{
  "id": "streaming-answer-recovery",
  "title": "Streaming Answer Recovery",
  "tagline": "Reconnect a streamed answer without duplicating text or hiding an incomplete result.",
  "summary": "Build a browser answer view and local event stream for developers integrating assistant output. Handle split UTF-8 bytes, event IDs, reconnection, cancellation and partial citations. Preserve the difference between an interrupted draft and a completed answer, with a downloadable event trace to reproduce rendering failures.",
  "level": 3,
  "source": "core",
  "status": "ready",
  "hours": 8,
  "languages": [
    "TypeScript",
    "Go"
  ],
  "author": {
    "name": "AI Engineering from Scratch",
    "github": "rohitg00"
  },
  "youWillBuild": "Reusable browser component, SSE fixture server and replayable event trace",
  "prerequisiteProjects": [
    "agent-trace-debugger",
    "json-schema-output-guard"
  ],
  "demo": {
    "command": [
      "python3",
      "demo.py"
    ],
    "cwd": "solution"
  },
  "stages": [
    {
      "id": "01-decode-sse",
      "title": "Decode chunked bytes into complete events",
      "summary": "Let UTF-8 and SSE framing survive arbitrary transport boundaries.",
      "hours": 2,
      "language": "typescript",
      "difficulty": "starter",
      "concepts": [
        "TextDecoder",
        "SSE framing",
        "persistent ID"
      ],
      "timeout": 120,
      "figure": "pj-streaming-answer-recovery-1"
    },
    {
      "id": "02-stable-answer-state",
      "title": "Render text and citations by stable identity",
      "summary": "Make duplicate delivery harmless while preserving incomplete state.",
      "hours": 2,
      "language": "typescript",
      "difficulty": "core",
      "concepts": [
        "event identity",
        "deduplication",
        "partial citations"
      ],
      "timeout": 120,
      "figure": "pj-streaming-answer-recovery-2"
    },
    {
      "id": "03-reconnect-and-cancel",
      "title": "Handle reconnect and cancellation",
      "summary": "Resume after the last accepted event, not the last partial byte.",
      "hours": 2,
      "language": "typescript+go",
      "difficulty": "core",
      "concepts": [
        "Last-Event-ID",
        "HTTP fixture",
        "AbortSignal"
      ],
      "timeout": 120,
      "figure": "pj-streaming-answer-recovery-3",
      "runners": [
        {
          "language": "typescript"
        },
        {
          "language": "go"
        }
      ]
    },
    {
      "id": "04-trace-and-component",
      "title": "Export and replay an interrupted-answer trace",
      "summary": "Ship the browser component with a replayable accepted-event artifact.",
      "hours": 2,
      "language": "typescript",
      "difficulty": "core",
      "concepts": [
        "trace schema",
        "browser component",
        "download"
      ],
      "timeout": 120,
      "figure": "pj-streaming-answer-recovery-4"
    }
  ],
  "demos": [
    {
      "gif": "media/run.gif",
      "poster": "media/run.png",
      "title": "Initialize and grade",
      "caption": "Recorded starter failure followed by every reference stage passing."
    },
    {
      "gif": "media/output.gif",
      "poster": "media/output.png",
      "title": "Inspect actual output",
      "caption": "Recorded interaction with the generated local interface. Run the documented command to inspect your own output."
    }
  ]
}