feat: enhance user ID parsing with JSON support and legacy fallback

Author: caozhiyuan

src/lib/utils.ts

@@ -115,6 +115,50 @@ interface PayloadMessage {
   type?: string
 }
 
+const isRecord = (value: unknown): value is Record<string, unknown> =>
+  typeof value === "object" && value !== null
+
+const getUserIdJsonField = (
+  userIdPayload: Record<string, unknown> | null,
+  field: string,
+): string | null => {
+  const value = userIdPayload?.[field]
+  return typeof value === "string" && value.length > 0 ? value : null
+}
+
+const parseJsonUserId = (userId: string): Record<string, unknown> | null => {
+  try {
+    const parsed: unknown = JSON.parse(userId)
+    return isRecord(parsed) ? parsed : null
+  } catch {
+    return null
+  }
+}
+
+export const parseUserIdMetadata = (
+  userId: string | undefined,
+): { safetyIdentifier: string | null; sessionId: string | null } => {
+  if (!userId || typeof userId !== "string") {
+    return { safetyIdentifier: null, sessionId: null }
+  }
+
+  const legacySafetyIdentifier =
+    userId.match(/user_([^_]+)_account/)?.[1] ?? null
+  const legacySessionId = userId.match(/_session_(.+)$/)?.[1] ?? null
+
+  const parsedUserId =
+    legacySafetyIdentifier && legacySessionId ? null : parseJsonUserId(userId)
+
+  const safetyIdentifier =
+    legacySafetyIdentifier
+    ?? getUserIdJsonField(parsedUserId, "device_id")
+    ?? getUserIdJsonField(parsedUserId, "account_uuid")
+  const sessionId =
+    legacySessionId ?? getUserIdJsonField(parsedUserId, "session_id")
+
+  return { safetyIdentifier, sessionId }
+}
+
 const findLastUserContent = (
   messages: Array<PayloadMessage>,
 ): string | null => {
@@ -161,19 +205,13 @@ export const getRootSessionId = (
   anthropicPayload: AnthropicMessagesPayload,
   c: Context,
 ): string | undefined => {
-  let sessionId: string | undefined
-  if (anthropicPayload.metadata?.user_id) {
-    const sessionMatch = new RegExp(/_session_(.+)$/).exec(
-      anthropicPayload.metadata.user_id,
-    )
-    sessionId = sessionMatch ? sessionMatch[1] : undefined
-  } else {
-    sessionId = c.req.header("x-session-id")
-  }
-  if (sessionId) {
-    return getUUID(sessionId)
-  }
-  return sessionId
+  const userId = anthropicPayload.metadata?.user_id
+  const sessionId =
+    userId ?
+      parseUserIdMetadata(userId).sessionId || undefined
+    : c.req.header("x-session-id")
+
+  return sessionId ? getUUID(sessionId) : sessionId
 }
 
 export const getUUID = (content: string): string => {

src/routes/messages/responses-translation.ts

@@ -4,6 +4,7 @@ import {
   getExtraPromptForModel,
   getReasoningEffortForModel,
 } from "~/lib/config"
+import { parseUserIdMetadata } from "~/lib/utils"
 import {
   type ResponsesPayload,
   type ResponseInputCompaction,
@@ -64,7 +65,7 @@ export const translateAnthropicMessagesToResponsesPayload = (
   const translatedTools = convertAnthropicTools(payload.tools)
   const toolChoice = convertAnthropicToolChoice(payload.tool_choice)
 
-  const { safetyIdentifier, promptCacheKey } = parseUserId(
+  const { safetyIdentifier, sessionId: promptCacheKey } = parseUserIdMetadata(
     payload.metadata?.user_id,
   )
 
@@ -751,24 +752,6 @@ const isResponseOutputRefusal = (
   && "type" in block
   && (block as { type?: unknown }).type === "refusal"
 
-const parseUserId = (
-  userId: string | undefined,
-): { safetyIdentifier: string | null; promptCacheKey: string | null } => {
-  if (!userId || typeof userId !== "string") {
-    return { safetyIdentifier: null, promptCacheKey: null }
-  }
-
-  // Parse safety_identifier: content between "user_" and "_account"
-  const userMatch = userId.match(/user_([^_]+)_account/)
-  const safetyIdentifier = userMatch ? userMatch[1] : null
-
-  // Parse prompt_cache_key: content after "_session_"
-  const sessionMatch = userId.match(/_session_(.+)$/)
-  const promptCacheKey = sessionMatch ? sessionMatch[1] : null
-
-  return { safetyIdentifier, promptCacheKey }
-}
-
 const convertToolResultContent = (
   content: string | Array<AnthropicTextBlock | AnthropicImageBlock>,
 ): string | Array<ResponseInputContent> => {

tests/responses-translation.test.ts

@@ -46,6 +46,15 @@ const samplePayload = {
   ],
 } as unknown as AnthropicMessagesPayload
 
