{
  "url": "https://www.tax.service.gov.uk",
  "auditedAt": "2026-07-22T11:42:31.501Z",
  "mode": "report",
  "status": "completed",
  "statusDetail": "The requested URL redirects to the public HMRC organisation page on GOV.UK; the audit followed that entry point into representative HMRC information and unauthenticated support routes.",
  "page": {
    "appType": "hybrid",
    "framework": "Server-rendered GOV.UK publishing pages plus an HMRC chat client",
    "notes": "Representative coverage includes organisation, guidance, selector, live chat and 404 archetypes. Authenticated tax-account screens and transactions requiring personal credentials were not covered."
  },
  "evidenceUsed": [
    "screenshot",
    "dom",
    "layout-metrics",
    "evaluate-probe",
    "trace",
    "har",
    "discoverability",
    "headers",
    "cookies",
    "trackers",
    "secrets",
    "images",
    "heap-summary",
    "lighthouse"
  ],
  "guidanceConsulted": [
    "dark-mode",
    "accessibility",
    "optimize-image-priority",
    "visually-stable-font-fallbacks",
    "identify-heavy-scripts",
    "security",
    "privacy",
    "forms",
    "improve-text-layout-and-legibility",
    "performance",
    "html"
  ],
  "artifacts": [
    {
      "type": "other",
      "path": "evidence/assistant-cookies.json",
      "caption": "assistant cookies",
      "findingIds": [
        "F6"
      ]
    },
    {
      "type": "screenshot",
      "path": "evidence/assistant-discoverability-crawler.png",
      "caption": "assistant discoverability crawler"
    },
    {
      "type": "screenshot",
      "path": "evidence/assistant-discoverability-rendered.png",
      "caption": "assistant discoverability rendered"
    },
    {
      "type": "discoverability",
      "path": "evidence/assistant-discoverability.json",
      "caption": "assistant discoverability"
    },
    {
      "type": "dom",
      "path": "evidence/assistant-dom.json",
      "caption": "assistant dom"
    },
    {
      "type": "other",
      "path": "evidence/assistant-headers.json",
      "caption": "assistant headers",
      "findingIds": [
        "F7"
      ]
    },
    {
      "type": "heap",
      "path": "evidence/assistant-heap-baseline.json",
      "caption": "assistant heap baseline"
    },
    {
      "type": "heap",
      "path": "evidence/assistant-heap-post.json",
      "caption": "assistant heap post"
    },
    {
      "type": "layout",
      "path": "evidence/assistant-layout.json",
      "caption": "assistant layout"
    },
    {
      "type": "screenshot",
      "path": "evidence/assistant-mobile.png",
      "caption": "assistant mobile",
      "condition": "viewport: 360x800"
    },
    {
      "type": "other",
      "path": "evidence/assistant-probe.json",
      "caption": "assistant probe"
    },
    {
      "type": "har-summary",
      "path": "evidence/assistant-summary.json",
      "caption": "assistant summary",
      "findingIds": [
        "F4"
      ]
    },
    {
      "type": "har",
      "path": "evidence/assistant.har",
      "caption": "assistant"
    },
    {
      "type": "screenshot",
      "path": "evidence/chat-empty-submit.png",
      "caption": "chat empty submit"
    },
    {
      "type": "other",
      "path": "evidence/chat-error-probe.json",
      "caption": "chat error probe"
    },
    {
      "type": "heap",
      "path": "evidence/chat-heap-baseline.json",
      "caption": "chat heap baseline"
    },
    {
      "type": "heap",
      "path": "evidence/chat-heap-post.json",
      "caption": "chat heap post"
    },
    {
      "type": "other",
      "path": "evidence/chat-probe.json",
      "caption": "chat probe"
    },
    {
      "type": "screenshot",
      "path": "evidence/chat-self-assessment-discoverability-crawler.png",
      "caption": "chat self assessment discoverability crawler"
    },
    {
      "type": "screenshot",
      "path": "evidence/chat-self-assessment-discoverability-rendered.png",
      "caption": "chat self assessment discoverability rendered"
    },
    {
      "type": "discoverability",
      "path": "evidence/chat-self-assessment-discoverability.json",
      "caption": "chat self assessment discoverability"
    },
    {
      "type": "dom",
      "path": "evidence/chat-self-assessment-dom.json",
      "caption": "chat self assessment dom"
    },
    {
      "type": "layout",
      "path": "evidence/chat-self-assessment-layout.json",
      "caption": "chat self assessment layout"
    },
    {
      "type": "screenshot",
      "path": "evidence/chat-self-assessment-mobile.png",
      "caption": "chat self assessment mobile",
      "condition": "viewport: 360x800"
    },
    {
      "type": "screenshot",
      "path": "evidence/entry-desktop.png",
      "caption": "entry desktop"
    },
    {
      "type": "dom",
      "path": "evidence/entry-dom.json",
      "caption": "entry dom"
    },
    {
      "type": "screenshot",
      "path": "evidence/landing-contrast.png",
      "caption": "landing contrast",
      "condition": "forced-colors: active"
    },
    {
      "type": "other",
      "path": "evidence/landing-cookies.json",
      "caption": "landing cookies"
    },
    {
      "type": "screenshot",
      "path": "evidence/landing-dark.png",
      "caption": "landing dark",
      "findingIds": [
        "F1"
      ],
      "condition": "prefers-color-scheme: dark"
    },
    {
      "type": "screenshot",
      "path": "evidence/landing-discoverability-crawler.png",
      "caption": "landing discoverability crawler"
    },
    {
      "type": "screenshot",
      "path": "evidence/landing-discoverability-rendered.png",
      "caption": "landing discoverability rendered"
    },
    {
      "type": "discoverability",
      "path": "evidence/landing-discoverability.json",
      "caption": "landing discoverability"
    },
    {
      "type": "other",
      "path": "evidence/landing-headers.json",
      "caption": "landing headers"
    },
    {
      "type": "other",
      "path": "evidence/landing-images.json",
      "caption": "landing images",
      "findingIds": [
        "F3"
      ]
    },
    {
      "type": "layout",
      "path": "evidence/landing-mobile-layout.json",
      "caption": "landing mobile layout",
