bug: Swap demo fails with 'EIP-7702 not supported on chain' error

[gakonst]

Description

The swap demo at https://docs.tempo.xyz/guide/stablecoin-dex/executing-swaps fails with the following error when attempting to sign up or make a swap:

This Wallet does not support the requested chain ID.
Request Arguments: from: 0xADBCb707651C88223362c536359b89271B894923
Details: EIP-7702 not supported on chain: 0xa5bf
Version: viem@2.44.4

Environment

• Chain: tempoModerato (Chain ID: 42431 / 0xa5bf)
• viem: 2.44.4
• wagmi: 3.4.1
• Connector: webAuthn with grantAccessKey: true

Investigation Summary

The T0 hardfork (which enables proper EIP-7702 support) was merged in PR #2008 on Jan 13, 2026 and should now be active on Moderato.

Possible causes:

1. Stale deployment of the docs site or fee-payer service
2. Caching issue
3. RPC node configuration issue

Reproduction

1. Go to https://docs.tempo.xyz/guide/stablecoin-dex/executing-swaps
2. Click "Sign up" in the demo
3. After creating a passkey, attempt any action (Fund Account, Buy, etc.)
4. Observe the error

References

• T0 hardfork PR: fix! : apply 1987 fixes with T0 hardfork gating tempo#2008
• Access key fix PR: fix! : access keys from 7702 delegating accounts tempo#1990
• Tweet reporting issue: https://x.com/lahilapagi/status/2015435370088079462

[deodad]

this didn't repro for me—will have someone else try it out and close as fixed if same result