fix(apiproxy): configure session export compression

Session-log ZIP entries always used DEFLATE level 6 even though compression level is a deployment tradeoff: CPU-constrained hosts may prefer low latency while bandwidth-constrained hosts may prefer smaller archives. A hardcoded level also violated the repository rule that deployment-varying plugin choices live in validated Config.

Add sessionExportCompressionLevel to ApiProxyService.Config as an integer 0-9 with default 6, resolve the same default once for direct createApiProxy callers, and pass the required level into the streaming module. Tests prove schema defaulting and rejection as well as a level-0 versus level-9 archive-size difference with identical extracted content. The generated config catalog, bilingual gateway README, and feature note document the knob and its tradeoff.

packages/host/apiproxy/src/api-proxy.ts

@@ -43,11 +43,13 @@ import type {
   WorkspaceId, WorkspaceView,
 } from './api/index.ts'
 import {
+  DEFAULT_SESSION_LOG_COMPRESSION_LEVEL,
   flushLiveSessionLog,
   sessionLogExportDeps,
   sessionLogZipFilename,
   streamSessionLogZip,
   type SessionLogExportReady,
+  type SessionLogCompressionLevel,
 } from './session-export.ts'
 import type { SessionRawArtifact } from '@deepseek-ai/dsh-session-persistence'
 import {
@@ -544,6 +546,8 @@ export interface ApiProxyDefaults {
   openPath?: (path: string, signal: AbortSignal) => Promise<void>
   /** Native text-editor handoff; injectable for settings-document tests. */
   openTextFile?: (path: string, signal: AbortSignal) => Promise<void>
+  /** Validated DEFLATE level for session-log ZIP entries; defaults to 6. */
+  sessionExportCompressionLevel?: SessionLogCompressionLevel
   /**
    * Whether handing a path to the native opener can work at all — the
    * `hasDocument` capability the preset roster reports, and the switch
@@ -989,6 +993,8 @@ function changedWorkspaceView(workspaceId: string, value: unknown): WorkspaceVie
  * @returns the ApiProxy implementation.
  */
 export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiProxy {
+  const sessionExportCompressionLevel = defaults.sessionExportCompressionLevel
+    ?? DEFAULT_SESSION_LOG_COMPRESSION_LEVEL
   /** The seed model each create/resume declares; re-read so it never goes stale. */
   const agentOptions = (): AgentOptions => {
     const { provider, model } = defaults.defaultModelSelection()
@@ -3517,7 +3523,14 @@ export function createApiProxy(ctx: Context, defaults: ApiProxyDefaults): ApiPro
           return new Response('session not found', { status: 404 })
         }
         return new Response(
-          streamSessionLogZip(ready, root, request.sessionId, request.includeDescendants === true, signal),
+          streamSessionLogZip(
+            ready,
+            root,
+            request.sessionId,
+            request.includeDescendants === true,
+            sessionExportCompressionLevel,
+            signal,
+          ),
           {
             headers: {
               'content-type': 'application/zip',

packages/host/apiproxy/src/index.ts

@@ -17,6 +17,10 @@ import z from '@deepseek-ai/schemastery'
 import type {} from '@deepseek-ai/dsh-agent-default-model'
 import type { ApiProxy } from './api/index.ts'
 import { createApiProxy } from './api-proxy.ts'
+import {
+  DEFAULT_SESSION_LOG_COMPRESSION_LEVEL,
+  type SessionLogCompressionLevel,
+} from './session-export.ts'
 
 export type * from './api/index.ts'
 export { RpcId } from './api/rpc.ts'
@@ -33,7 +37,7 @@ declare module '@deepseek-ai/cordis' {
   }
 }
 
-/** Gateway plugin config for native Host integration. */
+/** Gateway plugin configuration. */
 export interface Config {
   /**
    * Whether this deployment can hand paths to a native desktop opener —
@@ -43,6 +47,12 @@ export interface Config {
    * container whose DISPLAY points nowhere a user can see.
    */
   nativeOpen?: boolean
+  /**
+   * DEFLATE level for every session-log ZIP entry: `0` stores without
+   * compression, `1` favors CPU/latency, and `9` favors archive size.
+   * @default 6
+   */
+  sessionExportCompressionLevel?: 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
 }
 
 /**
@@ -58,6 +68,8 @@ export class ApiProxyService extends Service implements ApiProxy {
 
   static Config: z<Config> = z.object({
     nativeOpen: z.boolean(),
+    sessionExportCompressionLevel: z.number().step(1).min(0).max(9)
+      .default(DEFAULT_SESSION_LOG_COMPRESSION_LEVEL) as z<SessionLogCompressionLevel>,
   })
 
   readonly sessions: ApiProxy['sessions']
@@ -82,6 +94,7 @@ export class ApiProxyService extends Service implements ApiProxy {
       saveDefaultModelSelection: selection => ctx.agentDefaultModel.saveSelection(selection),
       cwd: process.cwd(),
       ...config.nativeOpen === undefined ? {} : { canOpenPath: () => config.nativeOpen as boolean },
+      sessionExportCompressionLevel: config.sessionExportCompressionLevel ?? DEFAULT_SESSION_LOG_COMPRESSION_LEVEL,
     })
     this.sessions = api.sessions
     this.subagents = api.subagents

packages/host/apiproxy/src/session-export.ts

@@ -26,6 +26,12 @@ import type { SessionLineageNode, SessionQueryService } from '@deepseek-ai/dsh-s
 import type { SessionId, SessionStore } from '@deepseek-ai/dsh-session'
 import type { SessionPersistence, SessionRawArtifact } from '@deepseek-ai/dsh-session-persistence'
 
+/** Valid fflate DEFLATE levels accepted by session-log export. */
+export type SessionLogCompressionLevel = 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9
+
+/** Balanced default used when a direct createApiProxy caller omits deployment config. */
+export const DEFAULT_SESSION_LOG_COMPRESSION_LEVEL: SessionLogCompressionLevel = 6
+
 /** The services a session-log export needs (the live-session store is optional). */
 export interface SessionLogExportDeps {
   readonly sessionQuery: SessionQueryService | undefined
@@ -375,6 +381,7 @@ async function pushArtifactChunks(
  * @param root - the already-read root artifact (first zip entry).
  * @param sessionId - the root session id.
  * @param includeDescendants - whether to include every subagent descendant.
+ * @param compressionLevel - validated fflate DEFLATE level for every ZIP entry.
  * @param signal - request cancellation combined with response-consumer cancellation.
  * @returns the zip byte stream.
  */
@@ -383,6 +390,7 @@ export function streamSessionLogZip(
   root: SessionRawArtifact,
   sessionId: SessionId,
   includeDescendants: boolean,
+  compressionLevel: SessionLogCompressionLevel,
   signal: AbortSignal,
 ): ReadableStream<Uint8Array> {
   const consumerAbort = new AbortController()
@@ -415,7 +423,7 @@ export function streamSessionLogZip(
       void (async () => {
         try {
           for await (const entry of sessionLogZipEntries(deps, root, sessionId, includeDescendants, producerSignal)) {
-            const deflate = new ZipDeflate(entry.path, { level: 6 })
+            const deflate = new ZipDeflate(entry.path, { level: compressionLevel })
             archive.add(deflate)
             if ('content' in entry) {
               await pushArtifactChunks(deflate, entry.content, controller, capacity, producerSignal)