Eclair Dual-Fund Errors - Fix Interactive Channel Opening Issues

What Is Eclair Dual-Funding?

Dual-funded channels (BOLT2 interactive tx) allow both peers to contribute funds at channel open. This improves inbound liquidity without separate rebalancing.

Common Errors

• dual_fund not supported by peer
• InteractiveTxError: invalid tx_add_input
• DualFundFailed: funding timeout
• rbf attempt rejected by peer

Enable Dual-Funding in Eclair

# In eclair.conf
eclair.features.option_dual_fund = optional

# Or force it on
eclair.features.option_dual_fund = mandatory

Open a Dual-Funded Channel

# Open with your contribution + request peer contribution
curl -u :password -X POST http://localhost:8080/open \
  -d nodeId=<peer_pubkey> \
  -d fundingSatoshis=500000 \
  -d pushMsat=0 \
  -d requestFunding=200000

Debugging

• Check peer features: GET /peers and look for option_dual_fund
• Funding timeout: increase eclair.bitcoind.zmqtxhash poll frequency
• RBF rejected: peer may not support option_rbf alongside dual_fund

Eclair dual-fund issues? DM on Nostr for a free diagnostic.