Drasil MCP Server — Documentation

Overview

The Drasil MCP server gives Claude access to a structured reasoning protocol for solving math problems. When Claude encounters a math problem, it calls the drasil_protocol tool, loads the protocol, solves the problem with exact arithmetic, then discards the protocol. Nothing persists between problems.

Transport: Streamable HTTP (JSON-RPC 2.0 over POST)
Hosted on Cloudflare Workers — global edge, <50ms response
No dependencies, no local install, no API keys to manage separately
Works with Claude Web, Claude Desktop, Claude Code, and Claude API

Quick Start

Add this MCP server config to your Claude client. The public trial key is included — no signup required.

Claude Desktop

Open Settings → Developer → Edit Config, and add:

{
  "mcpServers": {
    "drasil": {
      "type": "url",
      "url": "https://mcp.yggdrasilapi.com/DRASIL-PerfectMathTrialExpiresMay042026"
    }
  }
}

Claude Web

Go to Settings → MCP Servers → Add Server. Paste the server URL:

https://mcp.yggdrasilapi.com/DRASIL-PerfectMathTrialExpiresMay042026

Claude Code

Run this command in your terminal:

claude mcp add drasil-math https://mcp.yggdrasilapi.com/DRASIL-PerfectMathTrialExpiresMay042026

Test It

After adding the server, ask Claude any math problem. Drasil activates automatically. Try:

// Ask Claude:
A store sells 3 packs of pencils. Each pack has 12 pencils.
If 7 pencils break, how many working pencils remain?

Claude will call drasil_protocol, load the reasoning protocol, solve with exact arithmetic, and return a verified answer.

Available Tools

The MCP server exposes two tools that Claude can call:

Tool	Description	Auth Required
drasil_protocol	Loads the full Drasil math reasoning protocol (186 lines). Claude calls this before solving any math problem. The protocol is ephemeral — used once, then discarded.	Key in URL
drasil_status	Returns license status, version, tier, and benchmark results. Useful for checking if your key is active and what access level you have.	Key in URL

Authentication

The Drasil key is embedded in the MCP server URL. No per-request headers or tokens needed. Once the URL is configured, every tool call is automatically authenticated.

URL Format

https://mcp.yggdrasilapi.com/{YOUR_KEY}

Key Tiers

Tier	Format	Access	Duration
Public Trial	`DRASIL-PerfectMath...`	Full protocol	Expires May 4, 2026
Trial	`DRASIL-TRIAL-XXXXXXXX`	Full protocol	6 hours from first use
Dev	`DRASIL-DEV-XXXXXXXX`	Full protocol	Permanent
Master	`DRASIL-MASTER-XXXXXXXX`	Full protocol + admin	Permanent

How It Works

When Claude receives a math problem:

1. Tool call — Claude calls drasil_protocol via MCP
2. Key validation — The server checks your key against the license database
3. Protocol delivery — The full 186-line reasoning protocol is returned
4. Execution — Claude follows the protocol: parse, scene-log, compute, verify
5. Discard — After answering, the protocol is discarded. Nothing persists.

The protocol is ephemeral by design. It loads fresh for each problem and is never stored in conversation memory. This protects the methodology while giving Claude exact reasoning capabilities.

Protocol Phases

The Drasil protocol uses a four-phase reasoning engine:

Phase	Name	What It Does
1	Parse	Extracts all numerical entities, relationships, and targets. Classifies every sentence. Zero assumptions.
2	Scene Log	Builds an entity ledger. Every value tracked from initial state through all operations with a complete audit trail.
3	Compute	Vertical column arithmetic with explicit carry tracking. No approximation, no skipping, no shortcuts.
4	Verify	Inverse-checks every operation before committing. Sanity bounds applied. Answer confirmed only after full verification pass.

Benchmark Results

Tested against complete HuggingFace datasets. Every problem, every difficulty level.

Benchmark	Score	Details
GSM8K	1,319/1,319 (100%)	Full dataset. 5 annotation errors found and documented.
MATH-500	500/500 (100%)	All 5 difficulty levels including 74 Level 5 competition problems.
Arithmetic	100/100 (100%)	All operations cross-checked by Python.
Total	1,919/1,919 (100%)	Zero methodology errors.

API Reference

The MCP server also has a REST API for direct integration.

Base URL

https://api.yggdrasilapi.com

Endpoints

Method	Endpoint	Auth	Description
GET	/v1/status	Public	Service status, version, benchmark results
GET	/v1/skill	X-Drasil-Key	Full reasoning protocol (186 lines)
POST	/v1/trial	Public	Request a 6-hour trial key (requires email)

Example: Fetch Protocol

curl https://api.yggdrasilapi.com/v1/skill \
  -H "X-Drasil-Key: DRASIL-DEV-XXXXXXXX"

Example: Check Status

curl https://api.yggdrasilapi.com/v1/status

Troubleshooting

Claude doesn't call the tool

Make sure the MCP server is listed in your Claude settings. In Claude Desktop, check Settings → Developer → MCP Servers. The server should show as connected. Try asking a specific math question like "What is 847 * 293?"

Getting "Invalid key" error

Check that the full key is in the URL with no extra spaces or characters. Keys are case-sensitive and start with DRASIL-.

Trial expired

Trial keys last 6 hours from first use. The public trial key expires May 4, 2026. Visit support to request a new key or inquire about licensing.

"Protocol not provisioned" error

This means the server-side protocol content hasn't been loaded into the KV store. Contact support — this is a server-side issue, not a key issue.

Connection timeout

The MCP server runs on Cloudflare's global edge network. If you're experiencing timeouts, check your internet connection. The server responds in under 50ms under normal conditions.

Support

If you run into issues or have questions:

Submit a support ticket — we typically respond within 24 hours
Check your ticket status at yggdrasilapi.com/support

DocumentationDrasil MCP Server v1.2.1