Merge master (slash/input/session architecture) into web-session-model-selector

packages/host/apiproxy/src/api/commands.schema.ts

@@ -0,0 +1,45 @@
+/**
+ * commands domain zod schemas (names derived from map keys: commandListRequestSchema /
+ * commandListValueSchema / commandExecuteRequestSchema / commandExecuteValueSchema).
+ */
+
+import { z } from 'zod'
+import type { RequestPayload, ResponseValue } from './rpc-map.ts'
+import type { Wire } from './rpc.schema.ts'
+import { sessionIdSchema } from './sessions.schema.ts'
+import type { CommandDescriptor, CommandExecuteResult } from './commands.ts'
+
+/** CommandDescriptor row of command.list. */
+export const commandDescriptorSchema = z.object({
+  name: z.string().min(1),
+  description: z.string(),
+  input: z.object({ hint: z.string() }).optional(),
+}) satisfies z.ZodType<Wire<CommandDescriptor>>
+
+/** command.list request payload. */
+export const commandListRequestSchema = z.object({
+  sessionId: sessionIdSchema,
+}) satisfies z.ZodType<Wire<RequestPayload<'command.list'>>>
+
+/** command.list response value. */
+export const commandListValueSchema = z.object({
+  commands: z.array(commandDescriptorSchema),
+}) satisfies z.ZodType<Wire<ResponseValue<'command.list'>>>
+
+/** command.execute request payload. */
+export const commandExecuteRequestSchema = z.object({
+  sessionId: sessionIdSchema,
+  line: z.string(),
+}) satisfies z.ZodType<Wire<RequestPayload<'command.execute'>>>
+
+/** Detached command outcome (result slot of command.execute's value). */
+export const commandExecuteResultSchema = z.object({
+  kind: z.union([z.literal('success'), z.literal('error')]),
+  text: z.string().optional(),
+}) satisfies z.ZodType<Wire<CommandExecuteResult>>
+
+/** command.execute response value (matched=false carries no result). */
+export const commandExecuteValueSchema = z.object({
+  matched: z.boolean(),
+  result: commandExecuteResultSchema.optional(),
+}) satisfies z.ZodType<Wire<ResponseValue<'command.execute'>>>

packages/host/apiproxy/src/api/commands.ts

@@ -0,0 +1,48 @@
+/**
+ * commands domain contract: the web catalog/dispatch face of the host command
+ * registry (`ctx.commands`). Both methods address one session's agent via
+ * `sessionId` — every served session has an Agent (Session+Agent are born
+ * together), so there is no agent-less surface on this wire.
+ */
+
+import type { SessionId } from '@deepseek-ai/dsh-session/types'
+import type { RpcRequest, RpcResponse } from './rpc.ts'
+
+/**
+ * Handler-free command view served to clients. Wire mirror of the host
+ * registry descriptor (which stays host-side with its cordis dependencies);
+ * no source field — the host descriptor has none.
+ */
+export interface CommandDescriptor {
+  /** Lowercase command name without the leading slash. */
+  readonly name: string
+  /** Human-readable summary used in discovery UI. */
+  readonly description: string
+  /** Optional free-form input hint advertised to capable clients. */
+  readonly input?: { readonly hint: string }
+}
+
+/** Detached command outcome rendered directly by the requesting client. */
+export interface CommandExecuteResult {
+  readonly kind: 'success' | 'error'
+  readonly text?: string
+}
+
+/** Command-domain unary methods (the map keys command.* of RpcMethodMap). */
+export interface CommandsApi {
+  /**
+   * Lists the addressed agent's effective command catalog (name-sorted,
+   * globals plus its scoped shadows).
+   */
+  list(request: RpcRequest<{ sessionId: SessionId }>): Promise<RpcResponse<{ commands: readonly CommandDescriptor[] }>>
+
+  /**
+   * Parses and executes one slash-command line against the addressed agent
+   * without sending it to the model. matched=false when syntax or name does
+   * not resolve (the client falls back to its default sink). The signal rides
+   * beside the request, never on the wire: the fetch carrier's request signal
+   * cancels the running handler.
+   */
+  execute(request: RpcRequest<{ sessionId: SessionId; line: string }>, signal: AbortSignal):
+  Promise<RpcResponse<{ matched: boolean; result?: CommandExecuteResult }>>
+}

packages/host/apiproxy/src/api/events.schema.ts

@@ -10,7 +10,8 @@ import type { HostFrame, MuxFrame } from './events.ts'
 import type { Wire } from './rpc.schema.ts'
 import { rpcErrorSchema, rpcIdSchema } from './rpc.schema.ts'
 import { approvalRequestIdSchema } from './approvals.schema.ts'
-import { sessionEventSchema, sessionIdSchema, toolEventViewSchema } from './sessions.schema.ts'
+import { contentBlockSchema, sessionEventSchema, sessionIdSchema, toolEventViewSchema } from './sessions.schema.ts'
+import { workspaceViewSchema } from './workspace.schema.ts'
 
 /** Question shape validated strictly against core dsh-user-interaction. */
 export const askUserQuestionItemSchema = z.object({
@@ -34,14 +35,18 @@ export const muxFrameSchema = z.discriminatedUnion('type', [
   // and must fail loud here, not reach the composer.
   z.object({ type: z.literal('question/requested'), sessionId: sessionIdSchema, questions: z.array(askUserQuestionItemSchema).min(1) }),
   z.object({ type: z.literal('question/resolved'), sessionId: sessionIdSchema, questionRpcId: rpcIdSchema, outcome: z.union([z.literal('answered'), z.literal('cancelled')]) }),
+  // content/source reuse the wide passthroughs (both are merge-extensible in core).
+  z.object({ type: z.literal('session/queued'), sessionId: sessionIdSchema, content: z.array(contentBlockSchema), source: z.looseObject({ kind: z.string() }), steering: z.boolean() }),
   z.object({ type: z.literal('stream/error'), error: rpcErrorSchema }),
 ]) as unknown as z.ZodType<MuxFrame>
 
