{
  "$schema": "https://degreesofsatoshi.com/encyclopedia/schemas/article-v1.json",
  "schemaVersion": "1.0.0",
  "id": "arbitrum-one",
  "canonical": "https://degreesofsatoshi.com/encyclopedia/arbitrum-one/",
  "collection": "ethereum",
  "title": "What is Arbitrum One? Following a Nitro rollup transaction",
  "description": "Learn how Arbitrum One uses Nitro rollup execution, Ethereum data publication and separate cross-chain message completion.",
  "aliases": [
    "Arbitrum One explained",
    "Arbitrum Nitro rollup"
  ],
  "dates": {
    "published": "2026-10-02",
    "modified": "2026-10-02",
    "verified": "2026-10-02T19:27:58.939Z",
    "dataAsOf": "2026-10-02"
  },
  "authorship": {
    "publisher": "Degrees of Satoshi editorial project",
    "process": "AI-assisted research and drafting with a separate automated source-verification pass; no external expert or named human review is implied."
  },
  "quickAnswer": {
    "text": "Arbitrum One uses the Nitro rollup architecture to execute transactions outside Ethereum mainnet while publishing data to Ethereum and checking state assertions through its rollup protocol. The sequencer supplies quick ordering, but users should distinguish that receipt from Ethereum-backed settlement and L2-to-L1 message completion. Arbitrum One and Nova do not use identical data-availability assumptions.",
    "claimId": "arbitrum-one-quick-answer",
    "sourceIds": [
      "x425-eth-arbitrum-nitro"
    ]
  },
  "keyFacts": [
    {
      "label": "Execution",
      "value": "Nitro processes Ethereum-compatible transactions through its execution system.",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ],
      "id": "execution",
      "claimId": "arbitrum-one-fact-execution"
    },
    {
      "label": "Rollup data",
      "value": "The rollup mode posts compressed transaction data to Ethereum.",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ],
      "id": "rollup-data",
      "claimId": "arbitrum-one-fact-rollup-data"
    },
    {
      "label": "Cross-chain calls",
      "value": "L2-to-L1 messages require later confirmation and execution on L1.",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ],
      "id": "cross-chain-calls",
      "claimId": "arbitrum-one-fact-cross-chain-calls"
    }
  ],
  "prerequisites": [
    "optimistic-rollups",
    "rollup-sequencers"
  ],
  "sections": [
    {
      "id": "path",
      "heading": "Follow the transaction through ordering and publication",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ],
      "paragraphs": [
        "A sequencer receives and orders transactions, and a batch poster publishes their data to the parent chain. Nodes execute the ordered input and can challenge incorrect assertions under the rollup rules. These are separate responsibilities even when a wallet presents one confirmation label.",
        "Nitro also includes a delayed inbox path through the parent chain. That mechanism has its own timing and cost rules; it is not a promise that every transaction can bypass all delays."
      ]
    },
    {
      "id": "example",
      "heading": "A local transfer and an Ethereum withdrawal finish differently",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ],
      "paragraphs": [
        "Suppose an account sends a token to another Arbitrum One account. Both holdings remain on that network. A later withdrawal to Ethereum uses a cross-chain message whose L1 execution must become available under the protocol.",
        "The first transaction’s receipt therefore cannot prove the later mainnet payout happened. Track the message and destination transaction as separate parts of the route."
      ]
    },
    {
      "id": "comparison",
      "heading": "Keep One’s rollup mode separate from AnyTrust",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ],
      "paragraphs": [
        "Nitro is a technology family with different data-availability configurations. In rollup mode, data is published on Ethereum; AnyTrust can use a committee-backed data certificate instead. Sharing Nitro software does not erase that additional assumption.",
        "For fees, use the network’s actual estimate, which can include execution and parent-chain data costs. This article gives no fixed fee or throughput promise."
      ]
    }
  ],
  "faq": [
    {
      "question": "Does a familiar Ethereum wallet address combine my mainnet and Arbitrum balances?",
      "answer": "No. The rollup maintains separate state. Follow transactions and balances on the network where they exist.",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ]
    },
    {
      "question": "Are Arbitrum One and Nova interchangeable names?",
      "answer": "No. They are separate networks with different data-availability configurations. A transfer or deposit must target the intended network.",
      "sourceIds": [
        "x425-eth-arbitrum-nitro"
      ]
    }
  ],
  "claims": [
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      "id": "arbitrum-one-quick-answer",
      "articleSlug": "arbitrum-one",
      "statement": "Arbitrum One uses the Nitro rollup architecture to execute transactions outside Ethereum mainnet while publishing data to Ethereum and checking state assertions through its rollup protocol. The sequencer supplies quick ordering, but users should distinguish that receipt from Ethereum-backed settlement and L2-to-L1 message completion. Arbitrum One and Nova do not use identical data-availability assumptions.",
      "sourceIds": [
        "source-2d1073e5ab3a8020"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-2d1073e5ab3a8020",
          "locator": "Transaction journey; rollup; AnyTrust"
        }
      ],
      "scope": {
        "collection": "ethereum",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T19:27:58.939Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Read Nitro transaction ordering, L1 batch publication, rollup assertions, delayed inbox, L2-to-L1 calls and gas components. One uses rollup; Nova uses AnyTrust. Local finality and separately redeemed outbox message distinct. No unconditional instant censorship bypass or fixed cost quoted."
