Ruby MCP reference

tool MCPv0.1.1

`tmux_capture`

tmux_capture()

tool [source]¶

Read exact-pane screen/history rows preserving LF. Defaults: 200 lines, 65536 bytes, zero history lines, track=false. Limits: 1000 lines/history, 262144 bytes. UTF-8 or base64; truncation is separate from unknown history continuity. Tracked process cursors require tmux>=3.3a and a native process identity backend: Linux peer pidfds with matching PID namespaces, or Darwin kqueue process observation. Continuation returns an exact state row splice, not a live-output journal. Refuses capture after-hooks.

MCP request method: tools/call Send tmux_capture as the tool name, with the arguments below.
Tool selection: Opt in with --enable-tool tmux_capture.

Arguments#

No named arguments.

Matches exactly one variant.

Variant 1 (object) #
- history_lines? (integer) #
  
  minimum
  0
  maximum
  1000
- max_bytes? (integer) #
  
  minimum
  1
  maximum
  262144
- max_lines? (integer) #
  
  minimum
  1
  maximum
  1000
- target (object) #
  
  Matches exactly one variant.
  - Variant 1 (object) #
    - generation (string) #
      
      minLength
      1
      maxLength
      128
    - id (string) #
      
      maxLength
      32
      pattern
      "^%[0-9]+$"
    - kind ("pane") #
    No other properties are accepted.
- track? (boolean) #
No other properties are accepted.
Variant 2 (object) #
- cursor (string) #
  
  maxLength
  32
  pattern
  "^[a-f0-9]{32}$"
- target (object) #
  
  Matches exactly one variant.
  - Variant 1 (object) #
    - generation (string) #
      
      minLength
      1
      maxLength
      128
    - id (string) #
      
      maxLength
      32
      pattern
      "^%[0-9]+$"
    - kind ("pane") #
    No other properties are accepted.
No other properties are accepted.

Result#

Returns object | object

Matches exactly one variant.

Variant 1 (object) #
- data (object | object) #
  
  Matches exactly one variant.
  - Variant 1 (object) #
    - bytes (integer) #
      
      minimum
      0
      maximum
      262144
    - capture_id (string) #
    - encoding ("utf-8" | "base64") #
    - history_continuity ("unknown") #
    - interval (object) #
      - clock ("monotonic_seconds") #
      - finished (number) #
      - started (number) #
      No other properties are accepted.
    - mode ("snapshot") #
    - next_cursor? (string) #
    - process_generation (string | null) #
    - row_count (integer) #
      
      minimum
      0
      maximum
      1000
    - rows (Array<string>) #
      
      maxItems
      1000
    - scope (object) #
      - history_lines (integer) #
        
        minimum
        0
        maximum
        1000
      - max_bytes (integer) #
        
        minimum
        1
        maximum
        262144
      - max_lines (integer) #
        
        minimum
        1
        maximum
        1000
      No other properties are accepted.
    - target (object) #
      
      Matches exactly one variant.
      - Variant 1 (object) #
        
        generation (string) #
        
        minLength
        1
        maxLength
        128
        
        id (string) #
        
        maxLength
        32
        pattern
        "^%[0-9]+$"
        
        kind ("pane") #
        
        No other properties are accepted.
    - truncated (boolean) #
    No other properties are accepted.
  - Variant 2 (object) #
    - base_capture_id (string) #
    - bytes (integer) #
      
      minimum
      0
      maximum
      262144
    - capture_id (string) #
    - encoding ("utf-8" | "base64") #
    - history_continuity ("unknown") #
    - interval (object) #
      - clock ("monotonic_seconds") #
      - finished (number) #
      - started (number) #
      No other properties are accepted.
    - mode ("delta") #
    - next_cursor (string) #
    - process_generation (string | null) #
    - reset (boolean) #
    - row_count (integer) #
      
      minimum
      0
      maximum
      1000
    - scope (object) #
      - history_lines (integer) #
        
        minimum
        0
        maximum
        1000
      - max_bytes (integer) #
        
        minimum
        1
        maximum
        262144
      - max_lines (integer) #
        
        minimum
        1
        maximum
        1000
      No other properties are accepted.
    - splice (object) #
      - delete (integer) #
        
        minimum
        0
      - rows (Array<string>) #
        
        maxItems
        1000
      - start (integer) #
        
        minimum
        0
      No other properties are accepted.
    - target (object) #
      
      Matches exactly one variant.
      - Variant 1 (object) #
        
        generation (string) #
        
        minLength
        1
        maxLength
        128
        
        id (string) #
        
        maxLength
        32
        pattern
        "^%[0-9]+$"
        
        kind ("pane") #
        
        No other properties are accepted.
    - truncated (boolean) #
    No other properties are accepted.
- ok (true) #
No other properties are accepted.
Variant 2 (object) #
- error (object) #
  - code (string) #
  - delivery ("not_sent" | "possibly_sent" | "observed") #
  - effects? (object) #
    - created (Array<object | object | object | object>) #
      
      maxItems
      3
      - Items (object | object | object | object) #
        
        Matches exactly one variant.
        
