{
  "id": 7843,
  "title": "EIP-7843: SLOTNUM opcode",
  "status": "Draft",
  "type": "Standards Track",
  "category": "Core",
  "summary": "Let contracts directly read the current slot number cheaply, removing timestamp math and reducing breakage if Ethereum's slot duration changes later.",
  "impacts": [
    "Indirectly benefits from more reliable app timing if slot duration changes in future networks.",
    "Simplifies reading beacon time onchain, avoiding timestamp math and EIP-4788 proofs; fewer assumptions about the slot schedule.",
    "Little to no impact; wallets typically don't consume slot numbers. Optional UI or simulation support could display it.",
    "Block explorers, RPC simulators, and debuggers may add opcode support and parse the new header slot_number field.",
    "Optional support; helpful if mirroring L1 semantics. Not required unless chains want SLOTNUM compatibility and header field parity.",
    "No operational changes expected; clients handle computation and propagation. Node operators shouldn't need configuration or workflow updates.",
    "Must compute slot_number and include it in headers and engine API payloads; aligns with existing consensus-layer slot calculations.",
    "Implement new opcode, validate header field, expose via RPC, and price gas; updates required across execution clients.",
    "Removes hardcoded slot assumptions; apps remain correct if slot duration changes.",
    "Cheaper than proving slot via EIP-4788; simple 2-gas opcode call.",
    "Slot number available directly in block header and engine API.",
    "No added proving complexity; similar to TIMESTAMP for ZK-VMs."
  ],
  "discussion_url": "https://ethereum-magicians.org/t/eip-7843-slotnum-opcode/22234",
  "source_markdown_url": "https://github.com/ethereum/EIPs/blob/master/EIPS/eip-7843.md",
  "canonical_url": "/latest/eips/7843.json",
  "markdown_url": "/latest/eips/7843.md",
  "citations": [
    {
      "recordId": "eip-7843",
      "artifactPath": "normalized/7843.json",
      "url": "/records/proposal/eip-7843/normalized/7843.json",
      "label": "EIP-7843: SLOTNUM opcode",
      "snippet": "Let contracts directly read the current slot number cheaply, removing timestamp math and reducing breakage if Ethereum's slot duration changes later."
    }
  ]
}