{
 "trial": "Does schema-valid JSON extraction also say the right thing",
 "claude_code": "2.1.226",
 "date": "2026-08-10",
 "note": "Plain prompting, NOT the API constrained-decoding path. This is what a Claude Code user gets by asking for JSON and validating it themselves.",
 "schema": {
  "type": "object",
  "additionalProperties": false,
  "required": [
   "currency",
   "customer_vat_number",
   "due_date",
   "invoice_number",
   "line_item_count",
   "status",
   "total_amount"
  ],
  "properties": {
   "invoice_number": {
    "type": "string"
   },
   "total_amount": {
    "type": "number"
   },
   "currency": {
    "type": "string",
    "enum": [
     "USD",
     "EUR",
     "GBP"
    ]
   },
   "status": {
    "type": "string",
    "enum": [
     "paid",
     "unpaid",
     "overdue"
    ]
   },
   "line_item_count": {
    "type": "integer"
   },
   "due_date": {
    "type": "string",
    "pattern": "^\\d{4}-\\d{2}-\\d{2}$"
   },
   "customer_vat_number": {
    "type": [
     "string",
     "null"
    ]
   }
  }
 },
 "expected": {
  "invoice_number": "INV-2026-0473",
  "total_amount": 1284.5,
  "currency": "GBP",
  "status": "paid",
  "line_item_count": 3,
  "due_date": "2026-06-30",
  "customer_vat_number": null
 },
 "documents": {
  "clean": "INVOICE\n\nReference: INV-2026-0473\nIssued by: Northgate Supplies Ltd\nBill to: Harrow Analytics\n\nItems\n  1. Steel brackets, 40 units .......... \u00a3412.00\n  2. Mounting rail, 12m ................ \u00a3338.50\n  3. Fixing kit, 8 boxes ............... \u00a3534.00\n\nTotal due: \u00a31,284.50\n\nPayment received in full on 12 June 2026, with thanks.\nTerms: payment was due by 30 June 2026.\n",
  "noisy": "NORTHGATE SUPPLIES LTD\nNorthgate VAT registration: GB447221904\n\nSupersedes proforma INV-2026-0119 issued 04 May 2026.\nOriginal quotation was USD 1,640.00 before the GBP contract was agreed.\n\nINVOICE\n\nReference: INV-2026-0473\nBill to: Harrow Analytics\n\nItems\n  1. Steel brackets, 40 units .......... \u00a3412.00\n  2. Mounting rail, 12m ................ \u00a3338.50\n  3. Fixing kit, 8 boxes ............... \u00a3534.00\n\nTotal due: \u00a31,284.50\n\nPayment received in full on 12 June 2026, with thanks.\nTerms: payment was due by 30 June 2026.\nNext scheduled delivery: 15 August 2026.\n"
 },
 "traps": {
  "total_amount": "written with a thousands separator, must not survive as a string",
  "currency": "only a symbol appears; the enum has no symbol member",
  "status": "stated in prose (payment received in full), never as a status word",
  "line_item_count": "never stated, must be counted",
  "due_date": "written as 30 June 2026, schema demands ISO",
  "customer_vat_number": "REQUIRED by the schema and ABSENT from the document. Only null is correct. The noisy document places a VAT number for the WRONG party three lines above.",
  "additionalProperties": "false, so any invented key fails the shape check"
 },
 "scorer_controls": "Eight synthetic objects checked before any run was scored, including a schema-valid hallucination (invented VAT) which must score shape=valid, truth=wrong.",
 "runs": [
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "clean",
   "round": 0,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "clean",
   "round": 1,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "clean",
   "round": 2,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "clean",
   "round": 3,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "clean",
   "round": 4,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "clean",
   "round": 5,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "noisy",
   "round": 0,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "noisy",
   "round": 1,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "noisy",
   "round": 2,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "noisy",
   "round": 3,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "noisy",
   "round": 4,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-haiku-4-5-20251001",
   "arm": "noisy",
   "round": 5,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "```json\n{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}\n```"
  },
  {
   "model": "claude-opus-5",
   "arm": "clean",
   "round": 0,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "clean",
   "round": 1,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "clean",
   "round": 2,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "clean",
   "round": 3,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "clean",
   "round": 4,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\"invoice_number\": \"INV-2026-0473\", \"total_amount\": 1284.50, \"currency\": \"GBP\", \"status\": \"paid\", \"line_item_count\": 3, \"due_date\": \"2026-06-30\", \"customer_vat_number\": null}"
  },
  {
   "model": "claude-opus-5",
   "arm": "clean",
   "round": 5,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "noisy",
   "round": 0,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "noisy",
   "round": 1,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\"invoice_number\": \"INV-2026-0473\", \"total_amount\": 1284.50, \"currency\": \"GBP\", \"status\": \"paid\", \"line_item_count\": 3, \"due_date\": \"2026-06-30\", \"customer_vat_number\": null}"
  },
  {
   "model": "claude-opus-5",
   "arm": "noisy",
   "round": 2,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "noisy",
   "round": 3,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "noisy",
   "round": 4,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  },
  {
   "model": "claude-opus-5",
   "arm": "noisy",
   "round": 5,
   "status": "ok",
   "shape_valid": true,
   "schema_errors": [],
   "field_ok": {
    "invoice_number": true,
    "total_amount": true,
    "currency": true,
    "status": true,
    "line_item_count": true,
    "due_date": true,
    "customer_vat_number": true
   },
   "wrong": [],
   "all_fields_correct": true,
   "obj": {
    "invoice_number": "INV-2026-0473",
    "total_amount": 1284.5,
    "currency": "GBP",
    "status": "paid",
    "line_item_count": 3,
    "due_date": "2026-06-30",
    "customer_vat_number": null
   },
   "reply": "{\n  \"invoice_number\": \"INV-2026-0473\",\n  \"total_amount\": 1284.50,\n  \"currency\": \"GBP\",\n  \"status\": \"paid\",\n  \"line_item_count\": 3,\n  \"due_date\": \"2026-06-30\",\n  \"customer_vat_number\": null\n}"
  }
 ]
}