# ACINQ

> ACINQ is a Paris-based Bitcoin technology company and one of the principal implementers
> of the Lightning Network. It publishes two documented HTTP APIs — the phoenixd API (27
> endpoints, for merchants and applications that need to send and receive Lightning
> payments self-custodially) and the eclair JSON API (56 methods, for running and managing
> a full routing node) — plus Kotlin Multiplatform libraries on Maven Central. Both APIs
> are SELF-HOSTED daemons: you run the software, so the base URL is your own host, and
> there is no vendor endpoint, no signup and no API key to obtain.

GENERATED by the API Evangelist enrichment pipeline on 2026-08-17. ACINQ does not publish
an llms.txt of its own (https://acinq.co/llms.txt returns 404;
https://phoenix.acinq.co/llms.txt returns 403). This file is an independent third-party
index, not an ACINQ document.

## Key facts an agent should know first

- There is NO OpenAPI, Swagger, GraphQL SDL, AsyncAPI, MCP server or Postman collection
  published by ACINQ. Both API references are hand-written documentation.
- Both APIs are self-hosted. phoenixd binds to 127.0.0.1:9740 by default; eclair to
  port 8080. ACINQ documents explicitly that neither should be exposed to the internet.
- Authentication is HTTP Basic with an EMPTY username and a locally generated password
  (`curl -u :<password>`). No OAuth, no OIDC, no scopes, no vendor-issued keys.
- phoenixd has a second, lower-privilege password (`http-password-limited-access`) that
  can read state and create invoices but CANNOT move funds. Prefer it for agent use.
- There is NO idempotency support on either API. A retried payment call can pay twice.
- phoenixd amounts are in SATOSHI. eclair amounts are in MILLISATOSHI by default. Two
  APIs from the same vendor, a factor of 1000 apart.
- Lightning payments are FINAL. There is no refund, void, chargeback or dispute
  primitive anywhere in either API.

## Machine-readable documentation (undocumented but live)

The phoenix.acinq.co site is a client-rendered SPA: every page path returns HTTP 403 to a
non-browser client. Its documentation content, however, is fetched at runtime as raw
markdown and those URLs return HTTP 200 with content-type text/markdown. These are the
most machine-readable ACINQ docs that exist:

- [phoenixd API reference (markdown)](https://phoenix.acinq.co/content/server/api.md): all 27 endpoints, parameters, curl examples, response bodies, webhook signature spec.
- [phoenixd get started (markdown)](https://phoenix.acinq.co/content/server/get-started.md): download, run, and first phoenix-cli calls.
- [phoenixd auto-liquidity + fees (markdown)](https://phoenix.acinq.co/content/server/liquidity.md): the fee model and the effective-feerate matrix.
- [phoenixd FAQ (markdown)](https://phoenix.acinq.co/content/server/faq.md): what phoenixd is, how it differs from eclair, self-custody and seed handling.
- [Phoenix terms of usage (markdown)](https://phoenix.acinq.co/content/terms.md)
- [Phoenix privacy policy (markdown)](https://phoenix.acinq.co/content/privacy.md)
- [ACINQ news index (JSON)](https://acinq.co/news/news.json): dated corporate announcements, newest entry 2019.

## APIs

- [phoenixd HTTP API](https://phoenix.acinq.co/server/api): self-custodial Lightning server daemon. Bolt11 invoices, Bolt12 offers, BIP-353 Lightning addresses, on-chain send and swap-in, payment history, channel management, invoice/offer decoding, liquidity fee quotes, LNURL pay/withdraw/auth. Plus a payments websocket and HMAC-SHA256 signed webhooks.
- [Eclair JSON API](https://acinq.github.io/eclair/): full routing-node control. Node info, peer connect/disconnect, channel open/close/force-close/splice/RBF, network graph queries, Bolt11 and Bolt12 payments, route finding, on-chain wallet, onion messaging, message signing, audit and balance reporting, payment-notification websocket.

