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cnvs.app

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Real-time collaborative whiteboard — AI agents and humans edit the same board live over MCP.

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add_image Destructive

Place a raster or SVG image on the board at (x, y) with explicit width/height in board pixels. `data_url` MUST be a `data:image/(png|jpeg|gif|webp|svg+xml);base64,...` string ≤ ~900 kB; hosted URLs are not accepted. Strongly recommended: also pass a tiny `thumb_data_url` (≤8 kB JPEG/PNG/WebP, ~64 px on the long edge) — it is embedded into the SVG preview so OTHER AI viewers (and you, on later `get_preview` calls) can actually see the image instead of a placeholder box.

xnumber, required

ynumber, required

widthnumber, required

heightnumber, required

board_idstring, required

data_urlstring, required

idstring

authorstring

access_keystring

8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

thumb_data_urlstring

The server marks this tool as destructive. Running it may delete or overwrite data on the server or in any account you connected with your headers.

I understand, run it anyway

cnvs.app MCP server | mcptry

cnvs.app

Working · 1.6 s

app.cnvs/whiteboardv1.0.2 Domain verified

Real-time collaborative whiteboard — AI agents and humans edit the same board live over MCP.

Productivity

Source Website Registry entry

Maintain this server? Claim it

Try it

Call this server's tools from your browser. Nothing to install.

https://cnvs.app/mcp

Requests go through mcptry because browsers can't call most MCP servers directly. Header values are sent to the server for that request only and are never stored or logged.

Tool list from our last check. Connect live to refresh it.

add_image Destructive

xnumber, required

ynumber, required

widthnumber, required

heightnumber, required

board_idstring, required

data_urlstring, required

idstring

authorstring

access_keystring

thumb_data_urlstring

The server marks this tool as destructive. Running it may delete or overwrite data on the server or in any account you connected with your headers.

I understand, run it anyway

Tools (25)

add_image

destructive

Argument	Type	Description
x*	number
y*	number
id	string
width*	number
author	string
height*	number
board_id*	string
data_url*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.
thumb_data_url	string

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "x",
    "y",
    "width",
    "height",
    "data_url"
  ],
  "properties": {
    "x": {
      "type": "number"
    },
    "y": {
      "type": "number"
    },
    "id": {
      "type": "string"
    },
    "width": {
      "type": "number"
    },
    "author": {
      "type": "string"
    },
    "height": {
      "type": "number"
    },
    "board_id": {
      "type": "string"
    },
    "data_url": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    },
    "thumb_data_url": {
      "type": "string"
    }
  }
}

add_link

Drop a URL capsule onto the board — rendered as a clickable pill showing the hostname. Use this instead of `add_text` when the node is just a link; the capsule styling signals clickability to humans. Same coordinate rules as `add_text` (+x right, +y down).

Argument	Type	Description
x*	number
y*	number
url*	string
author	string
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "x",
    "y",
    "url"
  ],
  "properties": {
    "x": {
      "type": "number"
    },
    "y": {
      "type": "number"
    },
    "url": {
      "type": "string"
    },
    "author": {
      "type": "string"
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

add_text

Create a NEW text node, or update an existing one (pass the same `id` to overwrite content/position in place — preferred over creating a duplicate). Supports cnvs markup (Markdown-ish) and Mermaid diagrams in the content. When using Mermaid, the ENTIRE content of this text node must be a single Mermaid diagram (one ```mermaid fenced block and nothing else — no heading, no prose before or after). If you need prose + a diagram, create two separate text nodes. `postit: true` renders as a yellow sticky; `diagram: true` renders as a framed box (2px border in the text colour, centred text) — the two are mutually exclusive. Coordinates are in board-world pixels, +x right, +y DOWN; pick a spot that does not overlap existing items (check `get_preview` first). Default width auto-fits content up to ~320 px; pass `width` for explicit wrapping (160–4096). Keep content under 100 000 chars.

