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Claude Agent provider does not pass MCP servers or plugins to the SDK #1271

@AssahBismarkabah

Description

@AssahBismarkabah

Before submitting

  • I searched existing issues and did not find a duplicate.
  • I included enough detail to reproduce or investigate the problem.

Area

apps/server

Description

When using the Claude Agent provider (claudeAgent), T3 Code does not forward MCP server configurations or plugins to the Claude Agent SDK's query() function.

The SDK init event confirms empty MCP and plugins:

"mcp_servers": [],
"plugins": []

Steps to reproduce

  1. Configure MCP servers in ~/.claude/settings.json
  2. Open T3 Code (Alpha), start a thread using the Claude Agent provider
  3. Ask Claude to use an MCP tool
  4. Claude has no access to any MCP servers

Root Cause

In apps/server/dist/index.mjs, the queryOptions object passed to createQuery() inside makeClaudeAdapter includes cwd, model, effort, permissionMode, settings, env, and additionalDirectories — but no mcpServers or plugins parameter.

const queryOptions = {
    ...input.cwd ? { cwd: input.cwd } : {},
    ...input.model ? { model: input.model } : {},
    pathToClaudeCodeExecutable: providerOptions?.binaryPath ?? "claude",
    ...effectiveEffort ? { effort: effectiveEffort } : {},
    ...permissionMode ? { permissionMode } : {},
    // ... other options
    // No mcpServers
    // No plugins
};

The Claude Agent SDK's query() function supports these options, but T3 Code doesn't pass them through.

Expected behavior

MCP servers configured locally should be forwarded to the Claude Agent SDK so MCP tools are available in Claude Agent sessions.

Actual behavior

Claude Agent sessions start with "mcp_servers": [] and "plugins": [], making all MCP tools unavailable.

Impact

Blocks use of any MCP tools when using the Claude Agent provider.

Version

  • T3 Code (Alpha) v0.0.13
  • Bundled Claude Agent SDK: 2.1.81
  • macOS (Apple Silicon)

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