## phoenixd endpoints

Receive: `POST /createinvoice`, `POST /createoffer`, `GET /getlnaddress`, `GET /getswapinaddress`.
Send: `POST /payinvoice`, `POST /payoffer`, `POST /paylnaddress`, `POST /sendtoaddress`, `POST /bumpfee`.
History: `GET /payments/incoming`, `GET /payments/incoming/{paymentHash}`, `GET /payments/outgoing`, `GET /payments/outgoing/{paymentId}`, `GET /payments/outgoingbyhash/{paymentHash}`, `POST /export`.
Node: `GET /getinfo`, `GET /getbalance`, `GET /listchannels`, `POST /closechannel`, `POST /decodeinvoice`, `POST /decodeoffer`, `GET /estimateliquidityfees`.
LNURL: `POST /lnurlpay`, `POST /lnurlwithdraw`, `POST /lnurlauth`.
Events: `WS /websocket`, plus outbound webhooks.
Deprecated: `GET /getoffer` — use `POST /createoffer`.

Fund-moving routes denied to the limited-access password: `payinvoice`, `payoffer`,
`paylnaddress`, `lnurlpay`, `lnurlauth`, `sendtoaddress`, `closechannel`, `export`.

## eclair methods

Node: `getinfo`. Connections: `connect`, `disconnect`, `peers`.
Channels: `open`, `rbfopen`, `cpfpbumpfees`, `splicein`, `spliceout`, `rbfsplice`, `close`, `forceclose`, `bumpforceclose`, `updaterelayfee`, `channels`, `channel`, `closedchannels`.
Network: `nodes`, `node`, `allchannels`, `allupdates`.
Payments: `createinvoice`, `deleteinvoice`, `parseinvoice`, `payinvoice`, `createoffer`, `listoffers`, `disableoffer`, `parseoffer`, `payoffer`, `sendtonode`, `sendtoroute`, `getsentinfo`, `getreceivedinfo`, `listreceivedpayments`, `getinvoice`, `listinvoices`, `listpendinginvoices`.
Routing: `findroute`, `findroutetonode`, `findroutebetweennodes`.
On-chain: `getnewaddress`, `sendonchain`, `onchainbalance`, `onchaintransactions`.
Messages: `sendonionmessage`, `signmessage`, `verifymessage`.
Misc: `audit`, `relaystats`, `usablebalances`, `channelbalances`, `globalbalance`, `getmasterxpub`, `getdescriptors`.
Events: `ws`.

Errors are uniform: `{"error": "<message>"}` with status 400, 401, 404 or 500.

## Pricing

There are no plans and no subscription. The software is Apache-2.0 and free; ACINQ charges
per transaction as the Lightning service provider:

- Sending via Lightning: 0.4% + 4 sat
- Receiving via Lightning with sufficient inbound liquidity: 0
- Receiving with insufficient liquidity, or requesting liquidity: 1% + mining fees
- Channel creation: 1000 sat
- On-chain send/receive: mining fees only

`GET /estimateliquidityfees?amountSat=` returns `{miningFeeSat, serviceFeeSat}` so cost can
be quoted before committing. The `fee credit` buffer is NON-REFUNDABLE and is not part of
the wallet balance.

- [Fees and auto-liquidity](https://phoenix.acinq.co/server/auto-liquidity)

## Testing

There is no hosted sandbox. Run the same binary against Bitcoin testnet with
`--chain=testnet` (phoenixd) or `eclair.chain=testnet` (eclair) — full protocol parity, no
mocking, worthless coins. Chain is discoverable at runtime from `POST /decodeinvoice`
(`chain` field) and from the invoice prefix (`lnbc` mainnet / `lntb` testnet) and address
prefix (`bc1` / `tb1`). There is no test/live key prefix, so only the chain flag separates
a test instance from production.

