord[]

/**
 * Project a live Zod schema to JSON Schema without caching the result.
 * @param key - global schema key.
 * @param params - Zod projection parameters.
 * @returns a fresh JSON Schema document.
 */
toJSONSchema(key: string, params?: z.core.ToJSONSchemaParams): z.core.JSONSchema.BaseSchema
```

Types: [TypertContribution](invariants.zh.md) · [TypertFace](invariants.zh.md) · [TypertPackageFilter](invariants.zh.md) · [TypertPackageRecord](invariants.zh.md) · [TypertSchemaFilter](invariants.zh.md) · [TypertSchemaRecord](invariants.zh.md)

Source: [`packages/typert/registry/src/service.ts`](../../packages/typert/registry/src/service.ts)

<a id="ctxtypertgateway--typertgatewayservice"></a>

### `ctx.typertGateway` — `TypertGatewayService`

Resolve strict generated definitions or conservative SRC markers against current Cordis Services and Typert providers.

```ts cordis-catalog
/**
 * Register the sole application-selected forwarded-event source.
 * @param source - stream factory installed by the Remote assembly.
 * @param host - stable Host facts included in each Client generation's opening frame.
 * @returns disposer removing this source and cancelling its active streams.
 */
registerRemoteEvents( source: TypertRemoteEventSource, host: RemoteEventHostInfo, ): () => Promise<void>

/**
 * Invoke one live Remote method through strict generated reflection or SRC markers.
 * @param request - decoded endpoint and exact named wire arguments.
 * @returns the business result without output decoding.
 * @throws {@link TypertGatewayError} for dispatch, provider, or boundary failures; lookup-policy and business errors retain identity.
 */
async invoke(request: InvokeRemoteRequest): Promise<unknown>

/**
 * Open one live stream Remote method without assuming a physical carrier.
 * @param request - decoded endpoint, named wire arguments, and the Client uplink when the carrier has one.
 * @returns a cancellation-aware iterable over the business results.
 */
async stream(request: InvokeRemoteRequest): Promise<AsyncIterable<unknown>>
```

Source: [`packages/api/gateway/src/index.ts`](../../packages/api/gateway/src/index.ts)
<!-- END GENERATED cordis-surface -->