 /** HostFrame union (payload slot of a host-stream ServerRequest). */
 export const hostFrameSchema = z.discriminatedUnion('type', [
-  z.object({ type: z.literal('host/session-added'), sessionId: sessionIdSchema, parentSessionId: sessionIdSchema.optional() }),
+  z.object({ type: z.literal('host/session-added'), sessionId: sessionIdSchema, blank: z.boolean(), parentSessionId: sessionIdSchema.optional(), cwd: z.string().optional() }),
   z.object({ type: z.literal('host/session-removed'), sessionId: sessionIdSchema }),
   z.object({ type: z.literal('host/session-status'), sessionId: sessionIdSchema, running: z.boolean() }),
   z.object({ type: z.literal('host/agent-error'), sessionId: sessionIdSchema, message: z.string() }),
+  z.object({ type: z.literal('host/workspace-changed'), workspace: workspaceViewSchema }),
+  z.object({ type: z.literal('host/commands-changed') }),
   z.object({ type: z.literal('stream/error'), error: rpcErrorSchema }),
 ]) as unknown as z.ZodType<HostFrame>

packages/host/apiproxy/src/api/events.ts

@@ -8,10 +8,12 @@
 
 import type { AskUserQuestionItem } from '@deepseek-ai/dsh-user-interaction/types'
 import type { ApprovalOutcome, ApprovalRequestId } from '@deepseek-ai/dsh-user-approval/types'
+import type { ContentBlock, MessageSource } from '@deepseek-ai/dsh-llm/types'
 import type { CallId } from '@deepseek-ai/dsh-llm/brand'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
 import type { ToolCallView, ToolResultView } from '@deepseek-ai/dsh-tools/presentation'
 import type { RpcError, RpcId, RpcRequest } from './rpc.ts'
+import type { WorkspaceView } from './workspace.ts'
 
 // Client-side consumers take the render-intent vocabulary from the contract;
 // dsh-tools remains its owner.
@@ -60,12 +62,41 @@ export type MuxFrame =
   | { type: 'approval/resolved'; sessionId: SessionId; approvalId: ApprovalRequestId; outcome: ApprovalOutcome }
   | { type: 'question/requested'; sessionId: SessionId; questions: AskUserQuestionItem[] }
   | { type: 'question/resolved'; sessionId: SessionId; questionRpcId: RpcId; outcome: 'answered' | 'cancelled' }
+  /**
+   * A message entered the addressed agent's inbox (`agent/queued` passthrough:
+   * a queued message is not model-visible, so there is no session event to
+   * ride — this transient frame is the only wire signal). On stream open the
+   * host replays the current queue snapshot for every attached session (same
+   * refresh-recovery baseline as pending questions); queue clearing on cancel
+   * has no dedicated frame — clients fold it from the status flip.
+   * source carries the prompt's rpcId when the message came over this wire
+   * (the client's provisional-echo reconciliation key).
+   */
+  | { type: 'session/queued'; sessionId: SessionId; content: ContentBlock[]; source: MessageSource; steering: boolean }
   | { type: 'stream/error'; error: RpcError }
 
-/** Host stream frames. session-added carries the lineage anchor; agent-error is the only outlet for live failures with no turn position. */
+/**
+ * Host stream frames. session-added carries the lineage anchor, the project
+ * cwd, and the blank bit (the list-summary fields a client cannot wait for a
+ * refresh to learn); the frame fires at session/created, so blank is
+ * constantly true — clients flip it on the session's first
+ * `host/session-status(running:true)` (a blank session never runs), and a
+ * reconnecting client takes `session.list`'s summary.blank as authoritative.
+ * agent-error is the only outlet for live failures with no turn position;
+ * workspace-changed pushes the full new snapshot after every durable
+ * workspace mutation (create/attach/order change — the client upserts, while
+ * `workspace.list` provides the reconnect baseline).
+ */
 export type HostFrame =
-  | { type: 'host/session-added'; sessionId: SessionId; parentSessionId?: SessionId }
+  | { type: 'host/session-added'; sessionId: SessionId; blank: boolean; parentSessionId?: SessionId; cwd?: string }
   | { type: 'host/session-removed'; sessionId: SessionId }
   | { type: 'host/session-status'; sessionId: SessionId; running: boolean }
   | { type: 'host/agent-error'; sessionId: SessionId; message: string }
+  | { type: 'host/workspace-changed'; workspace: WorkspaceView }
+  /**
+   * The command registry changed (`commands/change` passthrough). Pure
+   * invalidation signal, no payload: clients refetch `command.list` in the
+   * background rather than diffing.
+   */
+  | { type: 'host/commands-changed' }
   | { type: 'stream/error'; error: RpcError }

packages/host/apiproxy/src/api/index.ts

@@ -6,6 +6,9 @@
 
 import type { SessionsApi } from './sessions.ts'
 import type { HostApi } from './host.ts'
+import type { WorkspaceApi } from './workspace.ts'
+import type { CommandsApi } from './commands.ts'
+import type { SkillsApi } from './skills.ts'
 import type { EventsApi } from './events.ts'
 import type { ClientResponse, RpcReceipt } from './rpc.ts'
 