        Variant 1 (object) #
        
        generation (string) #
        
        minLength
        1
        maxLength
        128
        
        id (string) #
        
        maxLength
        32
        pattern
        "^\\$[0-9]+$"
        
        kind ("session") #
        
        No other properties are accepted.
        
        Variant 2 (object) #
        
        generation (string) #
        
        minLength
        1
        maxLength
        128
        
        id (string) #
        
        maxLength
        32
        pattern
        "^@[0-9]+$"
        
        kind ("window") #
        
        No other properties are accepted.
        
        Variant 3 (object) #
        
        generation (string) #
        
        minLength
        1
        maxLength
        128
        
        id (string) #
        
        maxLength
        32
        pattern
        "^%[0-9]+$"
        
        kind ("pane") #
        
        No other properties are accepted.
        
        Variant 4 (object) #
        
        generation (string) #
        
        minLength
        1
        maxLength
        128
        
        id (string) #
        
        maxLength
        32
        pattern
        "^@[0-9]+$"
        
        index (integer) #
        
        minimum
        0
        
        kind ("window_link") #
        
        session_id (string) #
        
        maxLength
        32
        pattern
        "^\\$[0-9]+$"
        
        No other properties are accepted.
    - state ("none" | "known" | "unknown") #
    No other properties are accepted.
  - message (string) #
  No other properties are accepted.
- ok (false) #
No other properties are accepted.

Annotations#

destructiveHint: false
idempotentHint: false
openWorldHint: false
readOnlyHint: false

Protocol data#

Use the complete advertised contract for validation and client integration.

Input schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "oneOf": [
    {
      "additionalProperties": false,
      "properties": {
        "history_lines": {
          "maximum": 1000,
          "minimum": 0,
          "type": "integer"
        },
        "max_bytes": {
          "maximum": 262144,
          "minimum": 1,
          "type": "integer"
        },
        "max_lines": {
          "maximum": 1000,
          "minimum": 1,
          "type": "integer"
        },
        "target": {
          "oneOf": [
            {
              "additionalProperties": false,
              "properties": {
                "generation": {
                  "maxLength": 128,
                  "minLength": 1,
                  "type": "string"
                },
                "id": {
                  "maxLength": 32,
                  "pattern": "^%[0-9]+$",
                  "type": "string"
                },
                "kind": {
                  "const": "pane"
                }
              },
              "required": [
                "generation",
                "kind",
                "id"
              ],
              "type": "object"
            }
          ]
        },
        "track": {
          "type": "boolean"
        }
      },
      "required": [
        "target"
      ],
      "type": "object"
    },
    {
      "additionalProperties": false,
      "properties": {
        "cursor": {
          "maxLength": 32,
          "pattern": "^[a-f0-9]{32}$",
          "type": "string"
        },
        "target": {
          "oneOf": [
            {
              "additionalProperties": false,
              "properties": {
                "generation": {
                  "maxLength": 128,
                  "minLength": 1,
                  "type": "string"
                },
                "id": {
                  "maxLength": 32,
                  "pattern": "^%[0-9]+$",
                  "type": "string"
                },
                "kind": {
                  "const": "pane"
                }
              },
              "required": [
                "generation",
                "kind",
                "id"
              ],
              "type": "object"
            }
          ]
        }
      },
      "required": [
        "target",
        "cursor"
      ],
      "type": "object"
    }
  ],
  "type": "object"
}

Output schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "oneOf": [
    {
      "additionalProperties": false,
      "properties": {
        "data": {
          "oneOf": [
            {
              "additionalProperties": false,
              "properties": {
                "bytes": {
                  "maximum": 262144,
                  "minimum": 0,
                  "type": "integer"
                },
                "capture_id": {
                  "type": "string"
                },
                "encoding": {
                  "enum": [
                    "utf-8",
                    "base64"
                  ]
                },
                "history_continuity": {
                  "const": "unknown"
                },
                "interval": {
                  "additionalProperties": false,
                  "properties": {
                    "clock": {
                      "const": "monotonic_seconds"
                    },
                    "finished": {
                      "type": "number"
                    },
                    "started": {
                      "type": "number"
                    }
                  },
                  "required": [
                    "clock",
                    "started",
                    "finished"
                  ],
                  "type": "object"
                },
                "mode": {
                  "const": "snapshot"
                },
                "next_cursor": {
                  "type": "string"
                },
                "process_generation": {
                  "type": [
                    "string",
                    "null"
                  ]
                },
                "row_count": {
                  "maximum": 1000,
                  "minimum": 0,
                  "type": "integer"
                },
                "rows": {
                  "items": {
                    "type": "string"
                  },
                  "maxItems": 1000,
                  "type": "array"
                },
                "scope": {
                  "additionalProperties": false,
                  "properties": {
                    "history_lines": {
                      "maximum": 1000,
                      "minimum": 0,
                      "type": "integer"
                    },
                    "max_bytes": {
                      "maximum": 262144,
                      "minimum": 1,
                      "type": "integer"
                    },
                    "max_lines": {
                      "maximum": 1000,
                      "minimum": 1,
                      "type": "integer"
                    }
                  },
                  "required": [
                    "max_lines",
                    "max_bytes",
                    "history_lines"
                  ],
                  "type": "object"
                },
                "target": {
                  "oneOf": [
                    {
                      "additionalProperties": false,
                      "properties": {
                        "generation": {
                          "maxLength": 128,
                          "minLength": 1,
                          "type": "string"
                        },
                        "id": {
                          "maxLength": 32,
                          "pattern": "^%[0-9]+$",
                          "type": "string"
                        },
                        "kind": {
                          "const": "pane"
                        }
                      },
                      "required": [
                        "generation",
                        "kind",
                        "id"
                      ],
                      "type": "object"
                    }
                  ]
                },
                "truncated": {
                  "type": "boolean"
                }
              },
              "required": [
                "target",
                "capture_id",
                "process_generation",
                "encoding",
                "row_count",
                "bytes",
                "truncated",
                "history_continuity",
                "interval",
                "scope",
                "mode",
                "rows"
              ],
              "type": "object"
            },
            {
              "additionalProperties": false,
              "properties": {
                "base_capture_id": {
                  "type": "string"
                },
                "bytes": {
                  "maximum": 262144,
                  "minimum": 0,
                  "type": "integer"
                },
                "capture_id": {
                  "type": "string"
                },
                "encoding": {
                  "enum": [
                    "utf-8",
                    "base64"
                  ]
                },
                "history_continuity": {
                  "const": "unknown"
                },
                "interval": {
                  "additionalProperties": false,
                  "properties": {
                    "clock": {
                      "const": "monotonic_seconds"
                    },
                    "finished": {
                      "type": "number"
                    },
                    "started": {
                      "type": "number"
                    }
                  },
                  "required": [
                    "clock",
                    "started",
                    "finished"
                  ],
                  "type": "object"
                },
                "mode": {
                  "const": "delta"
                },
                "next_cursor": {
                  "type": "string"
                },
                "process_generation": {
                  "type": [
                    "string",
                    "null"
                  ]
                },
                "reset": {
                  "type": "boolean"
                },
                "row_count": {
                  "maximum": 1000,
                  "minimum": 0,
                  "type": "integer"
                },
                "scope": {
                  "additionalProperties": false,
                  "properties": {
                    "history_lines": {
                      "maximum": 1000,
                      "minimum": 0,
                      "type": "integer"
                    },
                    "max_bytes": {
                      "maximum": 262144,
                      "minimum": 1,
                      "type": "integer"
                    },
                    "max_lines": {
                      "maximum": 1000,
                      "minimum": 1,
                      "type": "integer"
                    }
                  },
                  "required": [
                    "max_lines",
                    "max_bytes",
                    "history_lines"
                  ],
                  "type": "object"
                },
                "splice": {
                  "additionalProperties": false,
                  "properties": {
                    "delete": {
                      "minimum": 0,
                      "type": "integer"
                    },
                    "rows": {
                      "items": {
                        "type": "string"
                      },
                      "maxItems": 1000,
                      "type": "array"
                    },
                    "start": {
                      "minimum": 0,
                      "type": "integer"
                    }
                  },
                  "required": [
                    "start",
                    "delete",
                    "rows"
                  ],
                  "type": "object"
                },
                "target": {
                  "oneOf": [
                    {
                      "additionalProperties": false,
                      "properties": {
                        "generation": {
                          "maxLength": 128,
                          "minLength": 1,
                          "type": "string"
                        },
                        "id": {
                          "maxLength": 32,
                          "pattern": "^%[0-9]+$",
                          "type": "string"
                        },
                        "kind": {
                          "const": "pane"
                        }
                      },
                      "required": [
                        "generation",
                        "kind",
                        "id"
                      ],
                      "type": "object"
                    }
                  ]
                },
                "truncated": {
                  "type": "boolean"
                }
              },
              "required": [
                "target",
                "capture_id",
                "process_generation",
                "encoding",
                "row_count",
                "bytes",
                "truncated",
                "history_continuity",
                "interval",
                "scope",
                "mode",
                "base_capture_id",
                "reset",
                "splice",
                "next_cursor"
              ],
              "type": "object"
            }
          ]
        },
        "ok": {
          "const": true
        }
      },
      "required": [
        "ok",
        "data"
      ],
      "type": "object"
    },
    {
      "additionalProperties": false,
      "properties": {
        "error": {
          "additionalProperties": false,
          "properties": {
            "code": {
              "type": "string"
            },
            "delivery": {
              "enum": [
                "not_sent",
                "possibly_sent",
                "observed"
              ]
            },
            "effects": {
              "additionalProperties": false,
              "properties": {
                "created": {
                  "items": {
                    "oneOf": [
                      {
                        "additionalProperties": false,
                        "properties": {
                          "generation": {
                            "maxLength": 128,
                            "minLength": 1,
                            "type": "string"
                          },
                          "id": {
                            "maxLength": 32,
                            "pattern": "^\\$[0-9]+$",
                            "type": "string"
                          },
                          "kind": {
                            "const": "session"
                          }
                        },
                        "required": [
                          "generation",
                          "kind",
                          "id"
                        ],
                        "type": "object"
                      },
                      {
                        "additionalProperties": false,
                        "properties": {
                          "generation": {
                            "maxLength": 128,
                            "minLength": 1,
                            "type": "string"
                          },
                          "id": {
                            "maxLength": 32,
                            "pattern": "^@[0-9]+$",
                            "type": "string"
                          },
                          "kind": {
                            "const": "window"
                          }
                        },
                        "required": [
                          "generation",
                          "kind",
                          "id"
                        ],
                        "type": "object"
                      },
                      {
                        "additionalProperties": false,
                        "properties": {
                          "generation": {
                            "maxLength": 128,
                            "minLength": 1,
                            "type": "string"
                          },
                          "id": {
                            "maxLength": 32,
                            "pattern": "^%[0-9]+$",
                            "type": "string"
                          },
                          "kind": {
                            "const": "pane"
                          }
                        },
                        "required": [
                          "generation",
                          "kind",
                          "id"
                        ],
                        "type": "object"
                      },
                      {
                        "additionalProperties": false,
                        "properties": {
                          "generation": {
                            "maxLength": 128,
                            "minLength": 1,
                            "type": "string"
                          },
                          "id": {
                            "maxLength": 32,
                            "pattern": "^@[0-9]+$",
                            "type": "string"
                          },
                          "index": {
                            "minimum": 0,
                            "type": "integer"
                          },
                          "kind": {
                            "const": "window_link"
                          },
                          "session_id": {
                            "maxLength": 32,
                            "pattern": "^\\$[0-9]+$",
                            "type": "string"
                          }
                        },
                        "required": [
                          "generation",
                          "kind",
                          "id",
                          "session_id",
                          "index"
                        ],
                        "type": "object"
                      }
                    ]
                  },
                  "maxItems": 3,
                  "type": "array"
                },
                "state": {
                  "enum": [
                    "none",
                    "known",
                    "unknown"
                  ]
                }
              },
              "required": [
                "state",
                "created"
              ],
              "type": "object"
            },
            "message": {
              "type": "string"
            }
          },
          "required": [
            "code",
            "message",
            "delivery"
          ],
          "type": "object"
        },
        "ok": {
          "const": false
        }
      },
      "required": [
        "ok",
        "error"
      ],
      "type": "object"
    }
  ],
  "type": "object"
}

Scripting & web

Compiled & native

JVM

.NET

BEAM

tmux

`tmux_capture`

Arguments#

Result#

Annotations#

Protocol data#