components_v2_validate

Validate a Components V2 components array OFFLINE (no Discord API call). Enforces the 40-cap, placement and nesting rules, ActionRow cardinality, Button style contracts, unique custom_id values, accessory requirements, and MediaGallery range. File components are rejected because the current send/edit tools do not upload attachments.

When to use

iterate on a layout before sending. Saves round-trips for agents constructing complex cards.

MCP call example

{
  "name": "components_v2_validate",
  "arguments": {
    "components": [
      {
        "type": 10,
        "content": "Hello from discord-mcp"
      }
    ]
  }
}

Input

Field	Type	Required	Constraints	Description
`components`	array<unknown>	yes		Components array (will be validated)

Complete input JSON Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "components": {
      "type": "array",
      "items": {},
      "description": "Components array (will be validated)"
    }
  },
  "required": [
    "components"
  ]
}

Returns

{valid, issues:[{path, code, message, fix_hint?}]}.

Example structured result

{
  "valid": true,
  "issues": [
    {
      "path": "example",
      "code": "example",
      "message": "Hello from discord-mcp"
    }
  ]
}

Output schema

Field	Type	Required	Constraints	Description
`valid`	boolean	yes
`issues`	array<object>	yes

Complete output JSON Schema

{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "type": "object",
  "properties": {
    "valid": {
      "type": "boolean"
    },
    "issues": {
      "type": "array",
      "items": {
        "type": "object",
        "properties": {
          "path": {
            "type": "string"
          },
          "code": {
            "type": "string"
          },
          "message": {
            "type": "string"
          },
          "fix_hint": {
            "type": "string"
          }
        },
        "required": [
          "path",
          "code",
          "message"
        ],
        "additionalProperties": false
      }
    }
  },
  "required": [
    "valid",
    "issues"
  ],
  "additionalProperties": false
}

Annotations

Property	Value
Read-only	yes
Destructive	no
Idempotent	yes
Open-world	no
Confirmation required	no

Access and common errors

The components_v2 category must be enabled by MCP_CATEGORIES when an allowlist is set.
Access contract: scope=local; this tool uses no Discord credential (local or external operation) and is scoped to the local compiler/validator only.
No named Discord permission bit is asserted by this contract.
Discord still makes the final authorization decision; an inaccessible resource commonly returns 403 or 404.

Source

packages/mcp-core/src/tools/components-v2/validate.ts