@@ -13,6 +16,9 @@ import type { ClientResponse, RpcReceipt } from './rpc.ts'
 export interface ApiProxy {
   sessions: SessionsApi
   host: HostApi
+  workspace: WorkspaceApi
+  commands: CommandsApi
+  skills: SkillsApi
   events: EventsApi
   /** Response entry for server-requests (client-response, echoing their rpcId); not a domain method (four-quadrant model). */
   respond(message: ClientResponse): Promise<RpcReceipt>
@@ -24,6 +30,9 @@ export type {
   SessionModels, SessionsApi, SessionSummary,
 } from './sessions.ts'
 export type { HostApi } from './host.ts'
+export type { WorkspaceApi, WorkspaceId, WorkspaceView } from './workspace.ts'
+export type { CommandsApi, CommandDescriptor, CommandExecuteResult } from './commands.ts'
+export type { SkillsApi, SkillEntry } from './skills.ts'
 export type { EventsApi, MuxFrame, HostFrame, ToolCallView, ToolEventView, ToolResultView } from './events.ts'
 export type { ApprovalResponsePayload } from './approvals.ts'
 export type { QuestionResponsePayload } from './questions.ts'

packages/host/apiproxy/src/api/rpc-map.ts

@@ -6,9 +6,16 @@
 
 import type { SessionsApi } from './sessions.ts'
 import type { HostApi } from './host.ts'
+import type { WorkspaceApi } from './workspace.ts'
+import type { CommandsApi } from './commands.ts'
+import type { SkillsApi } from './skills.ts'
 import type { RpcResponse } from './rpc.ts'
 
-/** Method name → method signature. Signatures are the single source of truth; payload/value types are always derived from here. */
+/**
+ * Method name → method signature. Signatures are the single source of truth; payload/value
+ * types are always derived from here. A method may declare a trailing AbortSignal after the
+ * request (command.execute): the carrier passes its request signal, never a wire field.
+ */
 export interface RpcMethodMap {
   'session.list': SessionsApi['list']
   'session.create': SessionsApi['create']
@@ -18,6 +25,13 @@ export interface RpcMethodMap {
   'session.prompt': SessionsApi['prompt']
   'session.cancel': SessionsApi['cancel']
   'host.describe': HostApi['describe']
+  'workspace.list': WorkspaceApi['list']
+  'workspace.create': WorkspaceApi['create']
+  'workspace.rename': WorkspaceApi['rename']
+  'workspace.insertSessionBefore': WorkspaceApi['insertSessionBefore']
+  'command.list': CommandsApi['list']
+  'command.execute': CommandsApi['execute']
+  'skill.list': SkillsApi['list']
 }
 
 /** Business request payload of method K (reaches through the RpcRequest narrow form to payload). */

packages/host/apiproxy/src/api/rpc.schema.ts

@@ -35,7 +35,12 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
   z.object({ code: z.literal('bad-request'), message: z.string(), details: z.object({ issues: z.array(z.custom<ZodIssue>()) }) }),
   z.object({ code: z.literal('cancelled'), message: z.string(), details: z.object({}) }),
   z.object({ code: z.literal('session-not-found'), message: z.string(), details: z.object({ sessionId: z.string() }) }),
-  z.object({ code: z.literal('model-unavailable'), message: z.string(), details: z.object({ provider: z.string(), model: z.string() }) }),
+  z.object({ code: z.literal('session-conflict'), message: z.string(), details: z.object({ sessionId: z.string(), requestedCwd: z.string(), existingCwd: z.string().optional() }) }),
+  z.object({ code: z.literal('workspace-attach-failed'), message: z.string(), details: z.object({ sessionId: z.string(), workspaceId: z.string() }) }),
+  z.object({ code: z.literal('workspace-not-found'), message: z.string(), details: z.object({ workspaceId: z.string() }) }),
+  z.object({ code: z.literal('workspace-invalid-path'), message: z.string(), details: z.object({ path: z.string() }) }),
+  z.object({ code: z.literal('workspace-name-conflict'), message: z.string(), details: z.object({ name: z.string() }) }),
+  z.object({ code: z.literal('workspace-move-invalid'), message: z.string(), details: z.object({ workspaceId: z.string(), sessionId: z.string(), beforeSessionId: z.string().optional() }) }),
   z.object({ code: z.literal('agent-busy'), message: z.string(), details: z.object({ reason: z.string() }) }),
   z.object({ code: z.literal('internal'), message: z.string(), details: z.object({}) }),
 ]) as unknown as z.ZodType<RpcError>

packages/host/apiproxy/src/api/rpc.ts

@@ -32,7 +32,12 @@ export interface RpcErrorDetailsMap {
   'bad-request': { issues: ZodIssue[] }
   'cancelled': {}
   'session-not-found': { sessionId: SessionId }
-  'model-unavailable': { provider: string; model: string }
+  'session-conflict': { sessionId: SessionId; requestedCwd: string; existingCwd?: string }
+  'workspace-attach-failed': { sessionId: SessionId; workspaceId: string }
+  'workspace-not-found': { workspaceId: string }
+  'workspace-invalid-path': { path: string }
+  'workspace-name-conflict': { name: string }
+  'workspace-move-invalid': { workspaceId: string; sessionId: SessionId; beforeSessionId?: SessionId }
   'agent-busy': { reason: string }
   'internal': {}
 }

packages/host/apiproxy/src/api/sessions.schema.ts

@@ -14,10 +14,19 @@ import type {
   SessionSummary,
 } from './sessions.ts'
 import type { ToolEventView } from './events.ts'
+import type { WorkspaceId } from './workspace.ts'
 
 /** SessionId: one brand cast after shape validation (the only cast point in this domain). */
 export const sessionIdSchema = z.string().min(1) as unknown as z.ZodType<SessionId>
 