## Docs

- [phoenixd product page](https://phoenix.acinq.co/server)
- [phoenixd getting started](https://phoenix.acinq.co/server/get-started)
- [phoenixd FAQ](https://phoenix.acinq.co/server/faq)
- [eclair API notes](https://github.com/ACINQ/eclair/blob/master/docs/API.md)
- [eclair configuration](https://github.com/ACINQ/eclair/blob/master/docs/Configure.md)
- [eclair usage / eclair-cli](https://github.com/ACINQ/eclair/blob/master/docs/Usage.md)
- [Support](https://phoenix.acinq.co/support)
- [Terms of usage](https://phoenix.acinq.co/terms)
- [Privacy](https://phoenix.acinq.co/privacy)

## Source and packages

- [ACINQ GitHub organization](https://github.com/ACINQ)
- [ACINQ/phoenixd](https://github.com/ACINQ/phoenixd): the daemon. Releases carry the binary and `phoenix-cli`; current v0.9.0 (2026-07-13).
- [ACINQ/eclair](https://github.com/ACINQ/eclair): the Scala node; current v0.14.1 (2026-07-29).
- [ACINQ/phoenix](https://github.com/ACINQ/phoenix): the self-custodial mobile wallet.
- [ACINQ/lightning-kmp](https://github.com/ACINQ/lightning-kmp): Kotlin Multiplatform Lightning implementation; `fr.acinq.lightning:lightning-kmp-core:1.10.2`.
- [ACINQ/bitcoin-kmp](https://github.com/ACINQ/bitcoin-kmp): `fr.acinq.bitcoin:bitcoin-kmp:0.24.0`.
- [ACINQ/secp256k1-kmp](https://github.com/ACINQ/secp256k1-kmp): `fr.acinq.secp256k1:secp256k1-kmp:0.17.3`.
- [ACINQ/bitcoin-lib](https://github.com/ACINQ/bitcoin-lib): `fr.acinq:bitcoin-lib_2.13:0.40`.

All first-party libraries are on Maven Central under `fr.acinq*`. There is NO first-party
npm, PyPI, RubyGems, crates.io or NuGet package — packages matching "phoenixd" or "eclair"
on npm are third-party.

## Standards

Conformant: BOLT 1-12 Lightning specifications (eclair is a reference implementation and
ACINQ co-authored the specs), BOLT 11 invoices, BOLT 12 offers and onion messages, channel
splicing, BIP 353 Lightning addresses, LNURL LUD-04/pay/withdraw, BIP 39 seeds, BIP 173/350
bech32/bech32m, BIP 32 descriptors, RFC 7617 Basic auth, RFC 6455 WebSocket, HMAC-SHA256
webhook signing.

Not conformant: OpenAPI, AsyncAPI, RFC 9457 problem details, OAuth 2.0, OpenID Connect,
RFC 9116 security.txt, RFC 8594 Sunset, RFC 8615 well-known URIs, MCP, A2A.

## Security

- [Security policy](https://github.com/ACINQ/eclair/blob/master/SECURITY.md) — report to `security@acinq.fr`.
- PGP keys published on ACINQ's own domain: [padioupm](https://acinq.co/pgp/padioupm.asc), [drouinf](https://acinq.co/pgp/drouinf.asc), [tbast](https://acinq.co/pgp/tbast.asc).
- No bug bounty programme. No `/.well-known/security.txt`. No trust centre, and no SOC 2, ISO 27001 or PCI DSS certification is published.
- Domain posture (probed 2026-08-17): TLS 1.3, HSTS with a one-year max-age, DNSSEC enabled, SPF present, DMARC present at `p=none`, no CAA record.

## Company

- [Website](https://acinq.co/)
- [ACINQ node and vision](https://acinq.co/node)
- [Blog](https://acinq.co/blog)
- [Jobs](https://acinq.co/jobs)
- [X / Twitter @acinq_co](https://twitter.com/acinq_co)
- [X / Twitter @PhoenixWallet](https://twitter.com/PhoenixWallet)
- Contact: hello@acinq.co