feat: add You.com Search and Research as web search provider

[ydc-oss-bot]

Summary

Adds You.com Search and Research APIs as a new MCP server provider, following the existing Serper (Google Search) and Sogou Search MCP server pattern.

Changes

New file: youcom_search_mcp_server.py

A standalone FastMCP server exposing two tools:

• youcom_search — Web search via the You.com Search API (POST /v1/agents/search). Returns organic results (title, url, snippet) and images.
• youcom_research — Multi-step research via the You.com Research API (POST /v1/research). Returns a synthesized, well-cited answer with supporting sources. Supports research_effort levels: lite, standard, deep, exhaustive.

Both tools use YDC_API_KEY env var (X-API-Key header), with retry logic (tenacity) and input validation.

Modified: settings.py

• Added YOUCOM_API_KEY env var (reads YDC_API_KEY)
• Registered tool-youcom-search in create_mcp_server_parameters() — launches the You.com MCP server as a stdio subprocess, same pattern as tool-google-search and tool-sogou-search
• Added has_ydc_api_key to get_env_info() for logging

Modified: .env.example

Added YDC_API_KEY entry under a new "You.com Search & Research (optional)" section.

New file: test_youcom_search_mcp_server.py

7 unit tests covering input validation (missing API key, empty query, invalid research effort) and success paths (mocked API responses) for both tools.

Usage

Add tool-youcom-search to an agent's tools list in the config YAML:

sub_agents:
  agent-browsing:
    tools:
      - tool-youcom-search   # You.com Search + Research
      - tool-vqa
      - tool-reader

Set the API key:

export YDC_API_KEY=your_...t

The agent will then have access to youcom_search (fast web search) and youcom_research (deep research with citations) tools.

Testing

python3 libs/miroflow-tools/tests/test_youcom_search_mcp_server.py
# All 7 tests passed.

All Python files pass py_compile checks.