+/**
+ * WorkspaceId: the workspace domain's one brand cast. Hosted here rather
+ * than in workspace.schema because session.create references it while
+ * workspace.schema references sessionIdSchema — schema modules must stay a
+ * DAG (both casts used at module top level; a cycle is a load-time TDZ).
+ */
+export const workspaceIdSchema = z.string().min(1) as unknown as z.ZodType<WorkspaceId>
+
 /** SessionEvent passthrough: strict envelope, wide data (the client fold handles unknown types via its documented default). */
 export const sessionEventSchema = z.object({
   type: z.string(),
@@ -33,6 +42,7 @@ export const sessionSummarySchema = z.object({
   sessionId: sessionIdSchema,
   updatedAt: z.number(),
   running: z.boolean(),
+  blank: z.boolean(),
   parentSessionId: sessionIdSchema.optional(),
   cwd: z.string().optional(),
 }) satisfies z.ZodType<Wire<SessionSummary>>
@@ -47,10 +57,15 @@ export const sessionListValueSchema = z.object({
   items: z.array(sessionSummarySchema),
 }) satisfies z.ZodType<Wire<ResponseValue<'session.list'>>>
 
-/** session.create request payload. */
+/** session.create request payload (at most one of workspaceId / cwd). */
 export const sessionCreateRequestSchema = z.object({
+  workspaceId: workspaceIdSchema.optional(),
   cwd: z.string().optional(),
-}) satisfies z.ZodType<Wire<RequestPayload<'session.create'>>>
+  sessionId: sessionIdSchema.optional(),
+}).refine(
+  payload => payload.workspaceId === undefined || payload.cwd === undefined,
+  { message: 'session.create accepts workspaceId or cwd, not both' },
+) satisfies z.ZodType<Wire<RequestPayload<'session.create'>>>
 
 /** session.create response value. */
 export const sessionCreateValueSchema = z.object({

packages/host/apiproxy/src/api/sessions.ts

@@ -8,6 +8,7 @@ import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type { SessionEvent, SessionId } from '@deepseek-ai/dsh-session/types'
 import type { RpcId, RpcRequest, RpcResponse } from './rpc.ts'
 import type { ToolEventView } from './events.ts'
+import type { WorkspaceId } from './workspace.ts'
 
 declare module '@deepseek-ai/dsh-llm' {
   interface MessageSourceMap {
@@ -88,6 +89,14 @@ export interface SessionSummary {
   updatedAt: number
   /** Status of the attached agent; always false for cold (unattached) sessions. */
   running: boolean
+  /**
+   * Derived emptiness bit: true while the session log holds zero events (no
+   * user message yet). Clients hide blank sessions from lists and reuse them
+   * for New Session on the same workspace. Always false for cold sessions —
+   * lazy persistence keeps a never-appended session out of the store, so a
+   * listed cold session necessarily has events.
+   */
+  blank: boolean
   /** fork/spawn lineage (session.header.parentSession passthrough); absent for root sessions. */
   parentSessionId?: SessionId
   /** Session working directory (header.cwd passthrough); absent when unrecorded. */
@@ -99,8 +108,16 @@ export interface SessionsApi {
   /** Lists persisted sessions (updatedAt descending). v1 returns everything; cursor is a reserved seat, unimplemented. */
   list(request: RpcRequest<{ cursor?: string }>): Promise<RpcResponse<{ items: SessionSummary[] }>>
 
-  /** Creates a new session (and its agent, idle and standing by). */
-  create(request: RpcRequest<{ cwd?: string }>): Promise<RpcResponse<{ sessionId: SessionId }>>
+  /**
+   * Creates a real session and its idle agent. At most one of `workspaceId` /
+   * `cwd` is accepted; an omitted project uses the Host cwd. A caller may
+   * preallocate `sessionId`: retries with the same id and cwd return the same
+   * session, while a different cwd fails with `session-conflict`. Workspace
+   * creation attaches the session after publication; an attach failure
+   * returns `workspace-attach-failed` with the published session id.
+   */
+  create(request: RpcRequest<{ workspaceId?: WorkspaceId; cwd?: string; sessionId?: SessionId }>):
+  Promise<RpcResponse<{ sessionId: SessionId }>>
 
   /**
    * Reads a window of history events; page boundaries align to message boundaries: one page =

packages/host/apiproxy/src/api/skills.schema.ts

@@ -0,0 +1,27 @@
+/**
+ * skills domain zod schemas (names derived from map keys: skillListRequestSchema /
+ * skillListValueSchema).
+ */
+
+import { z } from 'zod'
+import type { RequestPayload, ResponseValue } from './rpc-map.ts'
+import type { Wire } from './rpc.schema.ts'
+import { sessionIdSchema } from './sessions.schema.ts'
+import type { SkillEntry } from './skills.ts'
+
+/** SkillEntry row of skill.list. */
+export const skillEntrySchema = z.object({
+  name: z.string().min(1),
+  description: z.string(),
+  whenToUse: z.string().optional(),
+}) satisfies z.ZodType<Wire<SkillEntry>>
+
+/** skill.list request payload. */
+export const skillListRequestSchema = z.object({
+  sessionId: sessionIdSchema,
+}) satisfies z.ZodType<Wire<RequestPayload<'skill.list'>>>
+
+/** skill.list response value. */
+export const skillListValueSchema = z.object({
+  skills: z.array(skillEntrySchema),
+}) satisfies z.ZodType<Wire<ResponseValue<'skill.list'>>>