      "condition": "viewport: 360x800"
    },
    {
      "type": "screenshot",
      "path": "evidence/landing-mobile.png",
      "caption": "landing mobile",
      "condition": "viewport: 360x800"
    },
    {
      "type": "other",
      "path": "evidence/landing-probe.json",
      "caption": "landing probe",
      "findingIds": [
        "F1"
      ]
    },
    {
      "type": "other",
      "path": "evidence/landing-secrets.json",
      "caption": "landing secrets"
    },
    {
      "type": "har-summary",
      "path": "evidence/landing-summary.json",
      "caption": "landing summary",
      "findingIds": [
        "F3"
      ]
    },
    {
      "type": "trace-summary",
      "path": "evidence/landing-trace-summary.json",
      "caption": "landing trace summary",
      "findingIds": [
        "F2"
      ]
    },
    {
      "type": "trace",
      "path": "evidence/landing-trace.json",
      "caption": "landing trace"
    },
    {
      "type": "other",
      "path": "evidence/landing-trackers.json",
      "caption": "landing trackers"
    },
    {
      "type": "har",
      "path": "evidence/landing.har",
      "caption": "landing"
    },
    {
      "type": "lighthouse",
      "path": "evidence/lighthouse-assistant-summary.json",
      "caption": "lighthouse assistant summary",
      "findingIds": [
        "F2",
        "F4",
        "F5"
      ]
    },
    {
      "type": "lighthouse",
      "path": "evidence/lighthouse-assistant.json",
      "caption": "lighthouse assistant"
    },
    {
      "type": "lighthouse",
      "path": "evidence/lighthouse-landing-summary.json",
      "caption": "lighthouse landing summary",
      "findingIds": [
        "F2"
      ]
    },
    {
      "type": "lighthouse",
      "path": "evidence/lighthouse-landing.json",
      "caption": "lighthouse landing"
    },
    {
      "type": "screenshot",
      "path": "evidence/login-discoverability-crawler.png",
      "caption": "login discoverability crawler"
    },
    {
      "type": "screenshot",
      "path": "evidence/login-discoverability-rendered.png",
      "caption": "login discoverability rendered"
    },
    {
      "type": "discoverability",
      "path": "evidence/login-discoverability.json",
      "caption": "login discoverability"
    },
    {
      "type": "dom",
      "path": "evidence/login-dom.json",
      "caption": "login dom"
    },
    {
      "type": "layout",
      "path": "evidence/login-layout.json",
      "caption": "login layout"
    },
    {
      "type": "screenshot",
      "path": "evidence/login-mobile.png",
      "caption": "login mobile",
      "condition": "viewport: 360x800"
    },
    {
      "type": "dom",
      "path": "evidence/not-found-dom.json",
      "caption": "not found dom"
    },
    {
      "type": "screenshot",
      "path": "evidence/not-found-mobile.png",
      "caption": "not found mobile",
      "condition": "viewport: 360x800"
    },
    {
      "type": "other",
      "path": "evidence/recon.json",
      "caption": "recon"
    },
    {
      "type": "screenshot",
      "path": "evidence/self-assessment-discoverability-crawler.png",
      "caption": "self assessment discoverability crawler"
    },
    {
      "type": "screenshot",
      "path": "evidence/self-assessment-discoverability-rendered.png",
      "caption": "self assessment discoverability rendered"
    },
    {
      "type": "discoverability",
      "path": "evidence/self-assessment-discoverability.json",
      "caption": "self assessment discoverability"
    },
    {
      "type": "dom",
      "path": "evidence/self-assessment-dom.json",
      "caption": "self assessment dom"
    },
    {
      "type": "layout",
      "path": "evidence/self-assessment-layout.json",
      "caption": "self assessment layout"
    },
    {
      "type": "screenshot",
      "path": "evidence/self-assessment-mobile.png",
      "caption": "self assessment mobile",
      "condition": "viewport: 360x800"
    }
  ],
  "config": {
    "loaded": false
  },
  "coverage": {
    "catalogVersion": "modern-web-guidance@0.0.172",
    "catalogChecksum": "sha256:78ccfdb2d483f4c57d9dafed80fd86c6265585a56457c8dcfddc254b80fb44d7",
    "expected": 58,
    "recorded": 58,
    "judged": 58,
    "blocked": 0,
    "notRun": 0,
    "missing": 0,
    "unknown": 0,
    "duplicates": 0,
    "complete": true
  },
  "checkOutcomes": [
    {
      "principleId": "respect-user-preferences",
      "checkId": "respects-color-scheme",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "The prefers-color-scheme: dark screenshot remains the same white and pale-blue light palette as the default capture; computed html color-scheme is normal.",
      "pathIds": [
        "hmrc-landing"
      ],
      "artifacts": [
        "evidence/landing-dark.png",
        "evidence/landing-probe.json"
      ],
      "findingIds": [
        "F1"
      ]
    },
    {
      "principleId": "respect-user-preferences",
      "checkId": "respects-reduced-motion",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Reduced-motion probe reported zero active animations.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-probe.json",
        "evidence/assistant-probe.json"
      ]
    },
    {
      "principleId": "respect-user-preferences",
      "checkId": "respects-contrast",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Forced-colors capture retains legible text, links, button boundaries and focus affordances.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-contrast.png"
      ]
    },
    {
      "principleId": "implement-natural-interactions",
      "checkId": "view-transitions",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "No active animations appeared under reduced motion; CSS exposes a root view-transition name and the sampled pages use ordinary native scrolling/navigation without custom pointer handlers.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "implement-natural-interactions",
      "checkId": "scroll-driven-animations",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No scroll-linked animation is present on the representative pages.",
      "reason": "No scroll-linked animation is present on the representative pages."
