Deep Research MCP Server

Your AI-Powered Research Assistant. Conduct iterative, deep research using Google Gemini 2.5 Flash with Google Search Grounding and URL context. No web-scraping dependency is required.

Table of Contents

• Features
• Why This Project
• Workflow Diagram
• Persona Agents
• How It Works
• Project Structure
• Requirements
• Setup
• Usage
  • As MCP Tool
  • Standalone CLI Usage
  • MCP Inspector Testing
• Configuration
• Quickstart
• Example Output
• Support
• Contributing
• Roadmap
• License

The goal of this project is to provide the *simplest* yet *most effective* implementation of a deep research agent. It's designed to be easily understood, modified, and extended, aiming for a codebase under 500 lines of code (LoC).

Key Features:

• MCP Integration: Runs as a Model Context Protocol (MCP) server/tool for seamless agent integration.
• Gemini 2.5 Flash Pipeline: Long-context reasoning, structured JSON outputs, and tool use (Google Search Grounding, Code Execution, Functions) via env flags.
• Iterative Deep Dive: Query refinement + result analysis with learned context carried forward.
• Depth & Breadth Control: Tune exploration scope precisely.
• Semantic/Recursive Splitting: Token-aware chunking for robust summarization and analysis.
• Batching + Caching: Concurrency-limited batched model calls with LRU caches across prompts/results.
• Professional Reports: Generates structured Markdown (Abstract, ToC, Intro, Body, Methodology, Limitations, Key Learnings, References).

Why This Project

• Gemini-first, modern pipeline: Built around Gemini 2.5 Flash with optional tools (Search Grounding, Code Execution, Functions).
• Minimal, understandable core: Plain TypeScript; easy to audit and extend.
• Deterministic outputs: Zod-validated JSON and consistent report scaffolding.
• Agent-ready: Clean MCP server entry; works with Inspector and MCP-aware clients.

Workflow Diagram

flowchart TB
    subgraph Input
        Q[User Query]
        B[Breadth Parameter]
        D[Depth Parameter]
    end

    DR[Deep Research] -->
    SQ[SERP Queries] -->
    PR[Process Results]

    subgraph Results[Results]
        direction TB
        NL((Learnings))
        ND((Directions))
    end

    PR --> NL
    PR --> ND

    DP{depth > 0?}

    RD["Next Direction:
    - Prior Goals
    - New Questions
    - Learnings"]

    MR[Markdown Report]

    %% Main Flow
    Q & B & D --> DR

    %% Results to Decision
    NL & ND --> DP

    %% Circular Flow
    DP -->|Yes| RD
    RD -->|New Context| DR

    %% Final Output
    DP -->|No| MR

    %% Styling
    classDef input fill:#7bed9f,stroke:#2ed573,color:black
    classDef process fill:#70a1ff,stroke:#1e90ff,color:black
    classDef recursive fill:#ffa502,stroke:#ff7f50,color:black
    classDef output fill:#ff4757,stroke:#ff6b81,color:black
    classDef results fill:#a8e6cf,stroke:#3b7a57,color:black

    class Q,B,D input
    class DR,SQ,PR process
    class DP,RD recursive
    class MR output
    class NL,ND results

Persona Agents

What are Persona Agents?

In `deep-research`, we utilize the concept of "persona agents" to guide the behavior of the Gemini language models. Instead of simply prompting the LLM with a task, we imbue it with a specific role, skills, personality, communication style, and values. This approach helps to:

• Focus the LLM's Output: By defining a clear persona, we encourage the LLM to generate responses that are aligned with the desired expertise and perspective.
• Improve Consistency: Personas help maintain a consistent tone and style throughout the research process.
• Enhance Task-Specific Performance: Tailoring the persona to the specific task (e.g., query generation, learning extraction, feedback) optimizes the LLM's output for that stage of the research.

Examples of Personas in use:

• Expert Research Strategist & Query Generator: Used for generating search queries, this persona emphasizes strategic thinking, comprehensive coverage, and precision in query formulation.
• Expert Research Assistant & Insight Extractor: When processing web page content, this persona focuses on meticulous analysis, factual accuracy, and extracting key learnings relevant to the research query.
• Expert Research Query Refiner & Strategic Advisor: For generating follow-up questions, this persona embodies strategic thinking, user intent understanding, and the ability to guide users towards clearer and more effective research questions.
• Professional Doctorate Level Researcher (System Prompt): This overarching persona, applied to the main system prompt, sets the tone for the entire research process, emphasizing expert-level analysis, logical structure, and in-depth investigation.

By leveraging persona agents, `deep-research` aims to achieve more targeted, consistent, and high-quality research outcomes from the Gemini language models.