packages/host/apiproxy/src/api/skills.ts

@@ -0,0 +1,25 @@
+/**
+ * skills domain contract: read-only skill catalog lookup addressed by session.
+ * The session's header cwd resolves to the canonical project root host-side —
+ * the client never submits a raw path, and skill lookup never creates or
+ * resumes an Agent.
+ */
+
+import type { SessionId } from '@deepseek-ai/dsh-session/types'
+import type { RpcRequest, RpcResponse } from './rpc.ts'
+
+/** Skill catalog row (wire projection of the host SkillSummary; provider/source vocabulary stays host-side). */
+export interface SkillEntry {
+  /** Kebab-case identifier referenced as `<skill>name</skill>` in prompts. */
+  readonly name: string
+  /** Short routing description. */
+  readonly description: string
+  /** Optional extra routing guidance. */
+  readonly whenToUse?: string
+}
+
+/** Skill-domain unary methods (the map key skill.* of RpcMethodMap). */
+export interface SkillsApi {
+  /** Lists model-invocable skills for the addressed session's project root. */
+  list(request: RpcRequest<{ sessionId: SessionId }>): Promise<RpcResponse<{ skills: readonly SkillEntry[] }>>
+}

packages/host/apiproxy/src/api/workspace.schema.ts

@@ -0,0 +1,72 @@
+/**
+ * workspace domain zod schemas (names derived from map keys). The
+ * WorkspaceId brand cast lives in sessions.schema (see the note there) and
+ * is re-exported here as the domain-local name.
+ */
+
+import { z } from 'zod'
+import type { RequestPayload, ResponseValue } from './rpc-map.ts'
+import type { Wire } from './rpc.schema.ts'
+import type { WorkspaceView } from './workspace.ts'
+import { sessionIdSchema, workspaceIdSchema } from './sessions.schema.ts'
+
+export { workspaceIdSchema } from './sessions.schema.ts'
+
+/** WorkspaceView row of every workspace.* response. */
+export const workspaceViewSchema = z.object({
+  workspaceId: workspaceIdSchema,
+  path: z.string(),
+  title: z.string(),
+  sessionIds: z.array(sessionIdSchema),
+  createdAt: z.string(),
+  updatedAt: z.string(),
+}) satisfies z.ZodType<Wire<WorkspaceView>>
+
+/** workspace.list request payload (empty object literal). */
+export const workspaceListRequestSchema = z.object({}) satisfies z.ZodType<Wire<RequestPayload<'workspace.list'>>>
+
+/** workspace.list response value. */
+export const workspaceListValueSchema = z.object({
+  items: z.array(workspaceViewSchema),
+}) satisfies z.ZodType<Wire<ResponseValue<'workspace.list'>>>
+
+/** workspace.create request payload: exactly one of path/name (the contract's create spellings). */
+export const workspaceCreateRequestSchema = z.object({
+  path: z.string().optional(),
+  name: z.string().optional(),
+}).refine(
+  payload => (payload.path === undefined) !== (payload.name === undefined),
+  { message: 'workspace.create requires exactly one of path / name' },
+) satisfies z.ZodType<Wire<RequestPayload<'workspace.create'>>>
+
+/** workspace.create response value. */
+export const workspaceCreateValueSchema = z.object({
+  workspace: workspaceViewSchema,
+  created: z.boolean(),
+}) satisfies z.ZodType<Wire<ResponseValue<'workspace.create'>>>
+
+/** workspace.rename request payload: the new title must be non-blank. */
+export const workspaceRenameRequestSchema = z.object({
+  workspaceId: workspaceIdSchema,
+  title: z.string(),
+}).refine(
+  payload => payload.title.trim() !== '',
+  { message: 'workspace.rename requires a non-blank title' },
+) satisfies z.ZodType<Wire<RequestPayload<'workspace.rename'>>>
+
+/** workspace.rename response value. */
+export const workspaceRenameValueSchema = z.object({
+  workspace: workspaceViewSchema,
+}) satisfies z.ZodType<Wire<ResponseValue<'workspace.rename'>>>
+
+/** workspace.insertSessionBefore request payload (anchor omitted = append to end). */
+export const workspaceInsertSessionBeforeRequestSchema = z.object({
+  workspaceId: workspaceIdSchema,
+  sessionId: sessionIdSchema,
+  beforeSessionId: sessionIdSchema.optional(),
+}) satisfies z.ZodType<Wire<RequestPayload<'workspace.insertSessionBefore'>>>
+
+/** workspace.insertSessionBefore response value. */
+export const workspaceInsertSessionBeforeValueSchema = z.object({
+  workspace: workspaceViewSchema,
+}) satisfies z.ZodType<Wire<ResponseValue<'workspace.insertSessionBefore'>>>