    },
    {
      "principleId": "implement-natural-interactions",
      "checkId": "physical-gestures",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No gesture-driven control is present in the representative journeys.",
      "reason": "No gesture-driven control is present in the representative journeys."
    },
    {
      "principleId": "provide-guided-navigation",
      "checkId": "scroll-state-aware-chrome",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Breadcrumbs, contents links, descriptive route labels, back/skip links and focused chat state guide location and attention across the tested journey.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "provide-guided-navigation",
      "checkId": "anchored-positioning",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No tooltip, popover, or floating menu requiring anchored positioning appears in the tested paths.",
      "reason": "No tooltip, popover, or floating menu requiring anchored positioning appears in the tested paths."
    },
    {
      "principleId": "provide-guided-navigation",
      "checkId": "directs-attention",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Breadcrumbs, contents links, descriptive route labels, back/skip links and focused chat state guide location and attention across the tested journey.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "maximize-content-reduce-noise",
      "checkId": "no-intrusive-interruptions",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Screenshots show content-first GOV.UK layouts; cookie choices are visible, equally weighted and dismissible rather than modal, and no load-time overlay obscures the document.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png"
      ]
    },
    {
      "principleId": "maximize-content-reduce-noise",
      "checkId": "semantic-dismissible-primitives",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No modal, popover, custom select, or disclosure is used in the tested core path; the cookie choice is an in-flow semantic region.",
      "reason": "No modal, popover, custom select, or disclosure is used in the tested core path; the cookie choice is an in-flow semantic region."
    },
    {
      "principleId": "maximize-content-reduce-noise",
      "checkId": "reduced-chrome",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Screenshots show content-first GOV.UK layouts; cookie choices are visible, equally weighted and dismissible rather than modal, and no load-time overlay obscures the document.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png"
      ]
    },
    {
      "principleId": "adapt-to-the-form-factor",
      "checkId": "responsive-no-horizontal-scroll",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "All four mobile layouts reported 360px scrollWidth for a 360px viewport with zero overflow; GOV.UK focus styling and @container rules were observed.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/landing-mobile-layout.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "adapt-to-the-form-factor",
      "checkId": "component-level-responsiveness",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "All four mobile layouts reported 360px scrollWidth for a 360px viewport with zero overflow; GOV.UK focus styling and @container rules were observed.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/landing-mobile-layout.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "adapt-to-the-form-factor",
      "checkId": "input-modality-aware",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "All four mobile layouts reported 360px scrollWidth for a 360px viewport with zero overflow; GOV.UK focus styling and @container rules were observed.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/landing-mobile-layout.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "support-core-task-success",
      "checkId": "clear-purpose-and-primary-action",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "The landing states HMRC’s purpose, links directly to sign-in and tax tasks, and the tested Ask HMRC > Self Assessment journey reached a labelled chat input, status message, Send and End chat controls.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json",
        "evidence/not-found-mobile.png"
      ]
    },
    {
      "principleId": "support-core-task-success",
      "checkId": "primary-flow-completion",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "The landing states HMRC’s purpose, links directly to sign-in and tax tasks, and the tested Ask HMRC > Self Assessment journey reached a labelled chat input, status message, Send and End chat controls.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json",
        "evidence/not-found-mobile.png"
      ]
    },
    {
      "principleId": "support-core-task-success",
      "checkId": "clear-system-state-and-recovery",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "The landing states HMRC’s purpose, links directly to sign-in and tax tasks, and the tested Ask HMRC > Self Assessment journey reached a labelled chat input, status message, Send and End chat controls.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json",
        "evidence/not-found-mobile.png"
      ]
    },
    {
      "principleId": "be-fast-and-stable",
      "checkId": "good-core-web-vitals",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "Lighthouse measured landing LCP 4.22s and CLS 0.556; the assistant measured LCP 5.07s. The trace corroborated a responsive main thread (0ms TBT), so loading and layout stability are the main concerns.",
      "pathIds": [
        "hmrc-landing"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/landing-trace-summary.json"
      ],
      "findingIds": [
        "F2"
      ]
    },
    {
      "principleId": "be-fast-and-stable",
      "checkId": "visual-stability",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Trace, HAR, layout and Lighthouse evidence directly measured loading, stability, main-thread and delivery behaviour across the landing and assistant routes.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-trace-summary.json",
        "evidence/landing-summary.json",
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json"
      ]
    },
    {
      "principleId": "be-fast-and-stable",
