Openeruka

openeruka

[](https://crates.io/crates/openeruka) [](https://docs.rs/openeruka) [](https://github.com/dirmacs/openeruka/actions) [](LICENSE)

The open-source knowledge state memory server for AI agents.

openeruka is a fully self-contained memory server that enforces the knowledge state invariant: Confirmed facts cannot be overwritten by Inferred guesses. Run it locally, connect eruka-mcp to it, and your AI agent gets grounded, protected memory. Ships as a single binary with SQLite bundled — production-ready in one command.

# Install the server binary
cargo install openeruka

# Start it
openeruka serve                  # default port 8080

# Connect Claude Code / Claude Desktop via eruka-mcp
# Default ERUKA_API_URL is http://localhost:8080 — no extra config needed

The knowledge state invariant

use openeruka::KnowledgeState;

// The core contract — enforced server-side, not advisory
assert!( KnowledgeState::Confirmed.can_overwrite(&KnowledgeState::Inferred));
assert!(!KnowledgeState::Inferred.can_overwrite(&KnowledgeState::Confirmed));

When your agent tries to overwrite a Confirmed fact with an Inferred guess, the server returns 409 Conflict. LLM hallucinations cannot corrupt verified knowledge. No other memory system enforces this.

Interaction surfaces

openeruka exposes three equivalent interfaces:

| Interface | Command | Use case | |---|---|---| | REST API | openeruka serve | Connect any HTTP client, agent, or openeruka-client | | MCP server | openeruka mcp | Claude Desktop, Claude Code, Cursor via eruka-mcp | | CLI | openeruka get/set | Quick reads and writes from the terminal |

All three share the same SQLite backend and enforce the same knowledge state rules.

Quick start

# Install
cargo install openeruka

# Start REST server (SQLite backend, default ./eruka.db)
openeruka serve

# Write a confirmed fact
curl -X POST http://localhost:8080/api/v1/context \
  -H "Content-Type: application/json" \
  -d '{"workspace_id":"my-project","path":"identity/company_name","value":"Acme Corp","knowledge_state":"CONFIRMED","confidence":1.0,"source":"user_input"}'

# Try to overwrite with an inferred guess — rejected with 409
curl -X POST http://localhost:8080/api/v1/context \
  -H "Content-Type: application/json" \
  -d '{"workspace_id":"my-project","path":"identity/company_name","value":"Acme AI Labs","knowledge_state":"INFERRED","confidence":0.7,"source":"agent_inference"}'
# → 409 Conflict: field is CONFIRMED, write has lower knowledge state

# Read it back — still the original
curl "http://localhost:8080/api/v1/context?workspace_id=my-project&path=identity/company_name"

Use as a library

[dependencies]
openeruka = { version = "0.2", default-features = false }
openeruka-client = "0.1"

// Embed SqliteContextStore in your own Rust agent
use openeruka::{SqliteContextStore, ContextStore, ErukaFieldWrite, KnowledgeState, SourceType};

let store = SqliteContextStore::open("./eruka.db").await?;

// Write enforces the invariant
store.write_field("my-ws", ErukaFieldWrite {
    path: "identity/name".to_string(),
    value: serde_json::json!("DIRMACS"),
    knowledge_state: KnowledgeState::Confirmed,
    confidence: 1.0,
    source: SourceType::UserInput,
}).await?;

openeruka vs eruka.dirmacs.com

eruka-mcp can connect to either:

# Local openeruka (OSS, SQLite, single-tenant)
ERUKA_API_URL=http://localhost:8080 eruka-mcp

# Managed Eruka (PostgreSQL, multi-tenant, enterprise features)
ERUKA_API_URL=https://eruka.dirmacs.com ERUKA_API_KEY=sk:your-key eruka-mcp

| | openeruka (OSS) | eruka.dirmacs.com | |---|---|---| | Knowledge state enforcement | ✅ | ✅ | | REST + MCP + CLI | ✅ | ✅ | | SQLite (local) | ✅ | — | | PostgreSQL (scalable) | — | ✅ | | Multi-tenancy | — | ✅ | | B6 quality scoring | — | ✅ | | Datalog inference | — | ✅ | | Gardener pipeline | — | ✅ | | SLA / HIPAA / SSO | — | ✅ |

DIRMACS ecosystem

• eruka-mcp — MCP client for openeruka and eruka.dirmacs.com
• ARES — multi-agent runtime that uses Eruka for context
• pawan — CLI coding agent with Eruka memory
• deagle — code intelligence engine
• DIRMACS — the company behind this stack

Docs

dirmacs.github.io/openeruka

License

MIT — see [LICENSE](LICENSE)

Source & license

This open-source MCP server is cataloged on AgentStack and links to its original source — we do not rehost the code.

• Author: dirmacs
• Source: dirmacs/openeruka
• License: MIT
• Homepage: https://dirmacs.github.io/openeruka/

Install and usage instructions live in the source repository linked above.