add_column

Adds one column to a table. Existing rows get NULL, or the column’s default if it has one.


Scope	`mcp:write`
Annotations	`readOnlyHint: false`
Activity event	`column.added`

Parameters

string

required

Project id from list_projects. You need write access.

string

required

Table name.

object

required

The column to add.

Show properties

string

required

Column name. See Naming rules. id and created_at are reserved.

string

required

One of text, integer, numeric, boolean, timestamptz, uuid, jsonb.

boolean

default:"true"

false makes the column NOT NULL. A NOT NULL column without a default can only be added to an empty table.

string

now() for timestamptz, or gen_random_uuid() for uuid.

Result

The table’s updated definition. Same shape as the describe_table result.

Example

Arguments

{
  "projectId": "01k7m3x9q2v8d4h6n1r5t0w2yz",
  "table": "books",
  "column": { "name": "finished_on", "type": "timestamptz" }
}

Result

{
  "data": {
    "table": "books",
    "columns": [
      { "name": "id", "type": "uuid", "nullable": false, "default": "gen_random_uuid()" },
      { "name": "created_at", "type": "timestamptz", "nullable": false, "default": "now()" },
      { "name": "title", "type": "text", "nullable": false },
      { "name": "rating", "type": "integer" },
      { "name": "finished_on", "type": "timestamptz" }
    ]
  }
}

Errors

Code	When
`ACCESS_DENIED`	You don’t have write access, or the connection is read-only
`VALIDATION`	Unknown table, invalid name, unsupported type or default, or a `NOT NULL` column without a default on a table that has rows
`CONFLICT`	The column already exists
`QUOTA_EXCEEDED`	The table already has 50 columns, or the project’s storage is full

Notes

To add a foreign key, the column must be created with the table. See Foreign keys.
To make an existing nullable column required, add a new NOT NULL column with a default, or create a new table and copy the rows.

Overview

Read tools

Write tools

Destructive tools

Parameters

Result

Example

Errors

Notes

​Parameters

​Result

​Example

​Errors

​Notes

Parameters

Result

Example

Errors

Notes