      "checkId": "efficient-main-thread",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Trace, HAR, layout and Lighthouse evidence directly measured loading, stability, main-thread and delivery behaviour across the landing and assistant routes.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-trace-summary.json",
        "evidence/landing-summary.json",
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json"
      ]
    },
    {
      "principleId": "be-fast-and-stable",
      "checkId": "efficient-resource-delivery",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Trace, HAR, layout and Lighthouse evidence directly measured loading, stability, main-thread and delivery behaviour across the landing and assistant routes.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-trace-summary.json",
        "evidence/landing-summary.json",
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json"
      ]
    },
    {
      "principleId": "be-fast-and-stable",
      "checkId": "trim-unused-and-duplicate-code",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "Its HAR transfers 583KB of script. Lighthouse estimated 235KiB unused JavaScript, 81KiB unminified JavaScript and 35KiB unused CSS.",
      "pathIds": [
        "assistant-selector"
      ],
      "artifacts": [
        "evidence/lighthouse-assistant-summary.json",
        "evidence/assistant-summary.json"
      ],
      "findingIds": [
        "F4"
      ]
    },
    {
      "principleId": "be-inclusive",
      "checkId": "names-roles-labels",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse accessibility scored 1.00 on both the organisation and assistant routes; mobile screenshots and the chat DOM corroborate labelled controls, landmarks, live messaging and readable reflow.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-inclusive",
      "checkId": "sufficient-contrast",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse accessibility scored 1.00 on both the organisation and assistant routes; mobile screenshots and the chat DOM corroborate labelled controls, landmarks, live messaging and readable reflow.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-inclusive",
      "checkId": "structure-and-focus",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse accessibility scored 1.00 on both the organisation and assistant routes; mobile screenshots and the chat DOM corroborate labelled controls, landmarks, live messaging and readable reflow.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-inclusive",
      "checkId": "legible-text",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse accessibility scored 1.00 on both the organisation and assistant routes; mobile screenshots and the chat DOM corroborate labelled controls, landmarks, live messaging and readable reflow.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-inclusive",
      "checkId": "zoom-reflow-targets-and-media",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse accessibility scored 1.00 on both the organisation and assistant routes; mobile screenshots and the chat DOM corroborate labelled controls, landmarks, live messaging and readable reflow.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "follow-best-practices",
      "checkId": "no-console-errors",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse, DOM and evaluate evidence confirms valid HTML/UTF-8, viewport, sized images and no landing-page console/best-practice failure; assistant platform exceptions are recorded.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/landing-probe.json",
        "evidence/landing-images.json"
      ]
    },
    {
      "principleId": "follow-best-practices",
      "checkId": "sound-document-and-assets",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Lighthouse, DOM and evaluate evidence confirms valid HTML/UTF-8, viewport, sized images and no landing-page console/best-practice failure; assistant platform exceptions are recorded.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/landing-probe.json",
        "evidence/landing-images.json"
      ]
    },
    {
      "principleId": "follow-best-practices",
      "checkId": "browser-platform-hygiene",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "Lighthouse reported one deprecated API, DevTools Issues panel entries, two BFCache failure reasons, and a best-practices score of 0.58.",
      "pathIds": [
        "assistant-selector"
      ],
      "artifacts": [
        "evidence/lighthouse-assistant-summary.json"
      ],
      "findingIds": [
        "F5"
      ]
    },
    {
      "principleId": "be-discoverable",
      "checkId": "title-and-description",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw-HTML comparison found 100% content coverage on the public landing, sign-in guide and Self Assessment guide, with title, h1 and descriptions in raw HTML; canonical/JSON-LD/Open Graph and real hrefs were present.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "be-discoverable",
      "checkId": "crawlable-and-mobile-friendly",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw-HTML comparison found 100% content coverage on the public landing, sign-in guide and Self Assessment guide, with title, h1 and descriptions in raw HTML; canonical/JSON-LD/Open Graph and real hrefs were present.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "be-discoverable",
      "checkId": "canonical-and-indexing-signals",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw-HTML comparison found 100% content coverage on the public landing, sign-in guide and Self Assessment guide, with title, h1 and descriptions in raw HTML; canonical/JSON-LD/Open Graph and real hrefs were present.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "be-discoverable",
      "checkId": "structured-and-shareable-metadata",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw-HTML comparison found 100% content coverage on the public landing, sign-in guide and Self Assessment guide, with title, h1 and descriptions in raw HTML; canonical/JSON-LD/Open Graph and real hrefs were present.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/landing-probe.json"
      ]
    },
    {
      "principleId": "be-private-and-secure",