destructive

Argument	Type	Description
x*	number
y*	number
id	string	Optional stable id; generated when omitted.
color	string	Named ink only (no hex). Accepted (case-insensitive): 'auto'/''/'black'/omitted for theme-aware ink, or 'red', 'blue', 'green', 'orange', 'yellow', 'pink', 'purple', 'maroon', 'brown', 'gray', 'lightgray', 'teal', 'sage', 'sky', 'lavender'. Anything else (including a literal hex) silently clamps to auto.
width	number	Explicit width in px (160–4096).

create_board

Create a fresh board in ONE call — optionally pre-filled with content, auto-laid-out, and/or PIN-locked at create time. Mirrors the extended `POST /api/boards` REST body exactly (same server-side implementation). With no arguments it returns a blank draw board; `mode: 'todo'` (+ optional `template`) seeds a kanban board. `content` imports initial items atomically: everything is validated FIRST and the board is created only if every item passes — on any invalid item you get a structured error naming its kind + index and NOTHING is created. `autolayout: true` (draw mode) fills in x/y for texts/images that omit them (deterministic masonry grid; explicit coordinates are never touched). `lock: 'write'|'all'` locks the board atomically with creation and returns the plaintext `access_key` ONCE — there is no recovery. The response's `imported` counts confirm what was created, `ids` returns the server-minted item ids per kind in the order you supplied them (index i of `ids.texts` is the id created for `content.texts[i]`; `ids.columns` is empty when the columns came from the template seed, and lanes have no id — they are keyed by board + lane index), and `embed_url` (the `?embed=1#<id>` iframe view) is returned for any board readable without a key — it is omitted for `lock:'all'` boards, whose embed frame can't read the board anonymously. Prefer this over open_board + N per-item calls when you are building a whole board from scratch.

Argument	Type	Description
lock	string	PIN-lock the board atomically at create time; the plaintext key is returned ONCE as `access_key`.
mode	string	Board mode. Defaults to 'draw'.
author	string	Author tag stamped on every created item (e.g. 'ai:plai'). Defaults to 'ai:import'.
content	object	Initial board content, applied atomically at create time. Draw mode: `texts` [{x?, y?, content, color?, width?, postit?, diagram?, kind?, author?, sourceId?}], `lines` [{points, color?, anchors?, author?}] (alias `strokes`), `images` [{x?, y?, dataUrl, width, height, author?, sourceId?}]. Todo mode: `columns` [{title, lane?, color?, author?}] (array order = sort order), `tasks` [{columnIndex, name, description?, due_date?, priority?, assignee?, done?, color?, author?}] (columnIndex indexes into content.columns, or into the template-seeded columns when content.columns is empty), `lanes` [{lane, title, author?}], `colWidth`. Every item's optional `author` is its CREATOR tag (same 1-80 char [A-Za-z0-9:_-.] rule as elsewhere) and is never rewritten later — omit it to inherit the top-level `author`, or set it per item to preserve the original authorship when restoring somebody else's board. Item ids are ALWAYS minted server-side and returned in `ids`; you cannot choose them. To keep anchored strokes, give a text/image an optional `sourceId` (unique string, <=128 chars, write-only — never stored, never the row id) and reference it from `lines[].anchors.start.id` / `.end.id`: matching ids are rewritten to the minted id, unmatched ids are left as-is and render as a free stroke end. Kanban structures with a non-todo mode (or draw items with mode 'todo') are rejected with `content_mode_mismatch`. The combined input arrays may contain at most 2550 entries. At most 10 lane-title entries are accepted, every title must reference a lane used by a created column, and each lane index may be named AT MOST ONCE — a second entry for the same lane is rejected (naming that second entry's index) instead of collapsing last-write-wins, which would overwrite the first entry's author. `tasks[].done` must be a real boolean (or omitted/null for not-done): a truthy stand-in such as the string "false" is rejected rather than coerced, so a card is never imported as completed by accident. Standard per-board quotas also apply, and the 5 MB request-body cap is the real ceiling for image-heavy imports. A valid X-Import-Token selects higher REST/MCP and board-create rate tiers, but never changes these content limits.

create_column

Add a kanban column (swimlane) to a 'todo' board. Generates and returns a stable column id. `sort` is a float ordering key (ascending); omit to default to 0. `lane` is an integer row index for multi-row layouts (defaults to 0). `color` is an optional title color ('red' / 'blue' / 'green', or 'auto' / omit for default). To rename, reorder, recolor or move between lanes later use `update_column`.