+const jsonStyleUserId = JSON.stringify({
+  device_id: "3f4a1b7c8d9e0f1234567890abcdef1234567890abcdef1234567890abcdef12",
+  account_uuid: "",
+  session_id: "2c4e1cf0-7a67-4d2e-9a4b-1d16d3f44752",
+})
+
+const legacyStyleUserId =
+  "user_8b7e2c1d4f6a9b3c0d1e2f3456789abcdeffedcba9876543210fedcba1234567_account__session_7d0e2f61-4b5c-4a9d-8f11-2c3d4e5f6a7b"
+
 describe("translateAnthropicMessagesToResponsesPayload", () => {
   it("converts anthropic text blocks into response input messages", () => {
     const result = translateAnthropicMessagesToResponsesPayload(samplePayload)
@@ -67,6 +76,34 @@ describe("translateAnthropicMessagesToResponsesPayload", () => {
       "hi",
     ])
   })
+
+  it("extracts identifiers from JSON-like user_id metadata", () => {
+    const result = translateAnthropicMessagesToResponsesPayload({
+      ...samplePayload,
+      metadata: {
+        user_id: jsonStyleUserId,
+      },
+    })
+
+    expect(result.safety_identifier).toBe(
+      "3f4a1b7c8d9e0f1234567890abcdef1234567890abcdef1234567890abcdef12",
+    )
+    expect(result.prompt_cache_key).toBe("2c4e1cf0-7a67-4d2e-9a4b-1d16d3f44752")
+  })
+
+  it("keeps legacy user_id parsing before JSON fallback", () => {
+    const result = translateAnthropicMessagesToResponsesPayload({
+      ...samplePayload,
+      metadata: {
+        user_id: legacyStyleUserId,
+      },
+    })
+
+    expect(result.safety_identifier).toBe(
+      "8b7e2c1d4f6a9b3c0d1e2f3456789abcdeffedcba9876543210fedcba1234567",
+    )
+    expect(result.prompt_cache_key).toBe("7d0e2f61-4b5c-4a9d-8f11-2c3d4e5f6a7b")
+  })
 })
 
 describe("translateResponsesResultToAnthropic", () => {

tests/utils.test.ts

@@ -1,7 +1,20 @@
+import type { Context } from "hono"
+
 import { expect, test } from "bun:test"
 import { createHash, randomUUID } from "node:crypto"
 
-import { getUUID } from "../src/lib/utils"
+import type { AnthropicMessagesPayload } from "~/routes/messages/anthropic-types"
+
+import { getRootSessionId, getUUID } from "../src/lib/utils"
+
+const jsonStyleUserId = JSON.stringify({
+  device_id: "3f4a1b7c8d9e0f1234567890abcdef1234567890abcdef1234567890abcdef12",
+  account_uuid: "",
+  session_id: "2c4e1cf0-7a67-4d2e-9a4b-1d16d3f44752",
+})
+
+const legacyStyleUserId =
+  "user_8b7e2c1d4f6a9b3c0d1e2f3456789abcdeffedcba9876543210fedcba1234567_account__session_7d0e2f61-4b5c-4a9d-8f11-2c3d4e5f6a7b"
 
 const getLegacyUUID = (content: string): string => {
   const hash32 = createHash("sha256").update(content).digest("hex").slice(0, 32)
@@ -43,3 +56,43 @@ test("prints randomUUID and deterministic UUID for comparison", () => {
   expect(legacy).not.toBe(derived)
   expect(random).not.toBe(derived)
 })
+
+test("getRootSessionId supports JSON-like user_id metadata", () => {
+  const anthropicPayload = {
+    model: "claude-3-5-sonnet",
+    messages: [],
+    max_tokens: 0,
+    metadata: {
+      user_id: jsonStyleUserId,
+    },
+  } as AnthropicMessagesPayload
+  const context = {
+    req: {
+      header: (_name: string) => undefined,
+    },
+  } as unknown as Context
+
+  expect(getRootSessionId(anthropicPayload, context)).toBe(
+    getUUID("2c4e1cf0-7a67-4d2e-9a4b-1d16d3f44752"),
+  )
+})
+
+test("getRootSessionId keeps legacy parsing before JSON fallback", () => {
+  const anthropicPayload = {
+    model: "claude-3-5-sonnet",
+    messages: [],
+    max_tokens: 0,
+    metadata: {
+      user_id: legacyStyleUserId,
+    },
+  } as AnthropicMessagesPayload
+  const context = {
+    req: {
+      header: (_name: string) => undefined,
+    },
+  } as unknown as Context
+
+  expect(getRootSessionId(anthropicPayload, context)).toBe(
+    getUUID("7d0e2f61-4b5c-4a9d-8f11-2c3d4e5f6a7b"),
+  )
+})