{
  "$schema": "https://degreesofsatoshi.com/encyclopedia/schemas/article-v1.json",
  "schemaVersion": "1.0.0",
  "id": "lightning-watchtowers",
  "canonical": "https://degreesofsatoshi.com/encyclopedia/lightning-watchtowers/",
  "collection": "bitcoin",
  "title": "Lightning watchtowers: monitoring channels while a wallet is offline",
  "description": "Understand Lightning watchtowers, the revoked-state problem they monitor and why they do not replace backups or guarantee payment availability.",
  "aliases": [
    "lightning watchtower",
    "lightning watchtower explained"
  ],
  "dates": {
    "published": "2026-10-02",
    "modified": "2026-10-02",
    "verified": "2026-10-02T19:29:20.637Z",
    "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": "A Lightning watchtower monitors the blockchain for a specific kind of channel breach: a counterparty publishing an old, revoked commitment. With the necessary information, it can submit the protective transaction while the user’s node is offline. It does not recover every lost wallet, provide missing routing liquidity or ensure that every payment succeeds. Its protection depends on the tower setup, channel design and timely on-chain action.",
    "claimId": "lightning-watchtowers-quick-answer",
    "sourceIds": [
      "x425-btc-ln-watchtowers",
      "x425-btc-bolt3"
    ]
  },
  "keyFacts": [
    {
      "label": "Threat watched",
      "value": "Publication of a revoked channel state",
      "sourceIds": [
        "x425-btc-ln-watchtowers"
      ],
      "id": "threat-watched",
      "claimId": "lightning-watchtowers-fact-threat-watched"
    },
    {
      "label": "Protection path",
      "value": "An on-chain response within applicable constraints",
      "sourceIds": [
        "x425-btc-ln-watchtowers",
        "x425-btc-bolt3"
      ],
      "id": "protection-path",
      "claimId": "lightning-watchtowers-fact-protection-path"
    },
    {
      "label": "Separate need",
      "value": "Wallet and channel recovery backups",
      "sourceIds": [
        "x425-btc-ln-recovery"
      ],
      "id": "separate-need",
      "claimId": "lightning-watchtowers-fact-separate-need"
    }
  ],
  "prerequisites": [
    "lightning-payment-channels",
    "bitcoin-timelocks"
  ],
  "sections": [
    {
      "id": "breach",
      "heading": "Why an old agreement needs a response",
      "sourceIds": [
        "x425-btc-ln-watchtowers",
        "x425-btc-ln-lifecycle"
      ],
      "paragraphs": [
        "In the documented penalty-channel design, updated commitments supersede earlier agreements. Publishing a revoked state can trigger a penalty response. The affected party must detect the breach and act before the counterparty’s delayed output becomes spendable.",
        "A watchtower can perform that monitoring role using prepared, encrypted information. The exact information it receives and the response it can make depend on the implementation."
      ]
    },
    {
      "id": "example",
      "heading": "A delay measured in blocks is not a fixed number of hours",
      "sourceIds": [
        "x425-btc-ln-watchtowers",
        "x425-btc-bolt3",
        "x425-btc-whitepaper"
      ],
      "paragraphs": [
        "Suppose a relevant delay is 144 blocks. At an assumed average of ten minutes per block, that corresponds to 24 hours on average. Actual blocks arrive irregularly, so it is not a guaranteed 24-hour response window.",
        "The tower must be available and able to get the protective transaction confirmed under the relevant conditions. Merely entering a tower address in an interface is not evidence that current channels are covered."
      ]
    },
    {
      "id": "limits",
      "heading": "Keep monitoring separate from recovery and routing",
      "sourceIds": [
        "x425-btc-ln-watchtowers",
        "x425-btc-ln-recovery",
        "x425-btc-ln-payments"
      ],
      "paragraphs": [
        "A tower is not a substitute for the seed and channel backup required after device loss. It also does not keep every peer online, create receiving capacity or repair an invalid invoice.",
        "Check the implementation’s coverage and connection status, and keep its normal backup process. The cited LND-oriented guide explains one tower design; other channel and wallet designs can have different requirements."
