MahjongHandbook — American NMJL, MCR & Riichi Mahjong Scoring Rules Engine
Working · 95 ms Security Acom.mahjonghandbook/mcpv1.0.2 Domain verified
Query American NMJL, Chinese Official MCR (81 Fan) & Japanese Riichi Mahjong scoring rules.
Maintained bymahjonghandbook.com(verified)Also a maintainer?
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Call this server's tools from your browser. Nothing to install.
https://mahjonghandbook.com/api/mcp
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Tool list from our last check. Connect live to refresh it.
check_nmjl_joker_legality Read-only
Validate whether an American Mahjong Joker tile can legally substitute inside a specific meld size (1 to 6 tiles) and retrieve exposed Joker live-turn swap rules.
Exact number of tiles in the target meld group (1, 2, 3, 4, 5, or 6)
Install
Pick your client. Values in capitals, like YOUR_TOKEN, are yours to fill in.
Run in a terminal
claude mcp add --transport http mcp https://mahjonghandbook.com/api/mcp
Tools (4)
Tool list last changed Nov 10, 2026.
check_nmjl_joker_legalityValidate whether an American Mahjong Joker tile can legally substitute inside a specific meld size (1 to 6 tiles) and retrieve exposed Joker live-turn swap rules.
read-only
check_nmjl_joker_legality
Validate whether an American Mahjong Joker tile can legally substitute inside a specific meld size (1 to 6 tiles) and retrieve exposed Joker live-turn swap rules.
| Argument | Type | Description |
|---|---|---|
| groupSize* | integer | Exact number of tiles in the target meld group (1, 2, 3, 4, 5, or 6) |
Input schema (JSON)
{
"type": "object",
"required": [
"groupSize"
],
"properties": {
"groupSize": {
"type": "integer",
"description": "Exact number of tiles in the target meld group (1, 2, 3, 4, 5, or 6)"
}
}
}check_riichi_furiten_and_yakuEvaluate Japanese Riichi Mahjong discard/temporary Furiten Ron restrictions and verify whether a hand satisfies the mandatory 1-Yaku win condition independent of Dora.
read-only
check_riichi_furiten_and_yaku
Evaluate Japanese Riichi Mahjong discard/temporary Furiten Ron restrictions and verify whether a hand satisfies the mandatory 1-Yaku win condition independent of Dora.
| Argument | Type | Description |
|---|---|---|
| scenario* | string | Japanese Riichi Mahjong win-validation scenario |
Input schema (JSON)
{
"type": "object",
"required": [
"scenario"
],
"properties": {
"scenario": {
"enum": [
"discard-furiten",
"temporary-furiten",
"dora-only-no-yaku",
"open-tanyao"
],
"type": "string",
"description": "Japanese Riichi Mahjong win-validation scenario"
}
}
}lookup_american_charleston_sequenceRetrieve exact pre-game tile passing directions (Right, Across, Left), blind pass rules, and Courtesy Pass negotiation steps prior to the first discard in American Mahjong.
read-only
lookup_american_charleston_sequence
Retrieve exact pre-game tile passing directions (Right, Across, Left), blind pass rules, and Courtesy Pass negotiation steps prior to the first discard in American Mahjong.
| Argument | Type | Description |
|---|---|---|
| phase* | string | Specific pre-game Charleston passing stage |
Input schema (JSON)
{
"type": "object",
"required": [
"phase"
],
"properties": {
"phase": {
"enum": [
"first-charleston",
"second-charleston",
"courtesy-pass",
"full-sequence"
],
"type": "string",
"description": "Specific pre-game Charleston passing stage"
}
}
}lookup_mahjong_scoring_rulesCompare high-level regional ruleset structures (tile deck size 136 vs 144 vs 152, hand length, and minimum Fan/point entry thresholds) across American, Chinese MCR, Japanese Riichi, and Hong Kong Mahjong. Do not use for Charleston passing steps, NMJL Joker meld legality, or Riichi Furiten checks.
read-only
lookup_mahjong_scoring_rules
Compare high-level regional ruleset structures (tile deck size 136 vs 144 vs 152, hand length, and minimum Fan/point entry thresholds) across American, Chinese MCR, Japanese Riichi, and Hong Kong Mahjong. Do not use for Charleston passing steps, NMJL Joker meld legality, or Riichi Furiten checks.
| Argument | Type | Description |
|---|---|---|
| variant* | string | Regional Mahjong ruleset variant to inspect |
Input schema (JSON)
{
"type": "object",
"required": [
"variant"
],
"properties": {
"variant": {
"enum": [
"american-nmjl",
"chinese-mcr",
"japanese-riichi",
"hong-kong"
],
"type": "string",
"description": "Regional Mahjong ruleset variant to inspect"
}
}
}Security checkA100/100
We read every tool's name, description and inputs the way the model will, looking for instructions hidden from you. A clean result means no warning signs, not a guarantee. Scanned Nov 10, 2026.
- Hidden or reordered text
- Overriding the model's instructions
- Hiding actions from the user
- Reading keys or credentials
- Fake system tags
- Steering other servers' tools
- Pulling in the conversation
- Smuggling parameters
- Demanding to be used for everything
- Steering away from web search
- Download-and-run commands
- Encoded blobs
- Invisible characters
- Credentials as tool arguments
- Very long descriptions
- Read and write hints
Tool changes
What changed in this server's tools since we started watching, newest first. Each change is scanned again.
check_riichi_furiten_and_yakuaddedNov 10, 2026
Evaluate Japanese Riichi Mahjong discard/temporary Furiten Ron restrictions and verify whether a hand satisfies the mandatory 1-Yaku win condition independent of Dora.
check_nmjl_joker_legalityaddedNov 10, 2026
Validate whether an American Mahjong Joker tile can legally substitute inside a specific meld size (1 to 6 tiles) and retrieve exposed Joker live-turn swap rules.
lookup_american_charleston_sequenceaddedNov 10, 2026
Retrieve exact pre-game tile passing directions (Right, Across, Left), blind pass rules, and Courtesy Pass negotiation steps prior to the first discard in American Mahjong.
lookup_mahjong_scoring_ruleschanged (title, description, inputs, hints)Nov 10, 2026
LookCompareuphigh-levelofficialregionalrules,rulesetminimumstructureswinning(tilerequirements,deckJoker/Dorasizeusage,136andvsFan/Han144scoringvspatterns152,acrosshandAmericanlength,Mahjongand(NMJL),minimum Fan/point entry thresholds) across American, ChineseOfficialMCR,(MCR),Japanese Riichi, andJapaneseHongRiichiKong Mahjong. Do not use for Charleston passing steps, NMJL Joker meld legality, or Riichi Furiten checks.{ "type": "object", "required": [ "variant" ], "properties": { "variant": { "enum": [ "american-nmjl", "chinese-mcr", "japanese-riichi", "hong-kong" ], "type": "string", "description": "Mahjong ruleset variant (default: american-nmjl)" } } }{ "type": "object", "required": [ "variant" ], "properties": { "variant": { "enum": [ "american-nmjl", "chinese-mcr", "japanese-riichi", "hong-kong" ], "type": "string", "description": "Regional Mahjong ruleset variant to inspect" } } }