Module lightning::offers::offer

Data structures and encoding for offer messages.

An Offer represents an “offer to be paid.” It is typically constructed by a merchant and published as a QR code to be scanned by a customer. The customer uses the offer to request an invoice from the merchant to be paid.

Example

extern crate bitcoin;
extern crate core;
extern crate lightning;

use core::convert::TryFrom;
use core::num::NonZeroU64;
use core::time::Duration;

use bitcoin::secp256k1::{KeyPair, PublicKey, Secp256k1, SecretKey};
use lightning::offers::offer::{Offer, OfferBuilder, Quantity};
use lightning::offers::parse::Bolt12ParseError;
use lightning::util::ser::{Readable, Writeable};

let secp_ctx = Secp256k1::new();
let keys = KeyPair::from_secret_key(&secp_ctx, &SecretKey::from_slice(&[42; 32]).unwrap());
let pubkey = PublicKey::from(keys);

let expiration = SystemTime::now() + Duration::from_secs(24 * 60 * 60);
let offer = OfferBuilder::new("coffee, large".to_string(), pubkey)
    .amount_msats(20_000)
    .supported_quantity(Quantity::Unbounded)
    .absolute_expiry(expiration.duration_since(SystemTime::UNIX_EPOCH).unwrap())
    .issuer("Foo Bar".to_string())
    .path(create_blinded_path())
    .path(create_another_blinded_path())
    .build()?;

// Encode as a bech32 string for use in a QR code.
let encoded_offer = offer.to_string();

// Parse from a bech32 string after scanning from a QR code.
let offer = encoded_offer.parse::<Offer>()?;

// Encode offer as raw bytes.
let mut bytes = Vec::new();
offer.write(&mut bytes).unwrap();

// Decode raw bytes into an offer.
let offer = Offer::try_from(bytes)?;

Note

If constructing an Offer for use with a ChannelManager, use ChannelManager::create_offer_builder instead of OfferBuilder::new.

Structs

• DerivedMetadata
  Offer::metadata will be derived.
• ExplicitMetadata
  Offer::metadata may be explicitly set or left empty.
• Offer
  An Offer is a potentially long-lived proposal for payment of a good or service.
• OfferBuilder
  Builds an Offer for the “offer to be paid” flow.

Enums

• Amount
  The minimum amount required for an item in an Offer, denominated in either bitcoin or another currency.
• Quantity
  Quantity of items supported by an Offer.

Traits

• MetadataStrategy
  Indicates how Offer::metadata may be set.

Type Aliases

• CurrencyCode
  An ISO 4712 three-letter currency code (e.g., USD).