      ]
    }
  ],
  "faq": [
    {
      "question": "Can a watchtower restore my missing seed?",
      "answer": "No. Its breach-monitoring role is different from key recovery. Keep the recovery material required by the wallet and implementation.",
      "sourceIds": [
        "x425-btc-ln-watchtowers",
        "x425-btc-ln-recovery"
      ]
    },
    {
      "question": "Does a watchtower make all offline Lightning payments work?",
      "answer": "No. Monitoring for revoked commitments does not supply an online payment recipient or a usable payment route. Payment availability is a separate issue.",
      "sourceIds": [
        "x425-btc-ln-watchtowers",
        "x425-btc-ln-cycle"
      ]
    }
  ],
  "claims": [
    {
      "id": "lightning-watchtowers-quick-answer",
      "articleSlug": "lightning-watchtowers",
      "statement": "A Lightning watchtower monitors the blockchain for a specific kind of channel breach: a counterparty publishing an old, revoked commitment. With the necessary information, it can submit the protective transaction while the user’s node is offline. It does not recover every lost wallet, provide missing routing liquidity or ensure that every payment succeeds. Its protection depends on the tower setup, channel design and timely on-chain action.",
      "sourceIds": [
        "source-c990c3514ba7948d",
        "source-b886d1d57cf59732"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-c990c3514ba7948d",
          "locator": "Channel breaches; Watchtowers; Timelocks"
        },
        {
          "sourceId": "source-b886d1d57cf59732",
          "locator": "Commitment Transaction; HTLC Outputs; Closing Transaction"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "Educational explanation. Product-specific behavior is scoped to the cited documentation, checked 2026-10-02.",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T19:29:20.637Z",
        "reviewer": "Independent automated verification — Codex /root/verify_ethereum_100, separate from the Bitcoin drafting agent",
        "notes": [
          "Checked Lightning Labs watchtower mechanism and BOLT3 delayed/revocation paths.144blocks=24hours only under the stated average; preparation, coverage and timely confirmation remain conditions. Watchtowers are not seed recovery or payment routing."
        ]
      }
    },
    {
      "id": "lightning-watchtowers-fact-threat-watched",
      "articleSlug": "lightning-watchtowers",
      "statement": "Threat watched: Publication of a revoked channel state",
      "sourceIds": [
        "source-c990c3514ba7948d"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-c990c3514ba7948d",
          "locator": "Channel breaches; Watchtowers; Timelocks"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
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        "checkedAt": "2026-10-02T19:29:20.637Z",
        "reviewer": "Independent automated verification — Codex /root/verify_ethereum_100, separate from the Bitcoin drafting agent",
        "notes": [
          "Checked Lightning Labs watchtower mechanism and BOLT3 delayed/revocation paths.144blocks=24hours only under the stated average; preparation, coverage and timely confirmation remain conditions. Watchtowers are not seed recovery or payment routing."
        ]
      }
    },
    {
      "id": "lightning-watchtowers-fact-protection-path",
      "articleSlug": "lightning-watchtowers",
      "statement": "Protection path: An on-chain response within applicable constraints",
      "sourceIds": [
        "source-c990c3514ba7948d",
        "source-b886d1d57cf59732"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-c990c3514ba7948d",
          "locator": "Channel breaches; Watchtowers; Timelocks"
        },
        {
          "sourceId": "source-b886d1d57cf59732",
          "locator": "Commitment Transaction; HTLC Outputs; Closing Transaction"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
        "status": "verified",
        "method": "independent automated source review",
        "checkedAt": "2026-10-02T19:29:20.637Z",
        "reviewer": "Independent automated verification — Codex /root/verify_ethereum_100, separate from the Bitcoin drafting agent",
        "notes": [
          "Checked Lightning Labs watchtower mechanism and BOLT3 delayed/revocation paths.144blocks=24hours only under the stated average; preparation, coverage and timely confirmation remain conditions. Watchtowers are not seed recovery or payment routing."
        ]
      }
    },
    {
      "id": "lightning-watchtowers-fact-separate-need",
      "articleSlug": "lightning-watchtowers",
      "statement": "Separate need: Wallet and channel recovery backups",
      "sourceIds": [
        "source-b441602c23e09691"
      ],
      "sourceLocators": [
        {
          "sourceId": "source-b441602c23e09691",
          "locator": "aezeed; Static channel backups (SCB); Channel Database"
        }
      ],
      "scope": {
        "collection": "bitcoin",
        "dataAsOf": "2026-10-02",
        "blockHeight": null
      },
      "qualification": "",
      "evidenceStatus": "documented",
      "verification": {
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        "checkedAt": "2026-10-02T19:29:20.637Z",
        "reviewer": "Independent automated verification — Codex /root/verify_ethereum_100, separate from the Bitcoin drafting agent",
        "notes": [
          "Checked Lightning Labs watchtower mechanism and BOLT3 delayed/revocation paths.144blocks=24hours only under the stated average; preparation, coverage and timely confirmation remain conditions. Watchtowers are not seed recovery or payment routing."