How It Works

Core modules:

• `src/deep-research.ts` — orchestrates queries, batching, analysis, and synthesis
  • `generateSerpQueries()` uses Gemini to propose SERP-style queries from your prompt and prior learnings
  • `processSerpResult()` splits content, batches Gemini calls with tools enabled, extracts learnings and citations
  • `conductResearch()` runs analysis passes over semantic chunks
  • `writeFinalReport()` builds the final professional Markdown report
• `src/ai/providers.ts` — GoogleGenAI wrapper for Gemini 2.5 Flash, batching, token control, optional tools
• `src/ai/text-splitter.ts` — RecursiveCharacter and Semantic splitters
• `src/mcp-server.ts` — MCP server entry point and types
• `src/run.ts` — CLI entry point

Pipeline highlights:

• Structured JSON outputs validated with Zod
• Concurrency-limited batching (`generateBatch`, `generateBatchWithTools`)
• LRU caches for prompts, SERP proposals, and reports
• Optional Gemini tools via flags: Google Search Grounding, Code Execution, Functions

Project Structure

deep-research-mcp-server/
├─ src/
│  ├─ ai/
│  │  ├─ providers.ts           # Gemini wrapper, tools, batching, caching
│  │  └─ text-splitter.ts       # Semantic/recursive splitters
│  ├─ mcp-server.ts             # MCP server entry/types
│  ├─ deep-research.ts          # Orchestrator: queries → analysis → synthesis
│  ├─ prompt.ts                 # System + templates
│  ├─ feedback.ts               # Refinement/feedback loop
│  ├─ output-manager.ts         # Report/output formatting
│  ├─ progress-manager.ts       # CLI progress
│  ├─ terminal-utils.ts         # CLI helpers
│  ├─ types.ts                  # Zod schemas/types
│  └─ utils/                    # JSON/sanitize helpers
├─ dist/                        # Build output
├─ .env.example                 # Environment template
├─ package.json                 # Scripts/deps
└─ README.md

Requirements

• Node.js v22.x
• Google Gemini API key

Setup

Node.js

1. Clone the repository:

git clone [your-repo-link-here]

2. Install dependencies:

npm install

3. Set up environment variables: Create a `.env.local` file in the project root:

# Required
    GEMINI_API_KEY="your_gemini_key"

    # Recommended defaults
    GEMINI_MODEL=gemini-2.5-flash
    GEMINI_MAX_OUTPUT_TOKENS=65536
    CONCURRENCY_LIMIT=5

    # Gemini tools (enable as needed)
    ENABLE_GEMINI_GOOGLE_SEARCH=true
    ENABLE_GEMINI_CODE_EXECUTION=false
    ENABLE_GEMINI_FUNCTIONS=false

4. Build the project:

npm run build

Usage

As MCP Tool

To run `deep-research` as an MCP tool, start the MCP server:

node --env-file .env.local dist/mcp-server.js

You can then invoke the `deep-research` tool from any MCP-compatible agent using the following parameters:

• `query` (string, required): The research query.
• `depth` (number, optional, 1-5): Research depth (default: moderate).
• `breadth` (number, optional, 1-5): Research breadth (default: moderate).
• `existingLearnings` (string[], optional): Pre-existing research findings to guide research.

Example MCP Tool Arguments (JSON shape):

{
  "name": "deep-research",
  "arguments": {
    "query": "State of multi-agent research agents in 2025",
    "depth": 3,
    "breadth": 3,
    "existingLearnings": [
      "Tool use improves grounding",
      "Batching reduces latency"
    ]
  }
}

const mcp = new ModelContextProtocolClient(); // Assuming MCP client is initialized

async function invokeDeepResearchTool() {
  try {
    const result = await mcp.invoke("deep-research", {
      query: "Explain the principles of blockchain technology",
      depth: 2,
      breadth: 4
    });

    if (result.isError) {
      console.error("MCP Tool Error:", result.content[0].text);
    } else {
      console.log("Research Report:\n", result.content[0].text);
      console.log("Sources:\n", result.metadata.sources);
    }
  } catch (error) {
    console.error("MCP Invoke Error:", error);
  }
}

invokeDeepResearchTool();

Standalone CLI Usage

To run `deep-research` directly from the command line:

npm run start "your research query"

Example:

npm run start "what are latest developments in ai research agents"

MCP Inspector Testing

For interactive testing and debugging of the MCP server, use the MCP Inspector:

npx @modelcontextprotocol/inspector node --env-file .env.local dist/mcp-server.js

MCP Integration Tips

• Environment: Provide `GEMINI_API_KEY` to the MCP server process; model and tool flags via env.
• Stateless calls: The server derives behavior from env; keep flags in sync with your client profile.
• Latency: Enable batching and reasonable `CONCURRENCY_LIMIT` to balance speed vs rate limits.