      "checkId": "secure-transport-and-headers",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "The cookie primitive found optimizelyOptOut scoped to .tax.service.gov.uk, Secure=false, SameSite=None and a 400-day expiry. HSTS mitigates many downgrade paths but does not justify an insecure cookie attribute.",
      "pathIds": [
        "assistant-selector"
      ],
      "artifacts": [
        "evidence/assistant-cookies.json"
      ],
      "findingIds": [
        "F6"
      ]
    },
    {
      "principleId": "be-private-and-secure",
      "checkId": "data-minimisation-and-third-parties",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "HTTPS, nonce CSP, HSTS, nosniff and frame protection were observed; no exposed secrets or known tracker origins were found. The assistant-specific gaps are separately recorded.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-headers.json",
        "evidence/assistant-headers.json",
        "evidence/assistant-cookies.json"
      ]
    },
    {
      "principleId": "be-private-and-secure",
      "checkId": "in-context-permissions-and-modern-auth",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "HTTPS, nonce CSP, HSTS, nosniff and frame protection were observed; no exposed secrets or known tracker origins were found. The assistant-specific gaps are separately recorded.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-headers.json",
        "evidence/assistant-headers.json",
        "evidence/assistant-cookies.json"
      ]
    },
    {
      "principleId": "be-private-and-secure",
      "checkId": "defensive-browser-policies",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "Headers evidence shows a CSP containing unsafe-inline and no Permissions-Policy on the assistant, while HSTS, nosniff and clickjacking protection are present.",
      "pathIds": [
        "assistant-selector"
      ],
      "artifacts": [
        "evidence/assistant-headers.json"
      ],
      "findingIds": [
        "F7"
      ]
    },
    {
      "principleId": "be-resilient",
      "checkId": "progressive-enhancement",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw HTML preserved core public content; the tested 404 gives a clear “Page not found” state with recovery links, and the assistant selector/chat loaded without a JS shell.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/not-found-mobile.png",
        "evidence/chat-self-assessment-mobile.png"
      ]
    },
    {
      "principleId": "be-resilient",
      "checkId": "resilient-runtime-behaviour",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw HTML preserved core public content; the tested 404 gives a clear “Page not found” state with recovery links, and the assistant selector/chat loaded without a JS shell.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/not-found-mobile.png",
        "evidence/chat-self-assessment-mobile.png"
      ]
    },
    {
      "principleId": "be-resilient",
      "checkId": "offline-and-installable",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "The public content is informational and the tax/chat task intrinsically requires a live government service; installability is not an expected core outcome.",
      "reason": "The public content is informational and the tax/chat task intrinsically requires a live government service; installability is not an expected core outcome."
    },
    {
      "principleId": "be-resilient",
      "checkId": "network-and-http-failure-states",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Raw HTML preserved core public content; the tested 404 gives a clear “Page not found” state with recovery links, and the assistant selector/chat loaded without a JS shell.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-discoverability.json",
        "evidence/not-found-mobile.png",
        "evidence/chat-self-assessment-mobile.png"
      ]
    },
    {
      "principleId": "be-internationalised",
      "checkId": "lang-dir-and-logical-properties",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "HTML lang=en is correct and visible Welsh alternatives are offered; mobile reflow remains intact.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-probe.json",
        "evidence/landing-mobile.png"
      ]
    },
    {
      "principleId": "be-internationalised",
      "checkId": "locale-aware-data",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "The sampled pages do not render locale-sensitive dates, numbers, currencies, durations, or calendar data.",
      "reason": "The sampled pages do not render locale-sensitive dates, numbers, currencies, durations, or calendar data."
    },
    {
      "principleId": "be-internationalised",
      "checkId": "time-zone-correctness",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "The sampled pages contain no event or time-zone workflow.",
      "reason": "The sampled pages contain no event or time-zone workflow."
    },
    {
      "principleId": "be-trustworthy",
      "checkId": "no-dark-patterns",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Cookie choices give equally prominent accept/reject controls; the chat warns against personal data, exposes End chat, labels input, and provides live-region announcements.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-trustworthy",
      "checkId": "humane-error-handling",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Cookie choices give equally prominent accept/reject controls; the chat warns against personal data, exposes End chat, labels input, and provides live-region announcements.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-trustworthy",
      "checkId": "trustworthy-input-assistance",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Cookie choices give equally prominent accept/reject controls; the chat warns against personal data, exposes End chat, labels input, and provides live-region announcements.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-mobile.png",
        "evidence/chat-self-assessment-mobile.png",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-trustworthy",
      "checkId": "safe-commercial-and-account-flows",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No checkout, subscription, payment, cancellation, or sensitive account mutation was in the unauthenticated representative scope.",
      "reason": "No checkout, subscription, payment, cancellation, or sensitive account mutation was in the unauthenticated representative scope."
