# Deep Research MCP Server
[](https://nodejs.org/)
[](https://www.typescriptlang.org/)
[](https://makersuite.google.com/app/apikey)
[](https://github.com/modelcontextprotocol)
[](https://opensource.org/licenses/MIT)
**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](#features)
* [Why This Project](#why-this-project)
* [Workflow Diagram](#workflow-diagram)
* [Persona Agents](#persona-agents)
* [How It Works](#how-it-works)
* [Project Structure](#project-structure)
* [Requirements](#requirements)
* [Setup](#setup)
* [Usage](#usage)
* [As MCP Tool](#as-mcp-tool)
* [Standalone CLI Usage](#standalone-cli-usage)
* [MCP Inspector Testing](#mcp-inspector-testing)
* [Configuration](#configuration)
* [Quickstart](#quickstart)
* [Example Output](#example-output)
* [Support](#support)
* [Contributing](#contributing)
* [Roadmap](#roadmap)
* [License](#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
```mermaid
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
```text
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](https://nodejs.org/) v22.x
* [Google Gemini API key](https://makersuite.google.com/app/apikey)
## Setup
### Node.js
1. **Clone the repository:**
```bash
git clone [your-repo-link-here]
```
2. **Install dependencies:**
```bash
npm install
```
3. **Set up environment variables:** Create a `.env.local` file in the project root:
```bash
# 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:**
```bash
npm run build
```
## Usage
### As MCP Tool
To run `deep-research` as an MCP tool, start the MCP server:
```bash
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):**
```json
{
"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"
]
}
}
```
```typescript
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:
```bash
npm run start "your research query"
```
**Example:**
```bash
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:
```bash
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
```bash
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](#setup))
3) Run as MCP server (Inspector)
```bash
npx @modelcontextprotocol/inspector node --env-file .env.local dist/mcp-server.js
```
4) Or run as CLI
```bash
npm run start "state of multi-agent research agents in 2025"
```
## Example Output
```markdown
# 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](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](#roadmap).
<details>
<summary><strong>🧪 Enhanced Research Validation</strong></summary>
* ✅ 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
</details>
<details>
<summary><strong>🧠 Gemini Integration Upgrades</strong></summary>
* 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
</details>
<details>
<summary><strong>🧹 Code Quality Improvements</strong></summary>
* 🚀 Added concurrent processing pipeline
* Removed redundant academic-validators module
* 🛡️ Enhanced type safety across interfaces
* 📦 Optimized dependencies (≈30% smaller node_modules)
</details>
<details>
<summary><strong>🆕 New Features</strong></summary>
* 📊 Research metrics tracking (sources/learnings ratio)
</details>
* 📑 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
