Kind 64: Chess (PGN)

Overview

Kind 64 events represent chess games in Portable Game Notation (PGN) format. PGN is a standard format for recording chess games that can be read by humans and is supported by most chess software. This kind allows Nostr to be used for recording, sharing, and replaying chess games between users.

Specification

Property	Value
Kind Number	64
Event Range	Regular
Defined in	NIP-64

Content Format

The content field of a kind 64 event contains a string representing a PGN-database. This can range from a very simple notation for games in progress to a full game record with metadata tags, move sequences, commentary, and results.

Schema

// Minimal example
"content": "1. e4 *"

// Full example with metadata tags, moves, and annotations
"content": "[Event \"F/S Return Match\"]\n[Site \"Belgrade, Serbia JUG\"]\n[Date \"1992.11.04\"]\n[Round \"29\"]\n[White \"Fischer, Robert J.\"]\n[Black \"Spassky, Boris V.\"]\n[Result \"1/2-1/2\"]\n\n1. e4 e5 2. Nf3 Nc6 3. Bb5 {This opening is called the Ruy Lopez.} 3... a6\n4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Nb8 10. d4 Nbd7\n11. c4 c6 12. cxb5 axb5 13. Nc3 Bb7 14. Bg5 b4 15. Nb1 h6 16. Bh4 c5 17. dxe5\nNxe4 18. Bxe7 Qxe7 19. exd6 Qf6 20. Nbd2 Nxd6 21. Nc4 Nxc4 22. Bxc4 Nb6\n23. Ne5 Rae8 24. Bxf7+ Rxf7 25. Nxf7 Rxe1+ 26. Qxe1 Kxf7 27. Qe3 Qg5 28. Qxg5\nhxg5 29. b3 Ke6 30. a3 Kd6 31. axb4 cxb4 32. Ra5 Nd5 33. f3 Bc8 34. Kf2 Bf5\n35. Ra7 g6 36. Ra6+ Kc5 37. Ke1 Nf4 38. g3 Nxh3 39. Kd2 Kb5 40. Rd6 Kc5 41. Ra6\nNf2 42. g4 Bd3 43. Re6 1/2-1/2"

Tags

Tag Name	Description	Format	Required
alt	Human-readable description for non-supporting clients	["alt", "Description of the chess game"]	No
Additional tags can be used for categorization or to provide context

Client Behavior

Clients should:

1. Display the chess game visually as a board representation when possible
2. Allow users to step through moves and replay the game
3. Publish PGN notes in "export format" (strict mode, created by machines)
4. Accept incoming notes in "import format" (lax mode, created by humans)
5. Validate that the PGN formatting is valid and chess moves comply with chess rules
6. Consider including the alt tag to provide a description for clients that don't support chess visualization

Relay Behavior

Relays may:

1. Optionally validate PGN contents and reject invalid notes
2. Otherwise handle these events like other regular events

Use Cases

• Recording casual or competitive chess games between Nostr users
• Sharing famous or interesting chess games
• Creating chess puzzles or challenges
• Building chess communities within the Nostr ecosystem
• Teaching chess strategies and openings

Example

{
  "id": "4376c65d2f232afbe9b882a35baa4f6fe8667c4e684749af565f981833ed6a65",
  "pubkey": "79dff8f82963424e0bb02708a22e44b4980893e3a4be0fa3cb60a43b946764e3",
  "created_at": 1671217411,
  "kind": 64,
  "tags": [
    ["alt", "Fischer vs. Spassky in Belgrade on 1992-11-04 (F/S Return Match, Round 29)"]
  ],
  "content": "[Event \"F/S Return Match\"]\n[Site \"Belgrade, Serbia JUG\"]\n[Date \"1992.11.04\"]\n[Round \"29\"]\n[White \"Fischer, Robert J.\"]\n[Black \"Spassky, Boris V.\"]\n[Result \"1/2-1/2\"]\n\n1. e4 e5 2. Nf3 Nc6 3. Bb5 {This opening is called the Ruy Lopez.} 3... a6\n4. Ba4 Nf6 5. O-O Be7 6. Re1 b5 7. Bb3 d6 8. c3 O-O 9. h3 Nb8 10. d4 Nbd7\n11. c4 c6 12. cxb5 axb5 13. Nc3 Bb7 14. Bg5 b4 15. Nb1 h6 16. Bh4 c5 17. dxe5\nNxe4 18. Bxe7 Qxe7 19. exd6 Qf6 20. Nbd2 Nxd6 21. Nc4 Nxc4 22. Bxc4 Nb6\n23. Ne5 Rae8 24. Bxf7+ Rxf7 25. Nxf7 Rxe1+ 26. Qxe1 Kxf7 27. Qe3 Qg5 28. Qxg5\nhxg5 29. b3 Ke6 30. a3 Kd6 31. axb4 cxb4 32. Ra5 Nd5 33. f3 Bc8 34. Kf2 Bf5\n35. Ra7 g6 36. Ra6+ Kc5 37. Ke1 Nf4 38. g3 Nxh3 39. Kd2 Kb5 40. Rd6 Kc5 41. Ra6\nNf2 42. g4 Bd3 43. Re6 1/2-1/2",
  "sig": "908a15e46fb4d8675bab026fc230a0e3542bfade63da02d542fb78b2a8513fcd0092619a2c8c1221e581946e0191f2af505dfdf8657a414dbca329186f009262"
}

Minimal example:

{
  "id": "fe8b1c9a37218cf5ce604a8dce596c9c3ae0c650df2336f3c60c78e61a7b2031",
  "pubkey": "f7234bd4c1394dda46d09f35bd384dd30cc552ad5541990f98844fb06676e9ca",
  "created_at": 1671217500,
  "kind": 64,
  "tags": [
    ["alt", "Game in progress - White has moved e4"]
  ],
  "content": "1. e4 *",
  "sig": "a76f39224cebd44cf04eeebe01d5ab2e8f7a3e5e56c83cadd252e7bc5e2e34fd7ad7148cf7a2c7620d9490ccf2e1bac521995725f2e1f543159b8eb98bfdd405"
}

References

• NIP-64: Chess (PGN)
• PGN Specification
• NIP-31: Alt Tag (for context on the alt tag)

Related Kinds

This kind doesn't have direct relationships with other kinds, but could be referenced in:

• Kind 1: Short Text Note - For discussing chess games
• Kind 6: Repost - For resharing interesting chess games
• Kind 7: Reaction - For reacting to chess games

Notes

• PGN has two formats: "export format" (strict, machine-generated) and "import format" (lax, human-created). Clients should publish in export format but accept both.
• The standard PGN Seven Tag Roster includes: Event, Site, Date, Round, White, Black, and Result.
• The * symbol at the end of a move sequence indicates a game in progress or with an unknown result.
• PGN supports annotations in curly braces {like this} for commentary on specific moves.
• Moves can include annotations like ! (good move), ? (bad move), etc.