Result Format

Every Lace executor returns a ProbeResult -- a single JSON object that captures the complete outcome of a probe run: timing, per-call details, assertion verdicts, and write-back actions.

The schema is defined in schemas/result.json and specified in lace-spec.md section 9.

---

Top-level fields

All seven fields are required and always present.

Field	Type	Description
outcome	string	Overall run result: "success", "failure", or "timeout".
startedAt	string (ISO 8601)	UTC timestamp taken before the first call begins.
endedAt	string (ISO 8601)	UTC timestamp taken after all chain methods complete or the failure cascade stops.
elapsedMs	integer	Wall-clock elapsed time in milliseconds (endedAt - startedAt).
runVars	object	Final state of all $$var assignments. Each key appears at most once (write-once rule). Extension-emitted variables use a {extension_name}. prefix.
calls	array	Ordered call records, including skipped calls.
actions	object	Action map. actions.variables is always present. Extensions may add additional arrays. See Actions.

---

Outcome values

Value	Meaning
"success"	Every call completed and all hard assertions (.expect()) passed.
"failure"	At least one hard assertion failed or a non-assertion error occurred (connection refused, body too large, redirect limit exceeded).
"timeout"	The run exceeded the configured timeout before completing.

---

Minimal complete example

A probe with a single GET call, one status assertion, and no stored variables:

CompactFull

{
  "outcome": "success",
  "startedAt": "2024-01-15T14:23:01.234Z",
  "endedAt": "2024-01-15T14:23:02.891Z",
  "elapsedMs": 1657,
  "runVars": {},
  "calls": [
    {
      "index": 0,
      "outcome": "success",
      "request": {
        "url": "https://api.example.com/health",
        "method": "get"
      },
      "response": {
        "status": 200,
        "statusText": "OK",
        "responseTimeMs": 145
      },
      "assertions": [
        {
          "method": "expect",
          "scope": "status",
          "outcome": "passed"
        }
      ]
    }
  ],
  "actions": {
    "variables": {}
  }
}

{
  "outcome": "success",
  "startedAt": "2024-01-15T14:23:01.234Z",
  "endedAt": "2024-01-15T14:23:02.891Z",
  "elapsedMs": 1657,
  "runVars": {},
  "calls": [
    {
      "index": 0,
      "outcome": "success",
      "startedAt": "2024-01-15T14:23:01.234Z",
      "endedAt": "2024-01-15T14:23:02.891Z",
      "request": {
        "url": "https://api.example.com/health",
        "method": "get",
        "headers": {
          "user-agent": "Lace/0.9"
        },
        "bodyPath": null
      },
      "response": {
        "status": 200,
        "statusText": "OK",
        "headers": {
          "content-type": "application/json",
          "x-request-id": "req-78f3a"
        },
        "bodyPath": "/probe_runs/abc/call_0_response.json",
        "responseTimeMs": 145,
        "dnsMs": 12,
        "connectMs": 34,
        "tlsMs": 28,
        "ttfbMs": 98,
        "transferMs": 47,
        "sizeBytes": 256,
        "dns": {
          "resolvedIps": [
            "93.184.216.34"
          ],
          "resolvedIp": "93.184.216.34"
        },
        "tls": {
          "protocol": "TLSv1.3",
          "cipher": "TLS_AES_256_GCM_SHA384",
          "alpn": "h2",
          "certificate": {
            "subject": {
              "cn": "api.example.com"
            },
            "subjectAltNames": [
              "DNS:api.example.com"
            ],
            "issuer": {
              "cn": "R3"
            },
            "notBefore": "2024-01-01T00:00:00Z",
            "notAfter": "2024-07-01T00:00:00Z"
          }
        }
      },
      "redirects": [],
      "assertions": [
        {
          "method": "expect",
          "scope": "status",
          "op": "eq",
          "outcome": "passed",
          "actual": 200,
          "expected": 200,
          "options": null
        }
      ],
      "config": {
        "timeout": {
          "ms": 5000,
          "action": "fail",
          "retries": 0
        },
        "redirects": {
          "follow": true,
          "max": 10
        },
        "security": {
          "rejectInvalidCerts": true
        }
      },
      "warnings": [],
      "error": null
    }
  ],
  "actions": {
    "variables": {}
  }
}

---

Sub-pages

Page	Contents
Call Record	Per-call fields, request/response records, assertions.
Response Metadata	DNS, TLS, redirect tracking, and timing breakdown.
Body Storage	How request/response bodies are stored as files.
Actions	Write-back variables and extension-defined action arrays.