{
  "id": "grok-4-fast",
  "language": "zh-Hant",
  "url": "https://alexgetman.com/zh-Hant/models/xai/grok-4-fast/",
  "name": "Grok 4 Fast",
  "model_identity": {
    "id": "grok-4-fast",
    "name": "Grok 4 Fast",
    "maker": {
      "id": "xai",
      "name": "xAI"
    },
    "version": null,
    "checkpoint": null,
    "first_seen_at": "2026-11-05T17:47:58.156Z"
  },
  "catalogue_section": "main",
  "stage": "released",
  "expectation": {
    "state": "released",
    "last_evidence_at": "2026-11-05T17:47:58.156Z",
    "related_model_id": null,
    "evidence": [],
    "claims": [
      {
        "reference": "code:github:xai-org/grok-build:models:grok-4-fast:Test:f9ca4f76e5e03a5efe5a073e3d8620c8d627321bb91d83446249b742925b802f",
        "outcome": "unresolved"
      },
      {
        "reference": "record:xai-articles:https://x.ai/news/grok-4-fast:grok-4-fast",
        "outcome": "unresolved"
      }
    ]
  },
  "watch_presentation": {
    "placement": "expected",
    "family": {
      "key": "xai:grok-fast",
      "name": "Grok Fast"
    }
  },
  "observations": [],
  "timeline": [
    {
      "reference": "code:github:xai-org/grok-build:models:grok-4-fast:Test:f9ca4f76e5e03a5efe5a073e3d8620c8d627321bb91d83446249b742925b802f",
      "kind": "catalogue_listed",
      "at": "2026-11-05T17:47:58.156Z",
      "historical": false,
      "code_usage": "test",
      "source": "github:xai-org/grok-build:models",
      "source_label": "GitHub · xai-org/grok-build · code",
      "url": "https://github.com/xai-org/grok-build/blob/2bdd1d6a6369de0e8c68132ea4539e9abd9e14a8/crates/codegen/xai-grok-pager/src/headless/reducer/messages/tests/content.rs",
      "quote": "response_started(\"msg_a\", Some(\"grok-4\"), 5)));\n    out.extend(r.reduce(StreamEvent::AgentMessage(\"from A\".into())));\n    out.extend(r.reduce(response_completed(\"msg_a\", \"end_turn\")));\n    out.extend(r.reduce(response_started(\"msg_b\", Some(\"grok-4-fast\"), 6)));\n    out.extend(r.reduce(StreamEvent::AgentMessage(\"from B\".into())));\n    out.extend(r.reduce(response_completed(\"msg_b\", \"end_turn\")));\n    out.extend(r.finish(&end_turn()));\n    let frames: Vec<&Value> = out\n        .iter()\n        .filter(|m| msg_type(m) == Some(\"assistant\"))\n        .collect();\n    let [a, b] = frames.as_slice() else {\n        panic!(\"one frame per response: {out:?}\");\n    };\n    assert_eq!(json_str(a, \"/message/id\"), Some(\"msg_a\"));\n    assert_eq!(json_str(a, \"/message/model\"), Some(\"grok-4\"));\n    assert_eq!(json_str(b, \"/message/id\"), Some(\"msg_b\"));\n    assert_eq!(json_str(b, \"/message/model\"), Som",
      "co_mentions": []
    },
    {
      "reference": "record:xai-articles:https://x.ai/news/grok-4-fast:grok-4-fast",
      "kind": "editorial_mention",
      "at": "2026-11-13T18:39:46.933Z",
      "event_at": {
        "precision": "day",
        "value": "2025-09-19"
      },
      "historical": true,
      "watch_focus": "unknown",
      "source": "xai-articles",
      "source_label": "xAI · official articles",
      "url": "https://x.ai/news/grok-4-fast",
      "quote": "Grok 4 Fast is available now for all users",
      "co_mentions": []
    }
  ],
  "offers": [],
  "dates": [
    {
      "kind": "model_release",
      "scope": {
        "kind": "model",
        "id": "grok-4-fast"
      },
      "at": {
        "precision": "day",
        "value": "2025-09-19"
      },
      "release_scope": "official_documented_access",
      "selected": true,
      "evidence": [
        {
          "source": "xai-articles",
          "url": "https://x.ai/news/grok-4-fast",
          "authority": "primary",
          "scope": {
            "kind": "model",
            "id": "grok-4-fast"
          },
          "detected_at": "2026-11-13T18:39:46.933Z",
          "checked_at": "2026-11-14T18:32:55.313Z"
        }
      ]
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      "kind": "model_release",
      "scope": {
        "kind": "model",
        "id": "grok-4-fast"
      },
      "at": {
        "precision": "day",
        "value": "2025-09-20"
      },
      "release_scope": null,
      "selected": false,
      "evidence": [
        {
          "source": "models-dev",
          "url": null,
          "authority": "third_party",
          "scope": {
            "kind": "model",
            "id": "grok-4-fast"
          },
          "detected_at": null,
          "checked_at": "2026-11-12T16:13:02.548Z"