packages/host/apiproxy/src/api/workspace.ts

@@ -0,0 +1,81 @@
+/**
+ * workspace domain contract. Wire projection of the host-side workspace
+ * entity (@deepseek-ai/dsh-workspace): a stable id over a directory path,
+ * a display title, and the ordered session account. Method signatures are the
+ * source of truth, same as the sessions domain.
+ */
+
+import type { SessionId } from '@deepseek-ai/dsh-session/types'
+import type { Branded } from '@deepseek-ai/dsh-brand'
+import type { RpcRequest, RpcResponse } from './rpc.ts'
+
+/**
+ * Wire-side workspace id brand. Deliberately re-declared here rather than
+ * imported from dsh-workspace: api/ must stay browser-importable with zero
+ * host-package dependencies, and the brand string matches, so both sides
+ * agree structurally.
+ */
+export type WorkspaceId = Branded<'WorkspaceId'>
+
+/** One workspace row: the record projection every workspace.* value carries. */
+export interface WorkspaceView {
+  workspaceId: WorkspaceId
+  /** Canonical directory path (host-side realpath canon). */
+  path: string
+  /** Unique display title (defaults to the path basename at create). */
+  title: string
+  /**
+   * Sessions accounted under this workspace, in manually owned order
+   * (attach prepends, insertSessionBefore reorders; activity never does).
+   */
+  sessionIds: SessionId[]
+  /** ISO-8601 creation instant. */
+  createdAt: string
+  /** ISO-8601 last-mutation instant. */
+  updatedAt: string
+}
+
+/** Workspace-domain unary methods (the map keys workspace.* of RpcMethodMap). */
+export interface WorkspaceApi {
+  /** Lists all workspaces in the registry's durable display order. */
+  list(request: RpcRequest<{}>): Promise<RpcResponse<{ items: WorkspaceView[] }>>
+
+  /**
+   * Creates (or idempotently resolves) a workspace. Exactly one of `path` /
+   * `name` (schema-enforced): `path` registers an EXISTING directory (no
+   * mkdir — a missing or non-directory path fails with `workspace-invalid-path`);
+   * `name` is a single path segment the host mkdirs under its default project
+   * root before registering. Either spelling resolving to a directory already
+   * owned by a workspace returns that workspace (`created: false`) for the
+   * existing-folder spelling. Create-by-name rejects an existing title with
+   * `workspace-name-conflict`; a new path whose basename duplicates another
+   * Workspace title is rejected by the registry with the same code.
+   * A new name-created workspace uses `name` as both directory name and title;
+   * a path-created workspace uses the registry's basename title default.
+   */
+  create(request: RpcRequest<{ path?: string; name?: string }>):
+  Promise<RpcResponse<{ workspace: WorkspaceView; created: boolean }>>
+
+  /**
+   * Renames a workspace. `title` is trimmed and must be non-empty
+   * (schema-enforced). An unknown id fails with `workspace-not-found`; a
+   * title equal to another workspace's fails with `workspace-name-conflict`.
+   * Renaming to the current title is a no-op success (no durable write).
+   */
+  rename(request: RpcRequest<{ workspaceId: WorkspaceId; title: string }>):
+  Promise<RpcResponse<{ workspace: WorkspaceView }>>
+
+  /**
+   * Moves an accounted session within its workspace's manual order,
+   * DOM-insertBefore-like: with `beforeSessionId` the session is inserted
+   * before that anchor; omitted appends to the end. An unknown workspace
+   * fails with `workspace-not-found`; a session or anchor not accounted by
+   * the workspace fails with `workspace-move-invalid`. A move to the current
+   * position is a no-op success.
+   */
+  insertSessionBefore(request: RpcRequest<{
+    workspaceId: WorkspaceId
+    sessionId: SessionId
+    beforeSessionId?: SessionId
+  }>): Promise<RpcResponse<{ workspace: WorkspaceView }>>
+}

packages/host/apiproxy/src/fetch/client.ts

@@ -23,6 +23,14 @@ import {
   sessionPromptValueSchema,
   sessionSelectModelValueSchema,
 } from '../api/sessions.schema.ts'
+import {
+  workspaceCreateValueSchema,
+  workspaceInsertSessionBeforeValueSchema,
+  workspaceListValueSchema,
+  workspaceRenameValueSchema,
+} from '../api/workspace.schema.ts'
+import { commandExecuteValueSchema, commandListValueSchema } from '../api/commands.schema.ts'
+import { skillListValueSchema } from '../api/skills.schema.ts'
 
 /**
  * Client consumption face of the contract (shape a): same domain tree as ApiProxy, but unary
@@ -52,6 +60,19 @@ export interface IApiClient {
   host: {
     describe(payload: RequestPayload<'host.describe'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'host.describe'>>>
   }
+  workspace: {
+    list(payload: RequestPayload<'workspace.list'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.list'>>>
+    create(payload: RequestPayload<'workspace.create'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.create'>>>
+    rename(payload: RequestPayload<'workspace.rename'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.rename'>>>
+    insertSessionBefore(payload: RequestPayload<'workspace.insertSessionBefore'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'workspace.insertSessionBefore'>>>
+  }
+  commands: {
+    list(payload: RequestPayload<'command.list'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'command.list'>>>
+    execute(payload: RequestPayload<'command.execute'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'command.execute'>>>
+  }
+  skills: {
+    list(payload: RequestPayload<'skill.list'>, signal?: AbortSignal): Promise<RpcResponse<ResponseValue<'skill.list'>>>
+  }
   events: {
     mux(payload: Parameters<ApiProxy['events']['mux']>[0]['payload'], signal: AbortSignal, onOpen?: () => void): AsyncIterable<RpcRequest<MuxFrame>>
     host(payload: Parameters<ApiProxy['events']['host']>[0]['payload'], signal: AbortSignal, onOpen?: () => void): AsyncIterable<RpcRequest<HostFrame>>
@@ -73,6 +94,13 @@ const UNARY_VALUE_SCHEMAS: { [K in keyof RpcMethodMap]: z.ZodType<Wire<ResponseV
   'session.prompt': sessionPromptValueSchema,
   'session.cancel': sessionCancelValueSchema,
   'host.describe': hostDescribeValueSchema,
+  'workspace.list': workspaceListValueSchema,
+  'workspace.create': workspaceCreateValueSchema,
+  'workspace.rename': workspaceRenameValueSchema,
+  'workspace.insertSessionBefore': workspaceInsertSessionBeforeValueSchema,
+  'command.list': commandListValueSchema,
+  'command.execute': commandExecuteValueSchema,
+  'skill.list': skillListValueSchema,
 }
 
