diff --git a/contracts/bridge/script/Install.s.sol b/contracts/bridge/script/Install.s.sol
new file mode 100644
index 000000000..27af575b0
--- /dev/null
+++ b/contracts/bridge/script/Install.s.sol
@@ -0,0 +1,37 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+import {Vm, VM_ADDRESS} from "../test/Vm.sol";
+import {IgneumCertificateVerifier} from "../src/IgneumCertificateVerifier.sol";
+
+/// Installs (or replaces) the voter table on an already deployed verifier (BRIDGE_VERIFIER) from the vectors file in
+/// BRIDGE_TABLE_JSON (a gen.mjs table or chain output: keys, weights, index) and, when the file carries a certificate
+/// (bitmap, signature), submits it. The deployer key comes from BRIDGE_DEPLOYER_KEY in the environment, never printed.
+/// Used for a chain whose table is read at its first lock, after the contract itself was deployed (8 October 2026,
+/// igneum-devnet-4: the contract first, the table when the weight window filled).
+///
+///   BRIDGE_VERIFIER=0x.. BRIDGE_TABLE_JSON=test/vectors/dn4-table.json forge script script/Install.s.sol:Install --rpc-url sepolia --broadcast --sig "run()"
+contract Install {
+    Vm constant vm = Vm(VM_ADDRESS);
+
+    function run() external {
+        uint256 key = vm.envUint("BRIDGE_DEPLOYER_KEY");
+        IgneumCertificateVerifier v = IgneumCertificateVerifier(vm.envAddress("BRIDGE_VERIFIER"));
+        string memory j = vm.readFile(vm.envOr("BRIDGE_TABLE_JSON", "test/vectors/dn4-table.json"));
+        bytes[] memory keys = vm.parseJsonBytesArray(j, ".keys");
+        uint256[] memory w = vm.parseJsonUintArray(j, ".weights");
+        bytes memory packed;
+        uint64[] memory weights = new uint64[](w.length);
+        for (uint256 i = 0; i < keys.length; i++) {
+            packed = abi.encodePacked(packed, keys[i]);
+            weights[i] = uint64(w[i]);
+        }
+        uint64 index = uint64(vm.parseJsonUint(j, ".index"));
+        vm.startBroadcast(key);
+        v.installTable(index, packed, weights);
+        if (vm.keyExistsJson(j, ".bitmap")) {
+            v.submitCertificate(index, vm.parseJsonBytes32(j, ".checkpoint"), vm.parseJsonBytes(j, ".bitmap"), vm.parseJsonBytes(j, ".signature"));
+        }
+        vm.stopBroadcast();
+    }
+}
diff --git a/docs/contracts/sepolia.json b/docs/contracts/sepolia.json
index d2034bc63..337480401 100644
--- a/docs/contracts/sepolia.json
+++ b/docs/contracts/sepolia.json
@@ -48,6 +48,18 @@
           "caveat": "the root is the chain's own but no certificate ties it to a checkpoint (gap 1 in docs/bridge/light-client-bridge.md)"
         }
       ]
+    },
+    "IgneumCertificateVerifier_devnet4": {
+      "address": "0x874D8Be5385474414aeb69EE4AB8374DA34b8c1F",
+      "create_tx": "0x943b6050602ce0dc9318f1b9a53ed79bf04c1bd9c60a22de2aac65c566f84ecc",
+      "igneum_chain_id": "igneum-devnet-4",
+      "evm_chain_id": 4465,
+      "deployer": "0x70e692A9f1fa1067a8c2d64fDAf1636b4EAEC7e2",
+      "deployed_at": "2026-10-08T17:2xZ (build-4; build-3 down from 15:40Z with the first deployer key on its disk)",
+      "table": "not installed yet: devnet-4's voter table is read from igneum_getFinalityWeights at the chain's first finality lock (the 7,200-DAA window filling at about 15 DAA a minute from 2,626 at 16:5xZ, so about 22:00Z) and installed through contracts/bridge/script/Install.s.sol",
+      "final_checkpoints": "none yet",
+      "shared_with": "the reference-apps lane's IgneumStateOracle for devnet-4, 0xbb3450049926da3572e6b67cb94df312fe349e34 (setVerifier)",
+      "note": "Igneum 2.0 (8 October 2026, 17:45 BST): Devnet 3 switched off, igneum-devnet-4 is the 2.0 devnet; the Devnet 3 verifier above keeps its recorded checkpoint and account proof as the record"
     }
   },
   "first_deploy_note": "A first creation at 0xD7dd375E14F92A4CE4782040325189e6d6E394b6 (tx 0x4db10565\u2026, block 11869633) ran out of gas at Foundry's Prague-spec estimate of 3,323,884; Sepolia runs Osaka pricing (EIP-7883 modexp), so the test EVM and the deploy now use osaka and the RPC's own estimate. That address holds no code.",