        ]
      }
    }
  ],
  "sources": [
    {
      "id": "x425-btc-ln-watchtowers",
      "label": "Watchtowers",
      "publisher": "Lightning Labs",
      "url": "https://raw.githubusercontent.com/lightninglabs/docs.lightning.engineering/0456e1627b2579ac18108cb921fe609f87c8b009/the-lightning-network/payment-channels/watchtowers.md",
      "locator": "Channel breaches; Watchtowers; Timelocks",
      "note": "Monitoring revoked channel states and limitations of outsourced breach protection.",
      "version": "Pinned Lightning Labs documentation revision; LND/Loop implementation scope",
      "checkedAt": "2026-10-02T18:53:57.295Z",
      "contentSha256": "5a3fbe26cb7b1adae82c5a375139a7a6284cfd85f874fcb55b9a61d8a1b47513",
      "recordId": "source-c990c3514ba7948d"
    },
    {
      "id": "x425-btc-bolt3",
      "label": "BOLT 3: Bitcoin Transaction and Script Formats",
      "publisher": "Lightning specification contributors",
      "url": "https://raw.githubusercontent.com/lightning/bolts/1aadb719b4007c4cea0ba6e36b08c4fb53788dee/03-transactions.md",
      "locator": "Commitment Transaction; HTLC Outputs; Closing Transaction",
      "note": "Commitment output delays and conditional HTLC settlement on chain.",
      "version": "Pinned BOLTs revision",
      "checkedAt": "2026-10-02T18:53:57.097Z",
      "contentSha256": "27ffbf1ae436f257bff3f255b4d1e4d4bbf8597fb1e2533d7ff9b66f4fe38d43",
      "recordId": "source-b886d1d57cf59732"
    },
    {
      "id": "x425-btc-ln-recovery",
      "label": "Recovery: Planning for Failure",
      "publisher": "Lightning Labs",
      "url": "https://raw.githubusercontent.com/lightninglabs/docs.lightning.engineering/0456e1627b2579ac18108cb921fe609f87c8b009/lightning-network-tools/lnd/recovery-planning-for-failure.md",
      "locator": "aezeed; Static channel backups (SCB); Channel Database",
      "note": "LND seed, static channel backups, safe channel recovery and external backups.",
      "version": "Pinned Lightning Labs documentation revision; LND/Loop implementation scope",
      "checkedAt": "2026-10-02T18:53:57.272Z",
      "contentSha256": "016d77748e9a725ee012189116d9aec9d3aade08d671f2548bfee5b9d6438d79",
      "recordId": "source-b441602c23e09691"
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    {
      "id": "x425-btc-ln-lifecycle",
      "label": "The lifecycle of a payment channel",
      "publisher": "Lightning Labs",
      "url": "https://raw.githubusercontent.com/lightninglabs/docs.lightning.engineering/0456e1627b2579ac18108cb921fe609f87c8b009/the-lightning-network/payment-channels/lifecycle-of-a-payment-channel.md",
      "locator": "Opening a channel; Sending funds through a payment channel; Closing a channel; Cooperatively; Non-cooperatively",
      "note": "Cooperative versus unilateral closes and confirmation/delay requirements.",
      "version": "Pinned Lightning Labs documentation revision; LND/Loop implementation scope",
      "checkedAt": "2026-10-02T18:53:57.295Z",
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      "recordId": "source-d0625e6983c0ac55"
    },
    {
      "id": "x425-btc-whitepaper",
      "label": "Bitcoin: A Peer-to-Peer Electronic Cash System",
      "publisher": "Satoshi Nakamoto",
      "url": "https://bitcoin.org/bitcoin.pdf",
      "locator": "Sections 4, 6, 7, 10 and 11",
      "note": "Independent hash attempts, incentives, transaction collaboration limits and Poisson block-arrival approximation.",
      "version": "2008 paper",
      "checkedAt": "2026-10-02T18:53:58.187Z",
      "contentSha256": "b1674191a88ec5cdd733e4240a81803105dc412d6c6708d53ab94fc248f4f553",
      "recordId": "source-0e46aca4dbc5a030"
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    {
      "id": "x425-btc-ln-payments",
      "label": "Sending Payments",
      "publisher": "Lightning Labs",
      "url": "https://raw.githubusercontent.com/lightninglabs/docs.lightning.engineering/0456e1627b2579ac18108cb921fe609f87c8b009/lightning-network-tools/lnd/payments.md",
      "locator": "Pathfinding; Dispatching Payments; Payment Fees; Monitoring Payments",
      "note": "LND initiated/in-flight/succeeded/failed statuses and safe retry semantics.",
      "version": "Pinned Lightning Labs documentation revision; LND/Loop implementation scope",
      "checkedAt": "2026-10-02T18:53:57.437Z",
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      "id": "x425-btc-ln-cycle",
      "label": "The payment cycle",
      "publisher": "Lightning Labs",
      "url": "https://raw.githubusercontent.com/lightninglabs/docs.lightning.engineering/0456e1627b2579ac18108cb921fe609f87c8b009/the-lightning-network/multihop-payments/the-payment-cycle.md",
      "locator": "Introduction: sender and receiver interaction; Create invoice; Make the payment; Check the payment; Other payment types",
      "note": "Invoice-first Lightning flow, routes and settlement preimages.",
      "version": "Pinned Lightning Labs documentation revision; LND/Loop implementation scope",
      "checkedAt": "2026-10-02T18:53:57.281Z",
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  "related": {
    "articles": [
      "lightning-payment-channels",
      "bitcoin-timelocks",
      "lightning-channel-backups",
      "lightning-force-close"
    ],
    "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. “Lightning watchtowers: monitoring channels while a wallet is offline.” Published 2026-10-02; updated 2026-10-02. https://degreesofsatoshi.com/encyclopedia/lightning-watchtowers/"
}