eruka-mcp

MCP (Model Context Protocol) server for Eruka — anti-hallucination context memory for AI agents.

What is Eruka?

Eruka is a knowledge engine that tracks what AI agents know, what they don't know, and what they should never fabricate. It provides:

• 4 Knowledge States: CONFIRMED, INFERRED, UNCERTAIN, UNKNOWN
• Gap Detection: identifies missing information before generation
• Constraint Injection: "DO NOT FABRICATE" directives for LLM prompts
• Knowledge Decay: confidence degrades over time, facts become UNCERTAIN
• Quality Scoring: 6-layer hallucination detection pipeline

Install

cargo install eruka-mcp

Or build from source:

git clone https://github.com/dirmacs/eruka-mcp
cd eruka-mcp
cargo build --release

Setup

eruka-mcp works with two backends:

Local mode — openeruka

Run the open-source Eruka server locally — single binary, SQLite backend, zero infrastructure.

# 1. Install the local server
cargo install openeruka-server   # installs the `openeruka` binary

# 2. Start it
openeruka serve  # runs at http://localhost:8080

# 3. Run eruka-mcp — connects to localhost:8080 by default
eruka-mcp

Full docs: dirmacs.github.io/openeruka

Managed mode — eruka.dirmacs.com

1. Sign up at eruka.dirmacs.com
2. Create a service key (Settings > API Keys)
3. Set your key:

export ERUKA_API_URL=https://eruka.dirmacs.com
export ERUKA_API_KEY=eruka_sk_...

Usage

Claude Desktop

Local mode (openeruka — runs locally, no service required):

{
  "mcpServers": {
    "eruka": {
      "command": "eruka-mcp"
    }
  }
}

Managed mode (eruka.dirmacs.com):

{
  "mcpServers": {
    "eruka": {
      "command": "eruka-mcp",
      "env": {
        "ERUKA_API_URL": "https://eruka.dirmacs.com",
        "ERUKA_API_KEY": "eruka_sk_..."
      }
    }
  }
}

Claude Code

Local mode:

claude mcp add eruka eruka-mcp

Managed mode:

claude mcp add eruka eruka-mcp \
  -e ERUKA_API_URL=https://eruka.dirmacs.com \
  -e ERUKA_API_KEY=eruka_sk_...

Streamable HTTP Transport (remote MCP)

Run as a remote MCP server for claude.ai web, Cursor, or any HTTP-capable MCP client:

eruka-mcp --transport sse --port 8080

This starts a Streamable HTTP server (MCP spec 2025-03-26) at http://localhost:8080/mcp:

• POST /mcp — JSON-RPC 2.0 requests (initialize, tools/list, tools/call)
• GET /mcp — SSE notification stream
• Session management via Mcp-Session-Id header

Claude.ai Web

Use the hosted endpoint at https://eruka.dirmacs.com/mcp:

1. Go to claude.ai → Settings → Connectors → Add custom connector
2. Enter URL: https://eruka.dirmacs.com/mcp
3. Authenticate with your Eruka credentials (OAuth)
4. All 18 tools are automatically available

Direct HTTP Test

curl -X POST http://localhost:8080/mcp \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","method":"tools/list","id":1}'

Tools

Tool	Description	Tier
eruka_get_context	Retrieve fields by schema path	Free
eruka_search_context	Semantic search across all context	Free
eruka_get_completeness	Completeness score with per-category breakdown	Free
eruka_get_gaps	List knowledge gaps sorted by impact	Free
eruka_write_context	Write or update a field	Free
eruka_get_voice	Retrieve brand voice guidelines	Free
eruka_detect_gaps	Run gap detection for a task type	Free
eruka_get_constraint	Generate anti-hallucination constraint text	Pro
eruka_get_related	Traverse the knowledge graph	Free
eruka_add_relationship	Create typed edges in the knowledge graph	Free
eruka_get_context_compressed	Token-efficient compressed context	Free
eruka_get_context_cached	Diff-based caching with session tracking (20-30% token savings)	Free
eruka_prefetch	Agent lifecycle: pre-fetch context for current turn	Free
eruka_sync_turn	Persist conversation turns to context store	Free
eruka_on_pre_compress	Save insights before context window compression	Free
eruka_export_context	Export all context as portable JSON bundle	Free
eruka_query_temporal	Query context at a point in time	Pro
eruka_research_gap	Auto-research and fill knowledge gaps	Pro

CLI Alias

For shorter commands, add an alias:

alias eruka='eruka-mcp'
# Then: eruka get "*", eruka write ..., eruka health

CLI Commands

eruka-mcp works as both an MCP server AND a standalone CLI tool. Without a subcommand, it runs as an MCP server (backward compatible).

# Read all context
eruka-mcp get "*"

# Read a specific field
eruka-mcp get "identity/company_name"

# Write a field
eruka-mcp write "identity/mission" "Build anti-hallucination infrastructure"

# Write with custom confidence and source
eruka-mcp write "market/tam" '$4.2B' --confidence 0.7 --source agent_inference

# Search
eruka-mcp search "revenue"

# Completeness report
eruka-mcp completeness

# Knowledge gaps
eruka-mcp gaps

# Health check
eruka-mcp health

# JSON output (for scripting)
eruka-mcp get "*" --format json
eruka-mcp completeness --format json

All CLI commands use the same ERUKA_API_KEY and ERUKA_API_URL environment variables as the MCP server.

Environment Variables

Variable	Description	Default
ERUKA_API_URL	Backend URL — local openeruka or managed service	http://localhost:8080
ERUKA_API_KEY	Service key — "local" for openeruka, eruka_sk_... for managed	local

CLI Reference

eruka-mcp [OPTIONS] [COMMAND]

Commands:
  get             Read context fields
  write           Write a context field
  search          Search context
  completeness    Show completeness report
  gaps            List knowledge gaps
  health          Check API health

Options:
      --api-url <URL>        Eruka API URL [env: ERUKA_API_URL]
      --api-key <KEY>        Service key [env: ERUKA_API_KEY]
      --tier <TIER>          Tier override [default: free]
      --transport <MODE>     stdio or sse [default: stdio]
      --port <PORT>          SSE port [default: 8080]
      --format <FMT>         Output: text or json [default: text]
      --debug                Debug logging

License

MIT