        }
      ]
    },
    {
      "kind": "model_release",
      "scope": {
        "kind": "model",
        "id": "grok-4-fast"
      },
      "at": {
        "precision": "day",
        "value": "2025-09-19"
      },
      "release_scope": "official_documented_access",
      "selected": true,
      "evidence": [
        {
          "source": "xai-articles",
          "url": "https://x.ai/news/grok-4-fast",
          "authority": "primary",
          "scope": {
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            "id": "grok-4-fast"
          },
          "detected_at": "2026-11-13T18:39:46.933Z",
          "checked_at": "2026-11-14T16:30:43.794Z"
        }
      ]
    }
  ],
  "vendor": "xAI",
  "summary": "Grok 4 Fast 是 xAI 的 AI 模型，於 2025-09-19 發布。",
  "editorial_guide": null,
  "first_seen_at": "2026-11-05T17:47:58.156Z",
  "first_reported_at": "2025-09-19T00:00:00.000Z",
  "detection": {
    "at": "2026-09-19T17:20:46.653Z",
    "kind": "catalogue_listing",
    "evidence": [
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        "url": "https://models.dev/#grok-4-fast",
        "authority": "third_party",
        "scope": {
          "kind": "model",
          "id": "grok-4-fast"
        },
        "detected_at": "2026-09-19T17:20:46.653Z",
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      }
    ]
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  "days_early": null,
  "released_at": "2025-09-19T00:00:00.000Z",
  "updated_at": "2026-11-14T18:34:16.695Z",
  "forge_facts": [
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      "key": "makerStatus",
      "value": {
        "status": "access_established",
        "source_event": {
          "precision": "day",
          "value": "2025-09-19"
        },
        "basis": "explicit_maker_statement",
        "statements": [
          {
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            "evidence": {
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            }
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        ]
      },
      "observed_at": null
    },
    {
      "key": "watchFocus",
      "value": {
        "category": "unknown",
        "home_eligible": false,
        "basis": "maker_lifecycle"
      },
      "observed_at": null
    }
  ],
  "provenance": {
    "makerStatus": [
      {
        "source": "xai-articles",
        "url": "https://x.ai/news/grok-4-fast",
        "authority": "primary",
        "scope": {
          "kind": "model",
          "id": "grok-4-fast"
        },
        "detected_at": "2026-11-13T18:39:46.933Z",
        "checked_at": "2026-11-14T18:32:55.313Z"
      }
    ],
    "watchFocus": [
      {
        "source": "xai-articles",
        "url": "https://x.ai/news/grok-4-fast",
        "authority": "primary",
        "scope": {
          "kind": "model",
          "id": "grok-4-fast"
        },
        "detected_at": "2026-11-13T18:39:46.933Z",
        "checked_at": null
      }
    ]
  },
  "sources": [
    {
      "url": "https://artificialanalysis.ai/models",
      "source": "Artificial Analysis · benchmarks"
    },
    {
      "url": "https://github.com/xai-org/grok-build/blob/2bdd1d6a6369de0e8c68132ea4539e9abd9e14a8/crates/codegen/xai-grok-pager/src/headless/reducer/messages/tests/content.rs",
      "source": "GitHub · xai-org/grok-build · code"
    },
    {
      "url": "https://models.dev/#grok-4-fast",
      "source": "models-dev"
    },
    {
      "url": "https://models.dev/#grok-4-fast-non-reasoning",
      "source": "models.dev · catalogue"
    },
    {
      "url": "https://opencode.ai/data/xai/grok-4-fast-non-reasoning",
      "source": "OpenCode · discovery"
    },
    {
      "url": "https://x.ai/news/grok-4-fast",
      "source": "xai-articles"
    }
  ],
  "facts": {
    "context_window": null,
    "max_output_tokens": null,
    "input_modalities": [],
    "output_modalities": [],
    "open_weights": null,
    "usd_per_million": {
      "input": null,
      "output": null,
      "cached_input": null
    },
    "prices": {
      "currency": "USD",
      "unit": "per_million_tokens",
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      "cached_input": null
    },
    "observed_at": null,
    "output_kind": "unknown",
    "provenance": {}
  },
  "signals": [
    {
      "title": "在 models.dev 發現 Grok 4 Fast",
      "url": "https://alexgetman.com/zh-Hant/signals/2026/09/19/grok-4-fast/"
    }
  ]
}