Standard Tags Reference
Nostr events carry structured data in their tags array. Each tag is a JSON array where the first element is the tag name and subsequent elements are tag-specific values.
The table below lists all standardised tags defined across NIPs.
| Tag Name | Value Description | Defined In |
|---|---|---|
| - | — | NIP-70 |
| a | coordinates to an event | NIP-01 |
| A | root address | NIP-22 |
| alt | summary | NIP-31 |
| amount | millisatoshis, stringified | NIP-57 |
| bolt11 | bolt11 invoice | NIP-57 |
| branch-name | branch name suggestion | NIP-34 |
| c | commit id | NIP-34 |
| challenge | challenge string | NIP-42 |
| client | name, address | NIP-89 |
| clone | git clone URL | NIP-34 |
| content-warning | reason | NIP-36 |
| d | identifier | NIP-01 |
| D | day | NIP-52 |
| delegation | pubkey, conditions, delegation token | NIP-26 |
| dep | Required dependency | NIP-C0 |
| description | description | NIP-34, NIP-57, NIP-58, NIP-C0 |
| e | event id (hex) | NIP-01, NIP-10 |
| E | root event id | NIP-22 |
| emoji | shortcode, image URL | NIP-30 |
| encrypted | — | NIP-90 |
| expiration | unix timestamp (string) | NIP-40 |
| extension | File extension | NIP-C0 |
| f | currency code | NIP-69 |
| file | full path (string) | NIP-35 |
| g | geohash | NIP-52 |
| goal | event id (hex) | NIP-75 |
| h | group id | NIP-29 |
| HEAD | ref: refs/heads/<branch-name> | NIP-34 |
| i | external identity | NIP-35, NIP-39, NIP-73 |
| I | root external identity | NIP-22 |
| image | image URL | NIP-23, NIP-52, NIP-58 |
| imeta | inline metadata | NIP-92 |
| k | kind | NIP-18, NIP-25, NIP-72, NIP-73 |
| K | root scope | NIP-22 |
| l | label, label namespace, language name | NIP-32, NIP-C0 |
| L | label namespace | NIP-32 |
| license | License of the shared content | NIP-C0 |
| lnurl | bech32 encoded lnurl | NIP-57 |
| location | location string | NIP-52, NIP-99 |
| m | MIME type | NIP-94 |
| merge-base | commit id | NIP-34 |
| name | name | NIP-34, NIP-58, NIP-72, NIP-C0 |
| nonce | random | NIP-13 |
| p | pubkey (hex) | NIP-01, NIP-02, NIP-22 |
| P | pubkey (hex) | NIP-22, NIP-57 |
| preimage | hash of bolt11 invoice | NIP-57 |
| price | price | NIP-99 |
| proxy | external ID | NIP-48 |
| published_at | unix timestamp (string) | NIP-23, NIP-B0 |
| q | event id (hex) | NIP-18 |
| r | a reference (URL, etc) | NIP-24, NIP-25 |
| r | relay url | NIP-65 |
| relay | relay url | NIP-42, NIP-17 |
| relays | relay list | NIP-57 |
| repo | Reference to the origin repository | NIP-C0 |
| runtime | Runtime or environment specification | NIP-C0 |
| s | status | NIP-69 |
| server | file storage server url | NIP-96 |
| sound | shortcode, sound url, image url | NIP-51 |
| subject | subject | NIP-14, NIP-17, NIP-34 |
| summary | summary | NIP-23, NIP-52 |
| t | hashtag | NIP-24, NIP-34, NIP-35 |
| thumb | badge thumbnail | NIP-58 |
| title | title | NIP-23, NIP-B0 |
| tracker | torrent tracker URL | NIP-35 |
| u | url | NIP-61, NIP-98 |
| web | webpage URL | NIP-34 |
| x | hash | NIP-35, NIP-56 |
| y | platform | NIP-69 |
| z | order number | NIP-69 |
| zap | pubkey (hex), relay URL | NIP-57 |