 /** Default unary timeout (rpc-compare 2026-07-19: a hung host must not leave callers pending forever). */
@@ -261,6 +289,22 @@ export abstract class AbstractApiClient implements IApiClient {
     describe: (payload, signal) => this.callUnary('host.describe', payload, signal),
   }
 
+  readonly workspace: IApiClient['workspace'] = {
+    list: (payload, signal) => this.callUnary('workspace.list', payload, signal),
+    create: (payload, signal) => this.callUnary('workspace.create', payload, signal),
+    rename: (payload, signal) => this.callUnary('workspace.rename', payload, signal),
+    insertSessionBefore: (payload, signal) => this.callUnary('workspace.insertSessionBefore', payload, signal),
+  }
+
+  readonly commands: IApiClient['commands'] = {
+    list: (payload, signal) => this.callUnary('command.list', payload, signal),
+    execute: (payload, signal) => this.callUnary('command.execute', payload, signal),
+  }
+
+  readonly skills: IApiClient['skills'] = {
+    list: (payload, signal) => this.callUnary('skill.list', payload, signal),
+  }
+
   readonly events: IApiClient['events'] = {
     mux: (payload, signal, onOpen) => this.openMux(payload, signal, onOpen),
     host: (payload, signal, onOpen) => this.openHost(payload, signal, onOpen),

packages/host/apiproxy/src/fetch/handler.ts

@@ -24,6 +24,14 @@ import {
   sessionSelectModelRequestSchema,
 } from '../api/sessions.schema.ts'
 import { hostDescribeRequestSchema } from '../api/host.schema.ts'
+import {
+  workspaceCreateRequestSchema,
+  workspaceInsertSessionBeforeRequestSchema,
+  workspaceListRequestSchema,
+  workspaceRenameRequestSchema,
+} from '../api/workspace.schema.ts'
+import { commandExecuteRequestSchema, commandListRequestSchema } from '../api/commands.schema.ts'
+import { skillListRequestSchema } from '../api/skills.schema.ts'
 
 /**
  * Unary dispatch table, keyed by (and compiler-locked to) RpcMethodMap: a map row without a
@@ -31,11 +39,13 @@ import { hostDescribeRequestSchema } from '../api/host.schema.ts'
  * payload type — a schema pasted onto the wrong row is a type error, not a runtime surprise.
  * Schemas anchor to the Wire<> widening (the repo-wide exactOptionalPropertyTypes accommodation
  * documented on Wire); the dispatch point carries the one Wire→exact cast.
+ * Every invoke receives the carrier Request's signal; methods whose contract
+ * declares a signal parameter (command.execute) forward it, the rest ignore it.
  */
 type UnaryRoutes = {
   [K in keyof RpcMethodMap]: {
     schema: z.ZodType<Wire<RequestPayload<K>>>
-    invoke(api: ApiProxy, request: RpcRequest<RequestPayload<K>>): Promise<RpcResponse<ResponseValue<K>>>
+    invoke(api: ApiProxy, request: RpcRequest<RequestPayload<K>>, signal: AbortSignal): Promise<RpcResponse<ResponseValue<K>>>
   }
 }
 
@@ -48,6 +58,13 @@ const UNARY_ROUTES: UnaryRoutes = {
   'session.prompt': { schema: sessionPromptRequestSchema, invoke: (api, r) => api.sessions.prompt(r) },
   'session.cancel': { schema: sessionCancelRequestSchema, invoke: (api, r) => api.sessions.cancel(r) },
   'host.describe': { schema: hostDescribeRequestSchema, invoke: (api, r) => api.host.describe(r) },
+  'workspace.list': { schema: workspaceListRequestSchema, invoke: (api, r) => api.workspace.list(r) },
+  'workspace.create': { schema: workspaceCreateRequestSchema, invoke: (api, r) => api.workspace.create(r) },
+  'workspace.rename': { schema: workspaceRenameRequestSchema, invoke: (api, r) => api.workspace.rename(r) },
+  'workspace.insertSessionBefore': { schema: workspaceInsertSessionBeforeRequestSchema, invoke: (api, r) => api.workspace.insertSessionBefore(r) },
+  'command.list': { schema: commandListRequestSchema, invoke: (api, r) => api.commands.list(r) },
+  'command.execute': { schema: commandExecuteRequestSchema, invoke: (api, r, signal) => api.commands.execute(r, signal) },
+  'skill.list': { schema: skillListRequestSchema, invoke: (api, r) => api.skills.list(r) },
 }
 
 /** Route lookup that narrows an arbitrary path segment to a map key (single cast point for the string→key refinement). */
@@ -83,14 +100,16 @@ function fullResponse(narrow: RpcResponse<unknown>): Response {
 // K appears once in the signature but ties the UNARY_ROUTES[K] row lookup to its own
 // schema/invoke pairing; a union parameter degrades the row to an uninvokable intersection.
 // eslint-disable-next-line @typescript-eslint/no-unnecessary-type-parameters
-async function handleUnary<K extends keyof RpcMethodMap>(api: ApiProxy, method: K, message: ClientRequest): Promise<Response> {
+async function handleUnary<K extends keyof RpcMethodMap>(
+  api: ApiProxy, method: K, message: ClientRequest, signal: AbortSignal,
+): Promise<Response> {
   const route = UNARY_ROUTES[method]
   const payload = route.schema.safeParse(message.payload)
   if (!payload.success) {
     return errorResponse(message.rpcId, { code: 'bad-request', message: `invalid payload for ${method}`, details: { issues: payload.error.issues } })
   }
   try {
-    return fullResponse(await route.invoke(api, { rpcId: message.rpcId, payload: payload.data }))
+    return fullResponse(await route.invoke(api, { rpcId: message.rpcId, payload: payload.data }, signal))
   } catch (error: unknown) {
     // The impl never throws business errors; reaching here means the implementation itself crashed — 500, carrier layer.
     return new Response(`handler failure: ${String(error)}`, { status: 500 })
@@ -195,7 +214,7 @@ export function toFetchHandler(api: ApiProxy): { fetch: typeof fetch } {
       if (message.method !== method) {
         return errorResponse(message.rpcId, { code: 'bad-request', message: `method "${message.method}" does not match path "${method}"`, details: { issues: [] } })
       }
-      return handleUnary(api, method, message)
+      return handleUnary(api, method, message, req.signal)
     },
   }
 }

