NIPs nostr improvement proposals

NIP-19 - bech32-encoded entities

Table of Contents

bech32-encoded entities

draft optional

This NIP standardizes bech32-formatted strings that can be used to display keys, ids and other information in clients. These formats are not meant to be used anywhere in the core protocol, they are only meant for displaying to users, copy-pasting, sharing, rendering QR codes and inputting data.

It is recommended that ids and keys are stored in either hex or binary format, since these formats are closer to what must actually be used the core protocol.

Bare keys and ids

To prevent confusion and mixing between private keys, public keys and event ids, which are all 32 byte strings. bech32-(not-m) encoding with different prefixes can be used for each of these entities.

These are the possible bech32 prefixes:

Example: the hex public key 3bf0c63fcb93463407af97a5e5ee64fa883d107ef9e558472c4eb9aaaefa459d translates to npub180cvv07tjdrrgpa0j7j7tmnyl2yr6yr7l8j4s3evf6u64th6gkwsyjh6w6.

The bech32 encodings of keys and ids are not meant to be used inside the standard NIP-01 event formats or inside the filters, they're meant for human-friendlier display and input only. Clients should still accept keys in both hex and npub format for now, and convert internally.

Shareable identifiers with extra metadata

When sharing a profile or an event, an app may decide to include relay information and other metadata such that other apps can locate and display these entities more easily.

For these events, the contents are a binary-encoded list of TLV (type-length-value), with T and L being 1 byte each (uint8, i.e. a number in the range of 0-255), and V being a sequence of bytes of the size indicated by L.

These are the possible bech32 prefixes with TLV:

These possible standardized TLV types are indicated here: