Brain in the Fish
Score any document. Prove every claim.
What is Brain in the Fish?
Brain in the Fish is a Model Context Protocol (MCP) server that allows AI assistants like Claude, Cursor, and VS Code to score any document. prove every claim.
Score any document. Prove every claim.
This server falls under the Knowledge & Memory category on MCPgee, the world's largest MCP server directory with 33,000+ servers.
Features
- Score any document. Prove every claim.
Use Cases
Maintainer
Works with
Installation
Manual Installation
npx brain-in-the-fishConfiguration
Configuration Details
claude_desktop_config.json
Performance
Response Metrics
Resource Usage
How to Set Up and Use Brain in the Fish
Brain in the Fish is a locally-running MCP server that scores documents for factual integrity and verifies individual claims against evidence. Built in Rust, it uses OWL ontologies and SPARQL queries to evaluate documents — such as PDFs, research papers, or tenders — and returns a verdict with an evidence trail. It is designed for anti-hallucination workflows where every AI-generated claim must be grounded in a verifiable source, without sending data to any external API.
Prerequisites
- Rust toolchain (2024 edition or later) with `cargo` available
- Git, to clone both the `brain-in-the-fish` and the companion `open-ontologies` repositories
- An MCP-compatible client such as Claude Desktop
- No external API keys required — the server runs entirely offline
Clone the open-ontologies dependency
Brain in the Fish depends on a companion ontologies library. Clone it first so the build can find it.
git clone https://github.com/fabio-rovai/open-ontologies.gitClone the main repository
Clone the brain-in-the-fish repository into the same parent directory as open-ontologies.
git clone https://github.com/fabio-rovai/brain-in-the-fish.git
cd brain-in-the-fishBuild the release binary
Compile the Rust project in release mode. The resulting binary will be at `target/release/brain-in-the-fish`.
cargo build --releaseRun the demo to verify the build
Execute the built-in demo to confirm the binary works correctly. It runs three evaluation examples and prints verdicts to stdout.
./target/release/brain-in-the-fish demoConfigure your MCP client
Point your MCP client at the compiled binary. Add the block below to your Claude Desktop config, substituting the actual path to the built binary.
Evaluate a document
Use the CLI directly or through the MCP server to score a PDF. The `--verify` flag enables web-based evidence lookup; `--badge` outputs a visual trust badge.
./target/release/brain-in-the-fish evaluate your-document.pdf --intent "assess methodology" --verifyBrain in the Fish Examples
Client configuration
Add this block to your Claude Desktop configuration file. Replace the path with the absolute path to the compiled binary on your system.
{
"mcpServers": {
"brain-in-the-fish": {
"command": "/absolute/path/to/brain-in-the-fish/target/release/brain-in-the-fish-mcp"
}
}
}Prompts to try
These prompts exercise the document scoring and claim verification capabilities of the server inside your AI client.
- "Score this research paper for factual accuracy and flag any unsupported claims"
- "Evaluate the attached tender document and produce a verdict with evidence"
- "Check whether the claim 'X causes Y' is supported by the evidence in this PDF"
- "Run the document evaluator on report.pdf and generate a trust badge"Troubleshooting Brain in the Fish
Build fails with a missing `open-ontologies` crate error
Ensure the `open-ontologies` repository is cloned into the same parent directory as `brain-in-the-fish`. The Cargo workspace expects both repos side by side.
MCP client cannot find the binary
Use the absolute path to `target/release/brain-in-the-fish-mcp` in the config (not the relative path). Confirm the binary is executable with `chmod +x`.
Evaluation returns no verdict on a PDF
Verify the PDF is machine-readable (not a scanned image). The `--intent` flag is required to guide evaluation — provide a descriptive intent string such as 'assess methodology'.
Frequently Asked Questions about Brain in the Fish
What is Brain in the Fish?
Brain in the Fish is a Model Context Protocol (MCP) server that score any document. prove every claim. It connects AI assistants to external tools and data sources through a standardized interface.
How do I install Brain in the Fish?
Follow the installation instructions on the Brain in the Fish GitHub repository. Clone the repo, install dependencies, and add the server config to your AI client.
Which AI clients work with Brain in the Fish?
Brain in the Fish works with all major MCP-compatible AI clients including Claude Desktop, Claude Code, Cursor, VS Code (GitHub Copilot), Windsurf, and Cline.
Is Brain in the Fish free to use?
Yes, Brain in the Fish is open source and available under the MIT license. You can use it freely in both personal and commercial projects.
Brain in the Fish Alternatives — Similar Knowledge & Memory Servers
Looking for alternatives to Brain in the Fish? Here are other popular knowledge & memory servers you can use with Claude, Cursor, and VS Code.
MemPalace
★ 52.6kA local AI memory system that stores all conversations verbatim and organizes them into navigable structures. It provides 19 MCP tools for AI assistants to search and retrieve past decisions, debugging sessions, and architecture debates automatically
Kratos
★ 25.7k🏛️ Memory System for AI Coding Tools - Never explain your codebase again. MCP server with perfect project isolation, 95.8% context accuracy, and the Four Pillars Framework.
Context Mode
★ 15.4kAn MCP server that preserves LLM context by intercepting large data outputs and returning only concise summaries or relevant sections. It enables efficient sandboxed code execution, file processing, and documentation indexing across multiple programm
Memu
★ 13.7kMemory for 24/7 proactive agents like OpenClaw.
MemOS
★ 9.3kMemOS (Memory Operating System) is a memory management operating system designed for AI applications. Its goal is: to enable your AI system to have long-term memory like a human, not only remembering what users have said but also actively invoking, u
Everos
★ 5.4kBuild, evaluate, and integrate long-term memory for self-evolving agents.
Browse More Knowledge & Memory MCP Servers
Explore all knowledge & memory servers available in the MCPgee directory. Each server includes setup guides for Claude, Cursor, and VS Code.
Set Up Brain in the Fish in Your Editor
Choose your AI client for step-by-step setup instructions.
Quick Config Preview
Add this to your claude_desktop_config.json or .cursor/mcp.json
Ready to use Brain in the Fish?
Browse our complete directory of 33,000+ MCP servers, read setup guides for your editor, and start building with the Model Context Protocol.