From 5f9273855f8a62dccd346fe849619a139c3f430c Mon Sep 17 00:00:00 2001
From: Pavel Shuvalov <shuvalov.pavel@gmail.com>
Date: Sat, 25 Jul 2026 11:10:52 +0100
Subject: [PATCH]  Fix: v4 `action` mapping must be reduced to a field element

---
 world-id/idkit/onchain-verification.mdx | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/world-id/idkit/onchain-verification.mdx b/world-id/idkit/onchain-verification.mdx
index cae8f7d..c348843 100644
--- a/world-id/idkit/onchain-verification.mdx
+++ b/world-id/idkit/onchain-verification.mdx
@@ -165,7 +165,7 @@ contract VerifyUniquenessV4 {
 
 Minimal mapping from IDKit result:
 - `nullifier` = `responses[i].nullifier`
-- `action` = `keccak256(action)` as `uint256`
+- `action` = `hashToField(action)`, i.e. `uint256(keccak256(action)) >> 8`
 - `rpId` = numeric form of your `rp_context.rp_id` (the `rp_`-prefixed string from your RP context, not the result)
 - `nonce` = top-level `nonce`
 - `signalHash` = `responses[i].signal_hash`