nips/91.md

NIP-91: AND Operator in Filters

Enable AND within a single tag filter by using an & modifier in filters for indexable tags.

filters: {
  "kinds": [1],
  "&t": ["meme", "cat"],
  "#t": ["black", "white"]
}
// returns kind `1` events with `t` tags that have both "meme" and "cat" that have the tag "black" or "white"

Rules

• AND MUST take precedence over OR
• Tag values used in AND SHOULD NOT be used in standard OR tags [#]
• Any tag value used in AND SHOULD be ignored in OR