packages/host/apiproxy/src/index.ts

@@ -1,13 +1,85 @@
 /**
- * @deepseek-ai/dsh-host-apiproxy — the front layer every client shape shares:
- * the ApiProxy contract (api/: types + zod schemas, browser-safe) and the
- * fetch carrier pair (fetch/: toFetchHandler on the host side, AbstractApiClient +
- * platform subclasses on the client side). Host assembly (bootHost/createApiProxy/startHost)
- * lives in @deepseek-ai/dsh-host-runtime.
+ * @deepseek-ai/dsh-host-apiproxy — the API gateway every client shape shares:
+ * the ApiProxy contract (api/: types + zod schemas, browser-safe), the fetch
+ * carrier pair (fetch/: toFetchHandler on the host side, AbstractApiClient +
+ * platform subclasses on the client side), and the host-side implementation
+ * (api-proxy.ts: createApiProxy + the ApiProxyService gateway plugin providing
+ * `ctx.apiProxy`). Transport-agnostic by design: this package registers no
+ * routes — carriers (HTTP today, IPC later) wrap `ctx.apiProxy` themselves.
  */
 
+import { resolve } from 'node:path'
+import { Context, Service } from 'cordis'
+import z from 'schemastery'
+import type { ApiProxy } from './api/index.ts'
+import { createApiProxy } from './api-proxy.ts'
+
 export type * from './api/index.ts'
 export { RpcId } from './api/rpc.ts'
 export { toFetchHandler } from './fetch/handler.ts'
 export { AbstractApiClient, InProcessApiClient } from './fetch/client.ts'
 export type { IApiClient } from './fetch/client.ts'
+export { createApiProxy } from './api-proxy.ts'
+export type { ApiProxyDefaults } from './api-proxy.ts'
+
+declare module 'cordis' {
+  interface Context {
+    /** The host-side ApiProxy implementation (the transport-agnostic gateway face). */
+    apiProxy: ApiProxy
+  }
+}
+
+/** Gateway plugin config: host-level agent routing and Workspace creation root. */
+export interface Config {
+  /** Default provider route for created/resumed agents. */
+  provider: string
+  /** Default model id. */
+  model: string
+  /** Parent directory for name-created Workspaces; defaults to the Host cwd. */
+  workspaceRoot?: string
+}
+
+/**
+ * The API gateway service: implements the ApiProxy contract over the composed
+ * host context and provides it as `ctx.apiProxy`. The Host cwd is the default
+ * project directory and the fallback parent for name-created Workspaces.
+ */
+export class ApiProxyService extends Service implements ApiProxy {
+  static inject = ['agents', 'sessions', 'tools', 'userInteraction', 'workspace']
+
+  static Config: z<Config> = z.object({
+    provider: z.string().required(),
+    model: z.string().required(),
+    workspaceRoot: z.string(),
+  })
+
+  readonly sessions: ApiProxy['sessions']
+  readonly workspace: ApiProxy['workspace']
+  readonly host: ApiProxy['host']
+  readonly commands: ApiProxy['commands']
+  readonly skills: ApiProxy['skills']
+  readonly events: ApiProxy['events']
+  readonly respond: ApiProxy['respond']
+
+  constructor(ctx: Context, config: Config) {
+    super(ctx, 'apiProxy')
+    const cwd = process.cwd()
+    const api = createApiProxy(ctx, {
+      provider: config.provider,
+      model: config.model,
+      cwd,
+      workspaceRoot: resolve(config.workspaceRoot ?? cwd),
+    })
+    this.sessions = api.sessions
+    this.workspace = api.workspace
+    this.host = api.host
+    this.commands = api.commands
+    this.skills = api.skills
+    this.events = api.events
+    // createApiProxy returns closures (no `this` capture); bind only satisfies
+    // the unbound-method lint without changing behavior.
+    this.respond = api.respond.bind(api)
+  }
+}
+
+export default ApiProxyService

packages/host/apiproxy/src/invariant.ts

@@ -15,11 +15,12 @@ export const name = 'host-apiproxy-invariant'
 export const inject = ['invariants']
 
 /**
- * No runtime invariant: this package is the wire contract layer (types,
- * schemas, fetch carrier glue) — it emits no cordis events and owns no
- * mutable cross-plugin relation. rpcId round-trip and schema acceptance are
- * enforced at the carrier boundary and exercised by the protocol-isomorphism
- * suite; the live implementation relations belong to dsh-host-runtime.
+ * No runtime invariant: this package is the wire contract layer plus the
+ * host-side gateway over services owned elsewhere — it emits no cordis events
+ * of its own; the session/agent event streams it projects are asserted by
+ * their owning packages' companions. rpcId round-trip and schema acceptance
+ * are enforced at the carrier boundary and exercised by the
+ * protocol-isomorphism suite.
  */
 const install: InvariantInstaller = () => {}