        ]
      }
    },
    {
      "id": "arbitrum-one-fact-execution",
      "articleSlug": "arbitrum-one",
      "statement": "Execution: Nitro processes Ethereum-compatible transactions through its execution system.",
      "sourceIds": [
        "source-2d1073e5ab3a8020"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-2d1073e5ab3a8020",
          "locator": "Transaction journey; rollup; AnyTrust"
        }
      ],
      "scope": {
        "collection": "ethereum",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T19:27:58.939Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Read Nitro transaction ordering, L1 batch publication, rollup assertions, delayed inbox, L2-to-L1 calls and gas components. One uses rollup; Nova uses AnyTrust. Local finality and separately redeemed outbox message distinct. No unconditional instant censorship bypass or fixed cost quoted."
        ]
      }
    },
    {
      "id": "arbitrum-one-fact-rollup-data",
      "articleSlug": "arbitrum-one",
      "statement": "Rollup data: The rollup mode posts compressed transaction data to Ethereum.",
      "sourceIds": [
        "source-2d1073e5ab3a8020"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-2d1073e5ab3a8020",
          "locator": "Transaction journey; rollup; AnyTrust"
        }
      ],
      "scope": {
        "collection": "ethereum",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T19:27:58.939Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Read Nitro transaction ordering, L1 batch publication, rollup assertions, delayed inbox, L2-to-L1 calls and gas components. One uses rollup; Nova uses AnyTrust. Local finality and separately redeemed outbox message distinct. No unconditional instant censorship bypass or fixed cost quoted."
        ]
      }
    },
    {
      "id": "arbitrum-one-fact-cross-chain-calls",
      "articleSlug": "arbitrum-one",
      "statement": "Cross-chain calls: L2-to-L1 messages require later confirmation and execution on L1.",
      "sourceIds": [
        "source-2d1073e5ab3a8020"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-2d1073e5ab3a8020",
          "locator": "Transaction journey; rollup; AnyTrust"
        }
      ],
      "scope": {
        "collection": "ethereum",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
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        "checkedAt": "2026-10-02T19:27:58.939Z",
        "reviewer": "Independent automated verification agent verify_bitcoin_stablecoins_100",
        "notes": [
          "Read Nitro transaction ordering, L1 batch publication, rollup assertions, delayed inbox, L2-to-L1 calls and gas components. One uses rollup; Nova uses AnyTrust. Local finality and separately redeemed outbox message distinct. No unconditional instant censorship bypass or fixed cost quoted."
        ]
      }
    }
  ],
  "sources": [
    {
      "id": "x425-eth-arbitrum-nitro",
      "label": "Inside Arbitrum Nitro",
      "publisher": "Offchain Labs",
      "url": "https://docs.arbitrum.io/how-arbitrum-works/inside-arbitrum-nitro",
      "locator": "Transaction journey; rollup; AnyTrust",
      "note": "Nitro rollup execution and Ethereum batch publication versus AnyTrust committee assumptions.",
      "version": "Documentation snapshot retrieved 2 October 2026; response hash recorded separately",
      "checkedAt": "2026-10-02T18:55:27.094Z",
      "contentSha256": "b0e9819a15eacadbab163dd3255ded4025880453fde823e0aa5df2ff03d83990",
      "recordId": "source-2d1073e5ab3a8020"
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  ],
  "related": {
    "articles": [
      "optimistic-rollups",
      "rollup-sequencers",
      "ethereum-blob-fees",
      "base-network",
      "optimism-op-mainnet"
    ],
    "dossiers": [],
    "wallets": []
  },
  "revisionHistory": [
    {
      "date": "2026-10-02",
      "kind": "published",
      "summary": "First publication after primary-source research and separate automated verification."
    }
  ],
  "citation": "Degrees of Satoshi editorial project. “What is Arbitrum One? Following a Nitro rollup transaction.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/arbitrum-one/"
}