Argument	Type	Description
lane	integer	Row index for multi-row layouts. Defaults to 0.
sort	number	Float ordering key (ascending). Defaults to 0.
color	string	Title color: 'red', 'blue', 'green', or 'auto' (default).
title*	string
author	string	Author tag, defaults to ai:claude.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "title"
  ],
  "properties": {
    "lane": {
      "type": "integer",
      "description": "Row index for multi-row layouts. Defaults to 0."
    },
    "sort": {
      "type": "number",
      "description": "Float ordering key (ascending). Defaults to 0."
    },
    "color": {
      "type": "string",
      "description": "Title color: 'red', 'blue', 'green', or 'auto' (default)."
    },
    "title": {
      "type": "string"
    },
    "author": {
      "type": "string",
      "description": "Author tag, defaults to ai:claude."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

create_task

Create a task (card) in a column on a 'todo' board. Generates and returns a stable task id. `column_id` must reference an existing column (see `list_tasks`). `description` is free-form prose stored on the card; `priority` is one of 'H' | 'M' | 'L' (omit for none); `due_date` is an ISO 8601 date string; `assignee` is free text (name / initials / email). `sort` is a float ordering key within the column (ascending), defaulting to 0.

Argument	Type	Description
done	boolean	Whether the task is completed (checked off). Defaults to false.
name*	string
sort	number	Float ordering key within the column. Defaults to 0.
author	string	Author tag, defaults to ai:claude.
assignee	string
board_id*	string
due_date	string	ISO 8601 date.
priority	string	High / Medium / Low. Omit for none.
column_id*	string

create_tasks

Bulk-create multiple task cards in one call — far cheaper than calling `create_task` N times. Pass `tasks`: an array of task objects, each with `column_id` (required) + the same fields `create_task` accepts (`name`, `description`, `due_date`, `priority`, `assignee`, `done`, `sort`). Returns the array of created ids in order. Stops at the first invalid item and reports its index; items before it are still created (not transactional).

Argument	Type	Description
tasks*	array	Array of task objects to create.
author	string	Author tag applied to every task, defaults to ai:claude.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "tasks"
  ],
  "properties": {
    "tasks": {
      "type": "array",
      "items": {
        "type": "object",
        "required": [
          "column_id",
          "name"
        ],
        "properties": {
          "done": {
            "type": "boolean"
          },
          "name": {
            "type": "string"
          },
          "sort": {
            "type": "number"
          },
          "assignee": {
            "type": "string"
          },
          "due_date": {
            "type": "string",
            "description": "ISO 8601 date."
          },
          "priority": {
            "enum": [
              "H",
              "M",
              "L"
            ],
            "type": "string"
          },
          "column_id": {
            "type": "string"
          },
          "description": {
            "type": "string"
          }
        }
      },
      "description": "Array of task objects to create."
    },
    "author": {
      "type": "string",
      "description": "Author tag applied to every task, defaults to ai:claude."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

delete_column

Delete a kanban column by id. Tasks in the column are removed with it. Get the id from `list_tasks`.

destructive

Argument	Type	Description
id*	string
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "id"
  ],
  "properties": {
    "id": {
      "type": "string"
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

delete_task

Delete a task (card) by id. Get the id from `list_tasks`.