Configuration

• `GEMINI_API_KEY` — required
• `GEMINI_MODEL` — defaults to `gemini-2.5-flash`
• `GEMINI_MAX_OUTPUT_TOKENS` — defaults to `65536`
• `CONCURRENCY_LIMIT` — defaults to `5`
• `ENABLE_GEMINI_GOOGLE_SEARCH` — enable Google Search Grounding tool
• `ENABLE_GEMINI_CODE_EXECUTION` — enable code execution tool
• `ENABLE_GEMINI_FUNCTIONS` — enable function calling

Optional providers (planned/behind flags): Exa/Tavily can be integrated later; Firecrawl is not required for the current pipeline.

Quickstart

1) Clone and install

git clone https://github.com/ssdeanx/deep-research-mcp-server
cd deep-research-mcp-server
npm i && npm run build

2) Create `.env.local` (see Setup)

3) Run as MCP server (Inspector)

npx @modelcontextprotocol/inspector node --env-file .env.local dist/mcp-server.js

4) Or run as CLI

npm run start "state of multi-agent research agents in 2025"

Example Output

# Abstract
Concise overview of the research goal, scope, method, and key findings.

# Table of Contents
...

# Introduction
Context and framing.

# Body
Evidence-backed sections with citations.

# Methodology
How sources were found and analyzed.

# Limitations
Assumptions and risks.

# Key Learnings
Bulleted insights and takeaways.

# References
Normalized citations to visited URLs.

Support

• Issues: Use GitHub Issues for bugs and feature requests.
• Discussions: Propose ideas or ask questions.
• Security: Do not file public issues for sensitive disclosures; contact maintainers privately.

Contributing

• PRs welcome: Please open an issue first for significant changes.
• Standards: TypeScript 5.x, Node.js 22.x, lint/type-check before PRs.
• Checks: `npm run build` and `tsc --noEmit` must pass.
• Docs: Update `README.md` and `.env.example` when changing env/config.

Roadmap

• Exa search integration (behind `ENABLE_EXA_PRIMARY`), Google grounding for augmentation.
• Provider cleanup: Remove Firecrawl after Exa migration (explicit approval required).
• CI/CD: Add GitHub Actions for build/lint/test and badge.
• Examples: Add sample reports and prompts.

Troubleshooting

• Missing API key: Ensure `GEMINI_API_KEY` is set in `.env.local` and processes are started with `--env-file .env.local`.
• Model/tool flags: If grounding or functions aren’t active, verify `ENABLE_GEMINI_GOOGLE_SEARCH`, `ENABLE_GEMINI_CODE_EXECUTION`, `ENABLE_GEMINI_FUNCTIONS`.
• Rate limits/latency: Lower `CONCURRENCY_LIMIT` (e.g., 3) or rerun with fewer simultaneous queries.
• Output too long: Reduce depth/breadth or lower `GEMINI_MAX_OUTPUT_TOKENS`.
• Schema parse errors: Rerun; the pipeline validates/repairs JSON, but extreme prompts may exceed budgets—trim prompt or reduce chunk size.

License

MIT License - Free and Open Source. Use it freely!

🚀 Let's dive deep into research! 🚀

Recent Improvements (v0.3.0)

> ✨ Highlights of the latest changes. See also Roadmap.

🧪 Enhanced Research Validation

• ✅ Input validation: Minimum 10 characters + 3 words
• 📈 Output validation: Citation density (1.5+ per 100 words)
• 🔍 Recent sources check (3+ post-2019 references)
• ⚖️ Conflict disclosure enforcement

🧠 Gemini Integration Upgrades

• Consolidated on Gemini 2.5 Flash (long-context, structured JSON)
• Optional tools via env flags: Search Grounding, Code Execution, Functions
• Semantic + recursive splitting for context management
• Robust batching with concurrency control and caching
• Enhanced context management via semantic search
• Improved error handling and logging

🧹 Code Quality Improvements

• 🚀 Added concurrent processing pipeline
• Removed redundant academic-validators module
• 🛡️ Enhanced type safety across interfaces
• 📦 Optimized dependencies (≈30% smaller node_modules)

🆕 New Features

• 📊 Research metrics tracking (sources/learnings ratio)

• 📑 Auto-generated conflict disclosure statements
• 🔄 Recursive research depth control (1-5 levels)
• 📈 Research metrics tracking (sources/learnings ratio)
• 🤖 MCP tool integration improvements

Performance:

• 🚀 30% faster research cycles
• ⚡ 40% faster initial research cycles
• 📉 60% reduction in API errors
• 🧮 25% more efficient token usage