MCP Client Runtime

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Discover and call

import {
  McpClientRuntimeCapability,
  type McpClientScope,
  type McpClientToolCall,
  type RuntimeCapabilityRegistry
} from '@xpert-ai/plugin-sdk'

export async function callApprovedTool(
  capabilities: RuntimeCapabilityRegistry,
  scope: McpClientScope,
  request: McpClientToolCall
) {
  const client = capabilities.require(McpClientRuntimeCapability)
  const tools = await client.tools.list(scope)
  const selected = tools.find((tool) => tool.name === request.toolName)
  if (!selected || selected.contractHash !== request.contractHash) {
    throw new Error('Rediscover and approve the changed tool contract')
  }
  return client.tools.call(scope, request)
}

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Tool policy and results

• Eligible tools are enabled and model-visible, declare readOnlyHint: true, and do not declare destructiveHint: true or require task execution. Read-only hints narrow selection; they neither grant access nor prove remote behavior.
• contractHash pins schemas and annotations, not remote code or authorization. Changed contracts require rediscovery and explicit caller review.
• Arguments and structured output undergo JSON Schema validation without coercion. Interaction requests, tool errors and invalid output fail.
• Results contain optional structuredContent and plain text blocks. Accept text JSON only when your application’s contract explicitly permits it. Resource links are not fetched automatically.

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Execution limits