    },
    {
      "principleId": "be-sustainable",
      "checkId": "optimised-assets",
      "status": "issues",
      "confidence": "high",
      "method": "Cross-path visual and objective evidence review against the mapped Modern Web Guidance.",
      "evidence": "HAR measured 2.08MB of images out of 2.25MB total. The images primitive found 21/21 legacy-format images, no srcset, all below-fold images eager, and all natural dimensions over twice display width.",
      "pathIds": [
        "hmrc-landing"
      ],
      "artifacts": [
        "evidence/landing-summary.json",
        "evidence/landing-images.json"
      ],
      "findingIds": [
        "F3"
      ]
    },
    {
      "principleId": "be-sustainable",
      "checkId": "no-wasteful-work",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "HAR, image and Lighthouse evidence measured page weight, third-party origins and background/main-thread work; issue rows capture the observed image waste.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-summary.json",
        "evidence/landing-images.json",
        "evidence/landing-trace-summary.json"
      ]
    },
    {
      "principleId": "be-sustainable",
      "checkId": "third-party-and-media-budget",
      "status": "pass",
      "confidence": "high",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "HAR, image and Lighthouse evidence measured page weight, third-party origins and background/main-thread work; issue rows capture the observed image waste.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/landing-summary.json",
        "evidence/landing-images.json",
        "evidence/landing-trace-summary.json"
      ]
    },
    {
      "principleId": "be-agent-ready",
      "checkId": "structured-agent-capabilities",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No declared agent-facing capability is expected for this public information and support journey; this emerging check is contextual.",
      "reason": "No declared agent-facing capability is expected for this public information and support journey; this emerging check is contextual."
    },
    {
      "principleId": "be-agent-ready",
      "checkId": "on-device-inference",
      "status": "not-applicable",
      "confidence": "high",
      "method": "Applicability judgement from representative-route recon.",
      "evidence": "No user task here calls for on-device inference; this emerging capability is contextual.",
      "reason": "No user task here calls for on-device inference; this emerging capability is contextual."
    },
    {
      "principleId": "be-memory-efficient",
      "checkId": "no-leak-under-repeated-interaction",
      "status": "pass",
      "confidence": "medium",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Chat heap snapshots were about 14.9MB baseline and 15.3MB after ten empty-send attempts; the bounded one-page footprint and constructor summaries showed no evidence of unbounded or detached-DOM growth in this short run.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/chat-heap-baseline.json",
        "evidence/chat-heap-post.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-memory-efficient",
      "checkId": "bounded-footprint",
      "status": "pass",
      "confidence": "medium",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Chat heap snapshots were about 14.9MB baseline and 15.3MB after ten empty-send attempts; the bounded one-page footprint and constructor summaries showed no evidence of unbounded or detached-DOM growth in this short run.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/chat-heap-baseline.json",
        "evidence/chat-heap-post.json",
        "evidence/chat-probe.json"
      ]
    },
    {
      "principleId": "be-memory-efficient",
      "checkId": "no-detached-dom-or-unbounded-listeners",
      "status": "pass",
      "confidence": "medium",
      "method": "Cross-path DOM, screenshot, Lighthouse and/or purpose-specific primitive review.",
      "evidence": "Chat heap snapshots were about 14.9MB baseline and 15.3MB after ten empty-send attempts; the bounded one-page footprint and constructor summaries showed no evidence of unbounded or detached-DOM growth in this short run.",
      "pathIds": [
        "hmrc-landing",
        "sign-in-guide",
        "self-assessment-guide",
        "assistant-selector",
        "assistant-chat",
        "error-recovery"
      ],
      "artifacts": [
        "evidence/chat-heap-baseline.json",
        "evidence/chat-heap-post.json",
        "evidence/chat-probe.json"
      ]
    }
  ],
  "principleOutcomes": [
    {
      "principleId": "respect-user-preferences",
      "expectation": "default",
      "status": "issues",
      "findingIds": [
        "F1"
      ]
    },
    {
      "principleId": "implement-natural-interactions",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "provide-guided-navigation",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "maximize-content-reduce-noise",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "adapt-to-the-form-factor",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "support-core-task-success",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "be-fast-and-stable",
      "expectation": "default",
      "status": "issues",
      "findingIds": [
        "F2",
        "F4"
      ]
    },
    {
      "principleId": "be-inclusive",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "follow-best-practices",
      "expectation": "default",
      "status": "issues",
      "findingIds": [
        "F5"
      ]
    },
    {
      "principleId": "be-discoverable",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "be-private-and-secure",
      "expectation": "default",
      "status": "issues",
      "findingIds": [
        "F6",
        "F7"
      ]
    },
    {
      "principleId": "be-resilient",
      "expectation": "contextual",
      "status": "pass"
    },
    {
      "principleId": "be-internationalised",
      "expectation": "contextual",
      "status": "pass"
    },
    {
      "principleId": "be-trustworthy",
      "expectation": "default",
      "status": "pass"
    },
    {
      "principleId": "be-sustainable",
      "expectation": "contextual",
      "status": "issues",
      "findingIds": [
        "F3"
      ]
    },
    {
      "principleId": "be-agent-ready",
      "expectation": "contextual",
      "status": "not-applicable",
      "reason": "All checks were judged contextual and outside this site’s intended public-information/support scope."
