feat(dsbench): add SDK evaluation composition

packages/llm/llm-deepseek/src/adapter.ts

@@ -61,6 +61,9 @@ export class DeepSeekAdapter extends LlmAdapter {
         'content-type': 'application/json',
         'accept': 'text/event-stream',
         ...attributionHeaders(),
+        ...options.sessionId !== undefined
+          ? { 'x-deepseek-harness-session-id': String(options.sessionId) }
+          : {},
       },
       body: JSON.stringify(body),
       ...options.signal ? { signal: options.signal } : {},

packages/llm/llm-deepseek/tests/adapter.spec.ts

@@ -3,6 +3,7 @@ import type { IncomingMessage, Server, ServerResponse } from 'node:http'
 import { afterEach, describe, expect, it, vi } from 'vitest'
 import { Context } from 'cordis'
 import LlmService, { LlmError, userAgent } from '@deepseek-ai/dsh-llm'
+import { SessionId } from '@deepseek-ai/dsh-session'
 import * as LlmDeepSeek from '@deepseek-ai/dsh-llm-deepseek'
 import { DeepSeekAdapter, httpErrorCode } from '@deepseek-ai/dsh-llm-deepseek'
 import { assemble } from './assemble.ts'
@@ -131,6 +132,19 @@ describe('DeepSeekAdapter against a mock server', () => {
     expect(kinds).toEqual(['block-start', 'text-delta', 'block-end', 'usage', 'finish'])
   })
 
+  it('forwards the harness session id for host-side trajectory routing', async () => {
+    const server = await mockServer([{ kind: 'sse', events: textEvents }])
+    const ctx = await harness(server.url)
+
+    await assemble(ctx, {
+      model: 'deepseek-v4-flash',
+      messages: [{ role: 'user', content: [{ type: 'text', text: 'hi' }] }],
+      sessionId: SessionId('child-session'),
+    })
+
+    expect(server.headers[0]?.['x-deepseek-harness-session-id']).toBe('child-session')
+  })
+
   it('forwards thinking config onto the wire', async () => {
     const server = await mockServer([{ kind: 'sse', events: textEvents }])
     const ctx = await harness(server.url, { thinking: 'disabled', reasoningEffort: 'high' })