phoenixd (ACINQ)

phoenixd is the headless version of the Phoenix wallet. Designed for individuals and small services who want a self-hosted LN daemon without the operational complexity of LND/CLN.

Phoenix mobile = consumer wallet. phoenixd = same engine, no UI, HTTP API for integration.

Architecture

Built on top of Eclair core (so JVM-based).
Self-hosts; single node, no cluster.
Auto-channel management via ACINQ swap-in / swap-out.
Default to BOLT12 offers for receiving.
Lightning-Address support out of the box.

Why phoenixd

No bitcoind required — uses Electrum servers (configurable).
No on-chain wallet UI — auto-handles funding and channel mgmt.
API-first — HTTP REST + WebSocket for payment events.
Reasonable defaults — anchor channels, MPP, BOLT12, all enabled by default.
Liquidity from ACINQ — auto channel-open via swap-in.

Install

curl -L https://github.com/ACINQ/phoenixd/releases/download/.../phoenixd-... > phoenixd.zip
unzip phoenixd.zip; cd phoenixd-...

./phoenixd --version
./phoenixd        # first run: generates seed, prompts to backup

Config at ~/.phoenix/phoenix.conf:

chain=mainnet
http-bind-ip=127.0.0.1
http-bind-port=9740
http-password=<auto-generated, in seed.dat or set explicitly>
auto-liquidity=2m   # auto manage liquidity, allow 2M sats inbound

API

Default localhost:9740. Auth via HTTP basic (_:<password>):

curl -u _:$(cat ~/.phoenix/phoenix.conf | grep http-password | cut -d= -f2) \
  http://127.0.0.1:9740/getinfo

curl -u _:pass -X POST -d "amountSat=5000&description=Coffee" \
  http://127.0.0.1:9740/createinvoice

curl -u _:pass -X POST -d "invoice=lnbc..." \
  http://127.0.0.1:9740/payinvoice

WebSocket events

Real-time payment notifications:

const ws = new WebSocket("ws://_:pass@127.0.0.1:9740/websocket");
ws.onmessage = (e) => {
    const event = JSON.parse(e.data);
    if (event.type === "payment-received") {
        console.log("Got", event.amountSat, "sats");
    }
};

Liquidity

phoenixd auto-manages liquidity via ACINQ:

Splice-in: when more inbound liquidity needed.
Splice-out: when receiving on-chain back.
Fees charged by ACINQ (typically small percentage of channel size).

For higher volume, run alongside LSP:

liquidity-provider=acinq    # default

Use cases

Self-hosted POS terminals (Donation page, micro-merchant).
Private API for backends (no need for LND complexity).
Lightning Address servers (low setup overhead).
Integration with NWC providers.

Limitations

Only one channel at a time (vs LND/CLN which support many).
ACINQ as sole LSP (others possible but tested less).
No BOLT12 send in some early versions (check current docs).
Eclair lineage: heavy JVM, ~500 MB RAM.

Backup

~/.phoenix/seed.dat is the seed (encrypted with empty password unless set). Backup this file + phoenix.conf.

Channel state recovery: if seed restored to a different machine, phoenixd attempts to recover via SCB-like flow with peers.

Comparison

Feature	phoenixd	LND	CLN	LDK Node
Setup complexity	★ (very simple)	★★★★	★★★	★★
Multiple channels	no	yes	yes	yes
Plugin ecosystem	no	rich	rich	code-level
Memory	~500 MB	100-200 MB	~150 MB	10-50 MB
LSP integration	ACINQ-native	manual	manual	flexible
BOLT12 receive	yes	partial	yes	yes

lightning-phoenixd