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  "story": {
    "story_id": "mp-2026-09-08-013",
    "source_story_id": "tmp-story-agent-memory-model-upgrade",
    "edition_id": "mp-2026-09-08-morning-0061",
    "edition_url": "https://themachinepress.com/edition/2026-09-08",
    "position": 13,
    "story_type": "dispatch",
    "section": "developer-tools",
    "editorial_classification": "editorial",
    "headline": "The Memory Store Stayed. The Upgraded Agent Still Forgot",
    "slug": "the-memory-store-stayed-the-upgraded-agent-still-forgot",
    "dek": "Fixed-schema knowledge graphs transferred almost unchanged, while compressed notes swung by as much as 13.28 points depending on migration direction.",
    "summary": "Fixed-schema knowledge graphs transferred almost unchanged, while compressed notes swung by as much as 13.28 points depending on migration direction.",
    "body_text": "The controlled study preserved the same 48 synthetic histories across long-context reading, retrieval chunks, model-compressed notes and fixed-schema knowledge graphs, then changed the sub-10-billion-parameter model reading or writing them. Fixed-schema graph accuracy changed by only 0.0004 points, within a 0.0020 uncertainty band. Compressed notes moved asymmetrically by plus 9.91 or minus 13.28 percentage points depending on direction. A half-migrated embedding index captured only 4.96 points of the 11.90-point gain from full re-embedding. Repairing notes without raw history never reached the 90-percent recovery target, while keeping source history succeeded in 34 of 48 cases in one direction.",
    "why_it_matters": "Fixed-schema knowledge graphs transferred almost unchanged, while compressed notes swung by as much as 13.28 points depending on migration direction.",
    "limitations": [
      "Fixed-schema graph accuracy changed by only 0.0004 points, within a 0.0020 uncertainty band.",
      "A half-migrated embedding index captured only 4.96 points of the 11.90-point gain from full re-embedding."
    ],
    "importance": 9,
    "canonical_url": "https://themachinepress.com/story/mp-2026-09-08-013/the-memory-store-stayed-the-upgraded-agent-still-forgot",
    "json_url": "https://themachinepress.com/story/mp-2026-09-08-013.json",
    "first_published_at": "2026-09-08T09:00:00.000-04:00",
    "modified_at": "2026-09-08T09:00:00.000-04:00",
    "content_status": "new",
    "is_carryover": false,
    "carryover_reason": null,
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        "text": "Fixed-schema knowledge graphs transferred almost unchanged, while compressed notes swung by as much as 13.28 points depending on migration direction.",
        "source_ids": [
          "source-2026-09-08-013"
        ],
        "qualification": "Fixed-schema graph accuracy changed by only 0.0004 points, within a 0.0020 uncertainty band."
      }
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    "source_ids": [
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    "tags": [
      "agent memory",
      "model migration",
      "retrieval"
    ],
    "image_url": "https://themachinepress.com/issues/2026-09-08/memory-migration-data-center-file.webp",
    "corrections": []
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  "sources": [
    {
      "source_id": "source-2026-09-08-013",
      "title": "arXiv preprint 2609.05339",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.05339",
      "canonical_url": "https://arxiv.org/abs/2609.05339",
      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-09-04T12:44:17.000-04:00",
      "accessed_at": "2026-09-08T08:20:00.000-04:00",
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  "corrections": [],
  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
  },
  "cite_this_report": {
    "title": "The Memory Store Stayed. The Upgraded Agent Still Forgot",
    "publisher": "The Machine Press",
    "published_at": "2026-09-08T09:00:00.000-04:00",
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