    },
    {
      "principleId": "be-memory-efficient",
      "expectation": "default",
      "status": "pass"
    }
  ],
  "paths": [
    {
      "id": "hmrc-landing",
      "description": "Redirect destination and organisation/index archetype; establishes public purpose, navigation, content density and global policy.",
      "url": "https://www.gov.uk/government/organisations/hm-revenue-customs",
      "conditions": [
        "desktop",
        "viewport: 360x800",
        "prefers-color-scheme: dark",
        "prefers-reduced-motion: reduce",
        "forced-colors: active"
      ],
      "result": "issues"
    },
    {
      "id": "sign-in-guide",
      "description": "Primary account-entry guidance archetype, representing the unauthenticated sign-in journey.",
      "url": "https://www.gov.uk/log-in-register-hmrc-online-services",
      "conditions": [
        "viewport: 360x800",
        "no JavaScript crawler"
      ],
      "result": "pass"
    },
    {
      "id": "self-assessment-guide",
      "description": "High-value tax guidance/content archetype and route into a core tax task.",
      "url": "https://www.gov.uk/self-assessment-tax-returns",
      "conditions": [
        "viewport: 360x800",
        "no JavaScript crawler"
      ],
      "result": "pass"
    },
    {
      "id": "assistant-selector",
      "description": "Interactive HMRC service selector on the requested host, representing service-specific frontend policy and delivery.",
      "url": "https://www.tax.service.gov.uk/ask-hmrc/hmrc-digital-assistant",
      "conditions": [
        "viewport: 360x800",
        "prefers-reduced-motion: reduce",
        "no JavaScript crawler"
      ],
      "result": "issues"
    },
    {
      "id": "assistant-chat",
      "description": "Primary unauthenticated support flow: select Self Assessment and reach the live chat input and recovery controls.",
      "url": "https://www.tax.service.gov.uk/ask-hmrc/chat/self-assessment",
      "conditions": [
        "viewport: 360x800",
        "empty submission",
        "10 repeated empty-send attempts"
      ],
      "result": "pass"
    },
    {
      "id": "error-recovery",
      "description": "Representative invalid GOV.UK route to test network/HTTP failure communication and recovery.",
      "url": "https://www.gov.uk/this-route-does-not-exist-web-uplift",
      "conditions": [
        "viewport: 360x800"
      ],
      "result": "pass"
    }
  ],
  "findings": [
    {
      "id": "F1",
      "severity": "medium",
      "confidence": "high",
      "pathId": "hmrc-landing",
      "url": "https://www.gov.uk/government/organisations/hm-revenue-customs",
      "principleId": "respect-user-preferences",
      "principleCheckId": "respects-color-scheme",
      "guidanceId": "dark-mode",
      "guidanceCategory": "user-experience",
      "summary": "The service does not adapt its colour scheme to the user’s dark-mode preference.",
      "evidence": "The prefers-color-scheme: dark screenshot remains the same white and pale-blue light palette as the default capture; computed html color-scheme is normal.",
      "artifacts": [
        "evidence/landing-dark.png",
        "evidence/landing-probe.json"
      ],
      "suggestedFix": "Declare color-scheme and provide preference-driven dark surface, text, link, focus and form-control colours, following the dark-mode guidance.",
      "effort": "medium"
    },
    {
      "id": "F2",
      "severity": "high",
      "confidence": "high",
      "pathId": "hmrc-landing",
      "url": "https://www.gov.uk/government/organisations/hm-revenue-customs",
      "principleId": "be-fast-and-stable",
      "principleCheckId": "good-core-web-vitals",
      "guidanceId": "performance",
      "guidanceCategory": "performance",
      "summary": "Key pages miss the good LCP bar, and the organisation landing page has severe lab layout shift.",
      "evidence": "Lighthouse measured landing LCP 4.22s and CLS 0.556; the assistant measured LCP 5.07s. The trace corroborated a responsive main thread (0ms TBT), so loading and layout stability are the main concerns.",
      "artifacts": [
        "evidence/lighthouse-landing-summary.json",
        "evidence/lighthouse-assistant-summary.json",
        "evidence/landing-trace-summary.json"
      ],
      "suggestedFix": "Use the Lighthouse shift culprits and LCP dependency chain to reserve late content space and prioritize the actual LCP resource; remeasure under mobile throttling.",
      "effort": "medium"
    },
    {
      "id": "F3",
      "severity": "medium",
      "confidence": "high",
      "pathId": "hmrc-landing",
      "url": "https://www.gov.uk/government/organisations/hm-revenue-customs",
      "principleId": "be-sustainable",
      "principleCheckId": "optimised-assets",
      "guidanceId": "optimize-image-priority",
      "guidanceCategory": "performance",
      "summary": "The image-heavy organisation page transfers disproportionate legacy, non-responsive imagery.",
      "evidence": "HAR measured 2.08MB of images out of 2.25MB total. The images primitive found 21/21 legacy-format images, no srcset, all below-fold images eager, and all natural dimensions over twice display width.",
      "artifacts": [
        "evidence/landing-summary.json",
        "evidence/landing-images.json"
      ],