destructive

Argument	Type	Description
id*	string
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "id"
  ],
  "properties": {
    "id": {
      "type": "string"
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

draw_stroke

Draw a freehand stroke on the board. Use for arrows, underlines, connector lines, annotations, or simple shapes — a straight line needs two points, a rough circle wants ~20. Stroke width is fixed at 3 px; `color` is a NAME, not hex (case-insensitive): 'auto'/''/'black'/omitted for theme-aware ink, or 'red', 'blue', 'green', 'orange', 'yellow', 'pink', 'purple', 'maroon', 'brown', 'gray', 'lightgray', 'teal', 'sage', 'sky', 'lavender' — anything else (including a literal hex like '#ff0000') silently clamps to auto. Accepts three equivalent point formats — pick whichever your MCP client serialises cleanly: nested `[[x,y],[x,y],...]`, flat `[x1,y1,x2,y2,...]`, or a JSON string of either. Some clients (Claude Code as of 2026-04) drop nested arrays during tool-call serialisation, so prefer the flat form or the JSON-string form when in doubt. To delete a stroke later, use `erase` with `kind: 'line'` and the id returned here.

destructive

Argument	Type	Description
id	string
color	string
author	string
points*	any	Points as [[x,y],...], flat [x1,y1,x2,y2,...], or a JSON string of either.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

erase

Delete a single item by id. `kind` MUST match the item type: 'text' for text nodes, 'line' for freehand strokes, 'image' for images — the wrong kind silently targets the wrong table and is a common mistake. Get the id + type from `get_board` (texts[], lines[], images[]). There is no bulk/erase-all tool: loop if you need to delete multiple items.

destructive

Argument	Type	Description
id*	string
kind*	string
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "id",
    "kind"
  ],
  "properties": {
    "id": {
      "type": "string"
    },
    "kind": {
      "enum": [
        "text",
        "line",
        "image"
      ],
      "type": "string"
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

export_tasks

Export a 'todo' board's columns + tasks as a single text document. `format` is 'markdown' (a checklist grouped by column, the default) or 'csv' (one row per task with column/name/priority/assignee/due_date/done). Returns the rendered text. Same data as the GET /api/boards/<id>/tasks.md and tasks.csv REST endpoints.

read-only

Argument	Type	Description
format	string	Output format. Defaults to 'markdown'.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id"
  ],
  "properties": {
    "format": {
      "enum": [
        "markdown",
        "csv"
      ],
      "type": "string",
      "description": "Output format. Defaults to 'markdown'."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

get_board

Full structured JSON state of a board: texts (id, x, y, content, color, width, postit, author), strokes (id, points, color, author), images (id, x, y, width, height, dataUrl, thumbDataUrl, author; heavy base64 >8 kB elided to dataUrl:null, tiny images inlined). Use this for EXACT ids/coordinates/content (needed for `move`, `erase`, editing a text by id). For visual layout (where is empty space? what overlaps?) call `get_preview` instead — it's much cheaper for spatial reasoning than a huge JSON dump.

Argument	Type	Description
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id"
  ],
  "properties": {
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

get_preview

Compact schematic SVG render of the board (typically a few kB even for dense boards). Returns both an image/svg+xml content block (you can SEE it) and the raw SVG text. CALL THIS any time you need to understand where things are — before placing new items, before deciding whether the canvas is crowded, before picking a free region. AI-authored items get a purple border so you can tell which contributions were yours. For precise text content prefer `get_board`.

read-only

Argument	Type	Description
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id"
  ],
  "properties": {
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

list_tasks

Read the full kanban state of a 'todo' board: `{ mode, columns, tasks }`, both ordered by their `sort` key (ascending). Each task carries its hot fields (name, due_date, priority, assignee, done, column_id, sort) plus an opaque `content` JSON string (holds the description). Use this to get exact column/task ids before updating, moving or deleting.

read-only

Argument	Type	Description
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id"
  ],
  "properties": {
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

move

Reposition an existing item to a new (x, y) without retyping its content. Works for every item kind: `text` and `link` set the top-left to (x, y); `line` translates every point so the stroke's bounding box top-left lands at (x, y); `image` sets the top-left like text. `kind` defaults to `text` for backward compat with older callers. Find the id + kind via `get_board`. Prefer `move` over re-creating an item when only the location changes — it preserves the id, content, author and avoids a round-trip of base64 bytes for images.

