Devtools streamCapture endpoints do not capture events for Next.js dynamic routes matching a stable substring

[siddharthsharma94]

Issue Summary

Problem: streamCapture with the endpoints array does not capture events from Next.js dynamic routes, even when a stable substring pattern (per documentation) is used.

I'm struggling to figure out how to get dynamic events to show up

Technical Details

Setup:

• Next.js Route: app/api/a/games/[gameId]/chat/route.ts
• Runtime URL Example: /api/a/games/${gameId}/chat (e.g., /api/a/games/game_ZUWAFrQKmL/chat)
• Transport Config:

  transport: new DefaultChatTransport({
    api: `/api/a/games/${gameId}/chat`
  })

• Devtools Config:

  streamCapture={{
    enabled: true,
    endpoints: ["/api/a/games"], // Stable substring per docs
    autoConnect: true,
  }}

Expected Behavior (per docs):

• Substring matching: /api/a/games should match /api/a/games/game_ZUWAFrQKmL/chat
• The interceptor should patch window.fetch and capture streaming events

Actual Behavior:

• State tracking works (messages, status)
• Events/tools are not captured
• onEvent callback never fires
• No events appear in devtools panel

What Works:

• Static route /api/chat works with endpoints: ["/api/chat"]
• State management via @ai-sdk-tools/store works correctly
  This worked for me

const { messages, sendMessage, status } = useChat({
    transport: new DefaultChatTransport({
      // api: `/api/a/games/${gameId}/chat`, <--- uncommenting this does not work 
      body: {
        gameId,
      },
    }),
  });

So if the route is not dynamic events show up fine.

Environment:

• Next.js 16.0.0 (App Router)
• @ai-sdk-tools/devtools latest
• @ai-sdk-tools/store latest
• Using DefaultChatTransport from ai package

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This issue contains enough context and reproduction steps to assist with investigation. Please advise on substring matching for dynamic routes and any known compatibility caveats.