{
  "$schema": "https://themachinepress.com/schemas/story-v1.schema.json",
  "schema_version": "1.0.0",
  "document_type": "machine_press_story",
  "story": {
    "story_id": "mp-2026-08-26-026",
    "source_story_id": "tmp-story-agent-harness-convergence",
    "edition_id": "mp-2026-08-26-morning-0048",
    "edition_url": "https://themachinepress.com/edition/2026-08-26",
    "position": 15,
    "story_type": "dispatch",
    "section": "developer-tools",
    "editorial_classification": "editorial",
    "headline": "Three Agent Harnesses Converged on Five Pieces—and Missed the Sixth",
    "slug": "three-agent-harnesses-converged-on-five-pieces-and-missed-the-sixth",
    "dek": "A source-level case study finds replayable sessions, model quirks as data, progressive context and extension seams across opposing designs.",
    "summary": "A source-level case study finds replayable sessions, model quirks as data, progressive context and extension seams across opposing designs.",
    "body_text": "The authors trace convergence through parallel discovery, diffusion and direct reuse rather than claiming independent invention. All three examined coding-agent harnesses showed the five recurring elements, while none supplied an externally verifiable, tamper-evident record that an outside party could check without trusting the runtime.",
    "why_it_matters": "A source-level case study finds replayable sessions, model quirks as data, progressive context and extension seams across opposing designs.",
    "limitations": [],
    "importance": 8,
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-26-026/three-agent-harnesses-converged-on-five-pieces-and-missed-the-sixth",
    "json_url": "https://themachinepress.com/story/mp-2026-08-26-026.json",
    "first_published_at": "2026-08-26T09:00:00.000-04:00",
    "modified_at": "2026-08-26T09:00:00.000-04:00",
    "content_status": "new",
    "is_carryover": false,
    "carryover_reason": null,
    "key_claims": [
      {
        "claim_id": "claim-mp-2026-08-26-026-001",
        "text": "A source-level case study finds replayable sessions, model quirks as data, progressive context and extension seams across opposing designs.",
        "source_ids": [
          "source-2026-08-26-015"
        ],
        "qualification": null
      }
    ],
    "source_ids": [
      "source-2026-08-26-015"
    ],
    "tags": [
      "agent harnesses",
      "software architecture",
      "provenance"
    ],
    "image_url": null,
    "corrections": []
  },
  "sources": [
    {
      "source_id": "source-2026-08-26-015",
      "title": "arXiv preprint 2608.23953",
      "publisher": "arXiv",
      "url": "https://arxiv.org/abs/2608.23953",
      "canonical_url": "https://arxiv.org/abs/2608.23953",
      "source_type": "primary_research",
      "is_primary_source": true,
      "published_at": "2026-08-24T21:26:41.000-04:00",
      "accessed_at": "2026-08-26T08:17:00.000-04:00",
      "supports_claim_ids": [
        "claim-mp-2026-08-26-026-001"
      ]
    }
  ],
  "corrections": [],
  "publisher": {
    "name": "The Machine Press",
    "url": "https://themachinepress.com",
    "description": "A daily newspaper for the age of artificial intelligence."
  },
  "cite_this_report": {
    "title": "Three Agent Harnesses Converged on Five Pieces—and Missed the Sixth",
    "publisher": "The Machine Press",
    "published_at": "2026-08-26T09:00:00.000-04:00",
    "canonical_url": "https://themachinepress.com/story/mp-2026-08-26-026/three-agent-harnesses-converged-on-five-pieces-and-missed-the-sixth"
  }
}