Argument	Type	Description
x*	number
y*	number
id*	string
kind	string	Item kind. Defaults to `text`.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "id",
    "x",
    "y"
  ],
  "properties": {
    "x": {
      "type": "number"
    },
    "y": {
      "type": "number"
    },
    "id": {
      "type": "string"
    },
    "kind": {
      "enum": [
        "text",
        "link",
        "line",
        "image"
      ],
      "type": "string",
      "description": "Item kind. Defaults to `text`."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

move_task

Move a task to a column at a given sort position — the kanban drag-and-drop primitive. `column_id` is the destination column and `sort` its float order key (ascending) within that column.

Argument	Type	Description
id*	string
sort*	number
board_id*	string
column_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "id",
    "column_id",
    "sort"
  ],
  "properties": {
    "id": {
      "type": "string"
    },
    "sort": {
      "type": "number"
    },
    "board_id": {
      "type": "string"
    },
    "column_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

open_board

ALWAYS call this first when given a board URL or ID. Resolves the canonical board id and auto-creates the board row if it does not exist yet. Returns a summary (item counts, authors). After this, call BOTH `get_preview` and `get_board` before editing so you can see the layout visually AND know the exact ids/coordinates — do not skip `get_preview`, otherwise you will place new items blindly on top of existing ones.

Argument	Type	Description
url_or_id*	string	Full board URL (https://cnvs.app/#<id>) or bare UUID.
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "url_or_id"
  ],
  "properties": {
    "url_or_id": {
      "type": "string",
      "description": "Full board URL (https://cnvs.app/#<id>) or bare UUID."
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

query_tasks

Read tasks from a 'todo' board with server-side filtering — handy for 'what's overdue?' / 'what's assigned to X?' without pulling the whole board. All filters are optional and AND together: `assignee` (exact match), `priority` ('H'|'M'|'L'), `done` (boolean), `overdue` (true → due_date strictly before today, not done), `due_before` / `due_after` (ISO date window on due_date). Returns `{ boardId, mode, tasks }` — tasks ordered by sort, each with the same fields as `list_tasks`.

read-only

Argument	Type	Description
done	boolean
overdue	boolean	Only tasks past due and not done.
assignee	string	Exact-match assignee filter.
board_id*	string
priority	string
due_after	string	ISO date; due_date > this.
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

set_board_mode

Choose whether this board is a freeform whiteboard ('draw', the default) or a kanban task board ('todo'). Mode is switchable WHENEVER the board is empty of real content: drawings (text/strokes/images) and tasks. Empty or seeded columns DON'T count (switching to 'draw' clears them), so a cleared board can be switched again, and you can flip draw<->todo freely until the first stroke/text/image or task lands. Setting 'todo' auto-seeds three starter columns (To do / In progress / Done). Returns `{ mode, columns }`. Use the task/column tools (`create_task`, `create_column`, …) once the board is in 'todo' mode.

destructive

Argument	Type	Description
mode*	string	Board mode.
board_id*	string
template	string	Optional starter column template when mode is 'todo': 'kanban' (To do / In progress / Done, the default), 'sprint' (Backlog / Sprint / Review / Done), or 'bugs' (Triage / Confirmed / In progress / Fixed). Unknown/omitted falls back to 'kanban'.
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "mode"
  ],
  "properties": {
    "mode": {
      "enum": [
        "draw",
        "todo"
      ],
      "type": "string",
      "description": "Board mode."
    },
    "board_id": {
      "type": "string"
    },
    "template": {
      "type": "string",
      "description": "Optional starter column template when mode is 'todo': 'kanban' (To do / In progress / Done, the default), 'sprint' (Backlog / Sprint / Review / Done), or 'bugs' (Triage / Confirmed / In progress / Fixed). Unknown/omitted falls back to 'kanban'."
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

set_column_width

Set the shared kanban column width in pixels for a 'todo' board (all columns share one width). Clamped to [200, 480]. Read the current value as `colWidth` from `list_tasks`.

