# Context Engine

> Open-source platform for deterministic, token-aware context selection for AI agents and LLMs

- **Type:** MCP server
- **Install:** `agentstack add mcp-contextenginehq-context-engine`
- **Verified:** Yes — security-reviewed for prompt injection and unsafe behavior
- **Seller:** [contextenginehq](https://agentstack.voostack.com/s/contextenginehq)
- **Installs:** 0
- **Category:** [AI & ML](https://agentstack.voostack.com/c/ai-and-ml)
- **Latest version:** 0.1.0
- **License:** Apache-2.0
- **Upstream author:** [contextenginehq](https://github.com/contextenginehq)
- **Source:** https://github.com/contextenginehq/context-engine

## Install

```sh
agentstack add mcp-contextenginehq-context-engine
```

Requires the [AgentStack CLI](https://agentstack.voostack.com/docs/cli). Works with Claude Code, Cursor, and any MCP-compatible agent.

## About

# Context Engine

The Context Engine is an open-source platform for deterministic, token-aware context selection. It helps AI agents and LLM applications retrieve exactly the right context within budget constraints.

## Architecture

```
context-engine (you are here)
├── context-core        — Core library: scoring, selection, caching
├── context-cli         — CLI: build, resolve, inspect commands
├── context-mcp-server  — MCP server: JSON-RPC 2.0 stdio transport
├── context-compat      — Compatibility test harness
├── context-specs       — Protocol specifications and ADRs
├── context-docs        — Documentation site
├── context-examples    — Example integrations
├── context-sdk-js      — JavaScript/TypeScript SDK (planned)
└── context-sdk-python  — Python SDK (planned)
```

## Quick Start

```bash
# Build the CLI
git clone https://github.com/contextenginehq/context-cli.git
cd context-cli
cargo build --release

# Build a context cache from your documents
./target/release/context build --sources ./docs --cache ./my-cache

# Resolve context for a query within a token budget
./target/release/context resolve --cache ./my-cache --query "deployment" --budget 4000
```

## MCP Integration

The Context Engine exposes its capabilities through the [Model Context Protocol](https://modelcontextprotocol.io/), making it compatible with any MCP-aware AI agent.

```bash
# Start the MCP server
git clone https://github.com/contextenginehq/context-mcp-server.git
cd context-mcp-server
cargo build --release
./target/release/mcp-context-server --cache-root ./caches
```

## Key Properties

- **Deterministic**: Same input always produces identical output, byte-for-byte
- **Token-aware**: Respects token budgets for LLM context windows
- **Versioned caches**: Backward-compatible cache format with version tracking
- **Frozen contracts**: v0 output schemas, error codes, and behaviors are locked

## Repositories

| Repository | Description | Status |
|-----------|-------------|--------|
| [context-core](https://github.com/contextenginehq/context-core) | Core scoring and selection library | v0.1.0 |
| [context-cli](https://github.com/contextenginehq/context-cli) | Command-line interface | v0.1.0 |
| [context-mcp-server](https://github.com/contextenginehq/context-mcp-server) | MCP server | v0.1.0 |
| [context-compat](https://github.com/contextenginehq/context-compat) | Compatibility test harness | v0.1.0 |
| [context-specs](https://github.com/contextenginehq/context-specs) | Protocol specifications | v0 |
| [context-docs](https://github.com/contextenginehq/context-docs) | Documentation | Active |
| [context-examples](https://github.com/contextenginehq/context-examples) | Example integrations | Active |
| [context-sdk-js](https://github.com/contextenginehq/context-sdk-js) | JavaScript SDK | Planned |
| [context-sdk-python](https://github.com/contextenginehq/context-sdk-python) | Python SDK | Planned |

## License

Apache-2.0

---

"Context Engine" is a trademark of Context Engine Contributors. The software is open source under the [Apache License 2.0](LICENSE). The trademark is not licensed for use by third parties to market competing products or services without prior written permission.

## Source & license

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

- **Author:** [contextenginehq](https://github.com/contextenginehq)
- **Source:** [contextenginehq/context-engine](https://github.com/contextenginehq/context-engine)
- **License:** Apache-2.0

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

## Pricing

- **Free** — Free

## Security capabilities

Automated source analysis of v0.1.0 — what this tool can access:

- **Network access:** no
- **Filesystem access:** no
- **Shell / process execution:** no
- **Environment & secrets:** no
- **Dynamic code execution:** no

*"Yes" means the capability is present in the source — more access means more to trust, not that it is unsafe.*


## Versions

- **0.1.0** — security scan: passed — Imported from the upstream source.

## Links

- Listing page: https://agentstack.voostack.com/l/mcp-contextenginehq-context-engine
- Seller: https://agentstack.voostack.com/s/contextenginehq
- Browse the marketplace: https://agentstack.voostack.com/browse

---
Listed on AgentStack — the marketplace for AI agent skills and MCP servers. Every listing is security-reviewed. Creators keep 70%.