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    "story_id": "mp-2026-09-19-003",
    "source_story_id": "tmp-story-solpi-harness-token-efficiency",
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    "section": "developer-tools",
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    "headline": "The Agent Harness Cut Token Traffic Almost in Half",
    "slug": "the-agent-harness-cut-token-traffic-almost-in-half",
    "dek": "SoL-Pi matched its comparison harness while reducing recorded token traffic 44.7% to 49.0%.",
    "summary": "SoL-Pi matched its comparison harness while reducing recorded token traffic 44.7% to 49.0%.",
    "body_text": "The SoL-Pi team scaled automated harness experiments across many environments, then retained four mechanisms covering action execution, context compaction, observation handling and delegated reading. On the 51-task EdgeBench evaluation, the resulting harness performed comparably to Pi across GPT-5.6 Sol and Opus 5 while cutting recorded token traffic by 44.7% to 49.0% and reported API cost by about one third. The savings are evaluation estimates from the tested models, prices and tasks, not a universal operating-cost guarantee.",
    "why_it_matters": "SoL-Pi matched its comparison harness while reducing recorded token traffic 44.7% to 49.0%.",
    "limitations": [
      "The savings are evaluation estimates from the tested models, prices and tasks, not a universal operating-cost guarantee."
    ],
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    "first_published_at": "2026-09-19T09:00:00.000-04:00",
    "modified_at": "2026-09-19T09:00:00.000-04:00",
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        "text": "SoL-Pi matched its comparison harness while reducing recorded token traffic 44.7% to 49.0%.",
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        "qualification": "The savings are evaluation estimates from the tested models, prices and tasks, not a universal operating-cost guarantee."
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    "tags": [
      "coding agents",
      "agent harnesses",
      "token efficiency"
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    {
      "source_id": "source-2026-09-19-003",
      "title": "arXiv preprint 2609.20519",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2609.20519",
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      "published_at": "2026-09-17T10:58:29.000-04:00",
      "accessed_at": "2026-09-19T08:30:21.326-04:00",
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  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
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  "cite_this_report": {
    "title": "The Agent Harness Cut Token Traffic Almost in Half",
    "publisher": "The Machine Press",
    "published_at": "2026-09-19T09:00:00.000-04:00",
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