Argument	Type	Description
width*	number	Column width in px, clamped to [200, 480].
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "width"
  ],
  "properties": {
    "width": {
      "type": "number",
      "description": "Column width in px, clamped to [200, 480]."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

set_lane

Set (or clear) the title of a kanban row (lane). Lanes group columns into horizontal swimlanes; a lane is identified by its integer `lane` index (the same index columns carry). Pass a `title` to name the row, or an empty string to clear it. Read current lane titles + the shared column width via `list_tasks`.

destructive

Argument	Type	Description
lane*	integer	Row index (>= 0).
title	string	Row title; empty string clears it.
author	string	Author tag, defaults to ai:claude.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

{
  "type": "object",
  "required": [
    "board_id",
    "lane"
  ],
  "properties": {
    "lane": {
      "type": "integer",
      "description": "Row index (>= 0)."
    },
    "title": {
      "type": "string",
      "description": "Row title; empty string clears it."
    },
    "author": {
      "type": "string",
      "description": "Author tag, defaults to ai:claude."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}

update_column

Rename, reorder, recolor or move an existing kanban column. Requires the column `id` (from `list_tasks`). Pass `title`, `sort`, `lane` and/or `color` to change them.

destructive

Argument	Type	Description
id*	string
lane	integer	Row index for multi-row layouts.
sort	number	Float ordering key (ascending).
color	string	Title color: 'red', 'blue', 'green', or 'auto' (default).
title	string
author	string	Author tag, defaults to ai:claude.
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.

Input schema (JSON)

update_task

Update an existing task by `id` (from `list_tasks`). Pass only the fields you want to change: `name`, `description`, `due_date`, `priority` ('H'|'M'|'L'), `assignee`, `done` (true once completed), `column_id` (to reassign), `sort`. To move a card between columns while setting its order, `move_task` is the dedicated tool.

destructive

Argument	Type	Description
id*	string
done	boolean	Whether the task is completed (checked off).
name	string
sort	number
author	string	Author tag, defaults to ai:claude.
assignee	string
board_id*	string
due_date	string	ISO 8601 date.
priority	string
column_id

wait_for_update

Long-poll: blocks until the next edit lands on this board, then returns. WHEN TO CALL THIS: if your MCP client does NOT surface `notifications/resources/updated` events from `resources/subscribe` back to the model (most chat clients do not — they receive the SSE event but don't inject it into your context), this tool is how you 'wait for the human' inside a single turn. Typical flow: you draw / write what you were asked to, then instead of ending your turn you call `wait_for_update(board_id)`. When the human adds, moves, or erases something, the call returns and you refresh with `get_preview` / `get_board` and continue the collaboration. Great for turn-based interactions (games like tic-tac-toe, brainstorming where you respond to each sticky the user drops, sketch-and-feedback loops, etc.). If your client DOES deliver resource notifications natively, prefer `resources/subscribe` — it's cheaper and has no timeout ceiling. BEHAVIOUR: resolves ~3 s after the edit burst settles (same debounce as the push notifications — this is intentional so drags and long strokes collapse into one wake-up). Returns `{ updated: true, timedOut: false }` on a real edit, or `{ updated: false, timedOut: true }` if nothing happened within `timeout_ms`. On timeout, just call it again to keep waiting; chaining calls is cheap. `timeout_ms` is clamped to [1000, 55000]; default 25000 (leaves headroom under typical 60 s proxy timeouts).

read-only

Argument	Type	Description
board_id*	string
access_key	string	8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock.
timeout_ms

Input schema (JSON)