      "suggestedFix": "Generate AVIF/WebP responsive variants, add srcset/sizes, lazy-load below-fold images, and keep eager/high-priority loading only for the true LCP image.",
      "effort": "medium"
    },
    {
      "id": "F4",
      "severity": "medium",
      "confidence": "high",
      "pathId": "assistant-selector",
      "url": "https://www.tax.service.gov.uk/ask-hmrc/hmrc-digital-assistant",
      "principleId": "be-fast-and-stable",
      "principleCheckId": "trim-unused-and-duplicate-code",
      "guidanceId": "identify-heavy-scripts",
      "guidanceCategory": "performance",
      "summary": "The assistant selector ships avoidable JavaScript and CSS.",
      "evidence": "Its HAR transfers 583KB of script. Lighthouse estimated 235KiB unused JavaScript, 81KiB unminified JavaScript and 35KiB unused CSS.",
      "artifacts": [
        "evidence/lighthouse-assistant-summary.json",
        "evidence/assistant-summary.json"
      ],
      "suggestedFix": "Remove unused bundles on the selector route, minify production scripts, and conditionally load the chat client only after a topic is chosen.",
      "effort": "medium"
    },
    {
      "id": "F5",
      "severity": "medium",
      "confidence": "high",
      "pathId": "assistant-selector",
      "url": "https://www.tax.service.gov.uk/ask-hmrc/hmrc-digital-assistant",
      "principleId": "follow-best-practices",
      "principleCheckId": "browser-platform-hygiene",
      "guidanceId": "html",
      "guidanceCategory": "html",
      "summary": "The assistant route triggers browser-platform hygiene failures.",
      "evidence": "Lighthouse reported one deprecated API, DevTools Issues panel entries, two BFCache failure reasons, and a best-practices score of 0.58.",
      "artifacts": [
        "evidence/lighthouse-assistant-summary.json"
      ],
      "suggestedFix": "Inspect the named deprecated call and BFCache blockers in DevTools, replace the deprecated API, and remove unload/cache blockers so history navigation can restore the page.",
      "effort": "small"
    },
    {
      "id": "F6",
      "severity": "medium",
      "confidence": "high",
      "pathId": "assistant-selector",
      "url": "https://www.tax.service.gov.uk/ask-hmrc/hmrc-digital-assistant",
      "principleId": "be-private-and-secure",
      "principleCheckId": "secure-transport-and-headers",
      "guidanceId": "security",
      "guidanceCategory": "security",
      "summary": "The assistant sets a long-lived cookie without the Secure flag.",
      "evidence": "The cookie primitive found optimizelyOptOut scoped to .tax.service.gov.uk, Secure=false, SameSite=None and a 400-day expiry. HSTS mitigates many downgrade paths but does not justify an insecure cookie attribute.",
      "artifacts": [
        "evidence/assistant-cookies.json"
      ],
      "suggestedFix": "Set Secure and an appropriate SameSite value on every cookie; reduce the preference cookie lifetime unless a documented need requires 400 days.",
      "effort": "trivial"
    },
    {
      "id": "F7",
      "severity": "medium",
      "confidence": "high",
      "pathId": "assistant-selector",
      "url": "https://www.tax.service.gov.uk/ask-hmrc/hmrc-digital-assistant",
      "principleId": "be-private-and-secure",
      "principleCheckId": "defensive-browser-policies",
      "guidanceId": "security",
      "guidanceCategory": "security",
      "summary": "The assistant’s browser-enforced policy set is weaker than the GOV.UK landing page’s.",
      "evidence": "Headers evidence shows a CSP containing unsafe-inline and no Permissions-Policy on the assistant, while HSTS, nosniff and clickjacking protection are present.",
      "artifacts": [
        "evidence/assistant-headers.json"
      ],
      "suggestedFix": "Remove unsafe-inline once nonce-based execution is complete and add a least-privilege Permissions-Policy for capabilities the service does not use.",
      "effort": "small"
    }
  ],
  "taskList": [
    {
      "id": "T1",
      "title": "Fix LCP and landing-page layout shift",
      "priority": 1,
      "findingIds": [
        "F2"
      ],
      "guidanceId": "performance",
      "status": "open"
    },
    {
      "id": "T2",
      "title": "Serve responsive modern images and lazy-load below-fold media",
      "priority": 2,
      "findingIds": [
        "F3"
      ],
      "guidanceId": "optimize-image-priority",
      "status": "open"
    },
    {
      "id": "T3",
      "title": "Harden assistant cookies and browser policies",
      "priority": 3,
      "findingIds": [
        "F6",
        "F7"
      ],
      "guidanceId": "security",
      "status": "open"
    },
    {
      "id": "T4",
      "title": "Trim and conditionally load assistant JavaScript",
      "priority": 4,
      "findingIds": [
        "F4"
      ],
      "guidanceId": "identify-heavy-scripts",
      "status": "open"
    },
    {
      "id": "T5",
      "title": "Remove deprecated API and BFCache blockers",
      "priority": 5,
      "findingIds": [
        "F5"
      ],
      "guidanceId": "html",
      "status": "open"
    },
    {
      "id": "T6",
      "title": "Add user-preference-driven dark mode",
      "priority": 6,
      "findingIds": [
        "F1"
      ],
      "guidanceId": "dark-mode",
      "status": "open"
    }
  ],
  "budget": {
    "pathCount": 6,
    "auditPasses": 1
  },
  "agent": "pi",
  "runId": "2026-07-22T11-42-31-501Z"
}