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  "id": "article.recheck-chain-after-network-change",
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  "title": "Changed Networks? Recheck the Chain Before Reusing a Token Report",
  "slug": "recheck-chain-after-network-change",
  "category": "wallet_workflow",
  "intent": "Help a reader decide whether an existing token report applies after changing the network selected in a wallet or RPC provider.",
  "directAnswer": "Read the provider's chain ID again after a network change, then compare it with the chain named in the report. Base Mainnet and Base Sepolia have different IDs. A report about one network does not establish facts about the other; matching the network is only the first context check, alongside the contract address and observation time.",
  "sections": [
    {
      "heading": "Read the identifier, not just the network label",
      "paragraphs": [
        "[EIP-695](https://eips.ethereum.org/EIPS/eip-695) defines `eth_chainId` as the way to read the configured chain ID. Its result is a hexadecimal representation of an integer. The specification recommends using it rather than `net_version` to identify the chain being contacted. For a reader comparing a provider with a saved report, the useful question is whether their chain identities match, not whether two interfaces display a similar name."
      ]
    },
    {
      "heading": "Base Mainnet and Sepolia are different contexts",
      "paragraphs": [
        "[Base's method reference](https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_chainId) gives these documented values:\n\n| Network | Hexadecimal chain ID | Decimal chain ID |\n| --- | --- | --- |\n| Base Mainnet | `0x2105` | `8453` |\n| Base Sepolia | `0x14a34` | `84532` |\n\nThe decimal and hexadecimal entries in each row are two representations of the same identifier. The rows describe separate networks. These are documentation values, not readings from your wallet."
      ]
    },
    {
      "heading": "A changed account is a different signal",
      "paragraphs": [
        "[EIP-1193](https://eips.ethereum.org/EIPS/eip-1193) separates `chainChanged`, which reports the provider's connected chain changing, from `accountsChanged`, which reports a change to the accounts available to it. Seeing an account update therefore does not establish that the chain stayed the same. The standard also requires the provider's `eth_chainId` result to reflect its configured chain. This describes the interface contract; it does not verify how a particular wallet behaves."
      ]
    },
    {
      "heading": "Use a report-context checklist after a switch",
      "paragraphs": [
        "The following is a practical reading workflow derived from those interface definitions:\n\n- Read the chain ID again and compare it with the report's stated network.\n- Compare the exact contract address in the report with the asset you intend to inspect on that chain.\n- Check the report's observation time and any missing-source notices.\n- If the chain differs, stop using that report as evidence for the newly selected network and request a report with the correct scope.\n\nA matching network is necessary context, not a conclusion about the asset. Keep those decisions separate."
      ]
    },
    {
      "heading": "Switching back does not update an old report",
      "paragraphs": [
        "Returning to the original network can resolve an identity mismatch. It does not, by itself, collect fresh observations or complete a missing check in a saved report. Keep the network comparison separate from the report's date and source coverage. Our [guide to token data quality](https://jepeta.dev/guides/what-does-token-data-quality-mean/) explains how to read missing and partial evidence; this checklist adds the network-switch question before that review."
      ]
    },
    {
      "heading": "What this check can establish",
      "paragraphs": [
        "The documented chain ID can help identify which network a provider is configured to contact. It cannot establish the truth of every response returned through that provider or determine whether a token is suitable for a transaction. This article compares published specifications and documentation. No wallet was connected, no transaction was signed, and no specific token was evaluated."
      ]
    }
  ],
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    {
      "id": "eip695",
      "label": "EIP-695: eth_chainId",
      "url": "https://eips.ethereum.org/EIPS/eip-695",
      "sourceType": "primary",
      "publishedAt": null,
      "verifiedAt": "2026-10-18T02:23:15.170Z"
    },
    {
      "id": "eip1193",
      "label": "EIP-1193: provider events",
      "url": "https://eips.ethereum.org/EIPS/eip-1193",
      "sourceType": "primary",
      "publishedAt": null,
      "verifiedAt": "2026-10-18T02:23:15.170Z"
    },
    {
      "id": "base_chainid",
      "label": "Base: documented chain IDs",
      "url": "https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_chainId",
      "sourceType": "primary",
      "publishedAt": null,
      "verifiedAt": "2026-10-18T02:23:15.170Z"
    },
    {
      "id": "jepeta_quality",
      "label": "Jepeta: data quality and source completeness",
      "url": "https://jepeta.dev/guides/what-does-token-data-quality-mean/",
      "sourceType": "jepeta",
      "publishedAt": null,
      "verifiedAt": "2026-10-18T02:24:59.823Z"
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  ],
  "sourceDates": [
    {
      "sourceId": "eip695",
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      "verifiedAt": "2026-10-18T02:23:15.170Z"
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  "originalEvidence": [
    {
      "type": "source_audit",
      "description": "Compared the chain-identity method, provider event definitions and Base network values; independently recomputed both hexadecimal/decimal mappings and derived a report-applicability checklist. No live wallet or transaction test is claimed.",
      "url": "https://docs.base.org/base-chain/api-reference/ethereum-json-rpc-api/eth_chainId",
      "observedAt": "2026-10-18T02:23:15.170Z"
    }
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  "datePublished": "2026-10-18T02:23:15.170Z",
  "dateModified": "2026-10-18T02:25:08.905Z",
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  "disclosure": "AI-assisted educational explanation. The cited source definitions and chain-ID conversions were checked for this edition. No wallet session or transaction was performed.",
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  "seoTitle": "Network Changed? Check Chain ID Before Reusing a Token Report",
  "metaDescription": "Compare Base Mainnet and Sepolia chain IDs, distinguish wallet events, and check whether a saved token report still matches your selected network.",
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    "alt": "Conceptual comparison of Base Mainnet and Sepolia chain IDs before reusing a saved report",
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