{
  "type": "object",
  "properties": {
    "lock": {
      "enum": [
        "write",
        "all"
      ],
      "type": "string",
      "description": "PIN-lock the board atomically at create time; the plaintext key is returned ONCE as `access_key`."
    },
    "mode": {
      "enum": [
        "draw",
        "todo"
      ],
      "type": "string",
      "description": "Board mode. Defaults to 'draw'."
    },
    "author": {
      "type": "string",
      "description": "Author tag stamped on every created item (e.g. 'ai:plai'). Defaults to 'ai:import'."
    },
    "content": {
      "type": "object",
      "description": "Initial board content, applied atomically at create time. Draw mode: `texts` [{x?, y?, content, color?, width?, postit?, diagram?, kind?, author?, sourceId?}], `lines` [{points, color?, anchors?, author?}] (alias `strokes`), `images` [{x?, y?, dataUrl, width, height, author?, sourceId?}]. Todo mode: `columns` [{title, lane?, color?, author?}] (array order = sort order), `tasks` [{columnIndex, name, description?, due_date?, priority?, assignee?, done?, color?, author?}] (columnIndex indexes into content.columns, or into the template-seeded columns when content.columns is empty), `lanes` [{lane, title, author?}], `colWidth`. Every item's optional `author` is its CREATOR tag (same 1-80 char [A-Za-z0-9:_-.] rule as elsewhere) and is never rewritten later — omit it to inherit the top-level `author`, or set it per item to preserve the original authorship when restoring somebody else's board. Item ids are ALWAYS minted server-side and returned in `ids`; you cannot choose them. To keep anchored strokes, give a text/image an optional `sourceId` (unique string, <=128 chars, write-only — never stored, never the row id) and reference it from `lines[].anchors.start.id` / `.end.id`: matching ids are rewritten to the minted id, unmatched ids are left as-is and render as a free stroke end. Kanban structures with a non-todo mode (or draw items with mode 'todo') are rejected with `content_mode_mismatch`. The combined input arrays may contain at most 2550 entries. At most 10 lane-title entries are accepted, every title must reference a lane used by a created column, and each lane index may be named AT MOST ONCE — a second entry for the same lane is rejected (naming that second entry's index) instead of collapsing last-write-wins, which would overwrite the first entry's author. `tasks[].done` must be a real boolean (or omitted/null for not-done): a truthy stand-in such as the string \"false\" is rejected rather than coerced, so a card is never imported as completed by accident. Standard per-board quotas also apply, and the 5 MB request-body cap is the real ceiling for image-heavy imports. A valid X-Import-Token selects higher REST/MCP and board-create rate tiers, but never changes these content limits."
    },
    "template": {
      "enum": [
        "kanban",
        "sprint",
        "bugs"
      ],
      "type": "string",
      "description": "Starter column set when mode is 'todo' and content.columns is empty/absent. Defaults to 'kanban'."
    },
    "autolayout": {
      "type": "boolean",
      "description": "Draw mode only: fill x/y for texts/images that omit them (deterministic masonry). Without it, items missing coordinates are rejected. No-op in todo mode."
    }
  }
}

{
  "type": "object",
  "required": [
    "board_id",
    "id"
  ],
  "properties": {
    "id": {
      "type": "string"
    },
    "lane": {
      "type": "integer",
      "description": "Row index for multi-row layouts."
    },
    "sort": {
      "type": "number",
      "description": "Float ordering key (ascending)."
    },
    "color": {
      "type": "string",
      "description": "Title color: 'red', 'blue', 'green', or 'auto' (default)."
    },
    "title": {
      "type": "string"
    },
    "author": {
      "type": "string",
      "description": "Author tag, defaults to ai:claude."
    },
    "board_id": {
      "type": "string"
    },
    "access_key": {
      "type": "string",
      "description": "8-character lowercase alphanumeric board access key when the board is locked (legacy 6-character lowercase alphanumeric keys are also accepted). Equivalent to setting the `X-Board-Key` HTTP header on the JSON-RPC POST. Omit for unlocked boards. Obtain via POST /api/boards/<id>/lock."
    }
  }
}