Validation with VineJS

You can validate tool, resource, or prompt arguments with VineJS for complex validation rules or to reuse validators from your AdonisJS routes.

Installation and configuration

When you install the package with:

node ace add @jrmc/adonis-mcp

the installer asks "Is Vinejs used for validation?" (Yes / No). If you choose Yes, the VineJS provider is registered and request.validateUsing() is available in your MCP handlers. If you choose No, the provider is not added and you use only JSON Schema (or Zod) for validation.

To enable VineJS after installation, add the provider manually in adonisrc.ts:

providers: [
  // ...
  '@jrmc/adonis-mcp/vinejs_provider',
]

Usage

request.validateUsing() is available in Tools, Resources, and Prompts handlers. Two approaches are available.

Standard approach

Validate manually and handle errors with try/catch:

import type { ToolContext } from '@jrmc/adonis-mcp/types/context'
import { Tool } from '@jrmc/adonis-mcp'
import Article from '#models/article'
import { ArticleValidator } from '#validators/article'

export default class CreateArticleTool extends Tool {
  // ...

  async handle({ args, response }: ToolContext) {
    try {
      const payload = await ArticleValidator.validate(args)

      const article = await Article.create(payload)
      return response.text(`Article "${article.title}" created successfully with id: ${article.id}`)
    } catch (error) {
      return response.error('Error: ' + error.message)
    }
  }
}

Recommended approach (AdonisJS-style)

Use request.validateUsing(). Validation errors are automatically turned into JSON-RPC error responses, so no try/catch is needed:

import type { ToolContext } from '@jrmc/adonis-mcp/types/context'
import { Tool } from '@jrmc/adonis-mcp'
import Article from '#models/article'
import { ArticleValidator } from '#validators/article'

export default class CreateArticleTool extends Tool {
  // ...

  async handle({ response, request }: ToolContext) {
    const payload = await request.validateUsing(ArticleValidator)

    const article = await Article.create(payload)
    return response.text(`Article "${article.title}" created successfully with id: ${article.id}`)
  }
}

The same pattern applies in Resources and Prompts: inject request in your handler and call request.validateUsing(YourValidator) with the same VineJS validators you use in your HTTP routes.