| name | overview |
| description | Understand ContextVM protocol fundamentals, architecture, and core concepts. Use when users need to learn about ContextVM basics, how it bridges MCP with Nostr, protocol design principles, event kinds, or the relationship between MCP and Nostr in decentralized communication. |
ContextVM Overview
ContextVM (Context Virtual Machine) is a protocol that bridges the Model Context Protocol (MCP) with the Nostr network, enabling decentralized communication between MCP servers and clients.
Core Concept
ContextVM operates as a transport layer for MCP, using Nostr's relay network as the communication mechanism while preserving MCP's JSON-RPC semantics.
┌─────────────────────────────────────────────────────────────┐
│ MCP Application Layer │
│ (Tools, Resources, Prompts, Sampling) │
├─────────────────────────────────────────────────────────────┤
│ ContextVM Transport Layer │
│ (Nostr events, Encryption, Public Key Cryptography) │
├─────────────────────────────────────────────────────────────┤
│ Nostr Relay Network │
│ (wss://relay.contextvm.org, etc.) │
└─────────────────────────────────────────────────────────────┘
Key Features
- Decentralized Communication: No central servers required; use Nostr's distributed relay network
- Security First: Leverages Nostr's cryptographic primitives for verification and authorization
- Public Key Identity: Servers and clients identified by Nostr public keys
- Optional Encryption: End-to-end encryption via NIP-44 gift wrapping
- Server Discovery: Public server announcements via replaceable events
Protocol Architecture
Three-Layer Design
- Transport Layer: Nostr events and relays
- Message Layer: JSON-RPC MCP messages embedded in event content
- Metadata Layer: Nostr event tags for addressing and correlation
Main Actors
| Actor | Role | Identification |
|---|
| Servers | Expose MCP capabilities | Public key + relays |
| Clients | Consume server capabilities | Public key |
| Relays | Propagate messages | URL (wss://...) |
Event Kinds
ContextVM uses these Nostr event kinds:
| Kind | Purpose | Persistence |
|---|
25910 | All ContextVM messages (ephemeral) | Not stored by relays |
11316 | Server announcement | Replaceable |
11317 | Tools list | Replaceable |
11318 | Resources list | Replaceable |
11319 | Resource templates list | Replaceable |
11320 | Prompts list | Replaceable |
1059 | Gift wrap (encrypted messages) | Ephemeral |
Message Flow
Connection Process
- Discovery: Client discovers server via public key or relay queries
- Initialization: Standard MCP handshake over Nostr
- Operation: Client calls tools/lists resources via kind 25910 events
- Termination: Connection closes when either party disconnects
Event Structure
{
"kind": 25910,
"pubkey": "<sender-public-key>",
"content": "{\"jsonrpc\":\"2.0\",...}",
"tags": [
["p", "<recipient-public-key>"],
["e", "<correlation-event-id>"]
]
}
Security Model
Public Key Cryptography
- All messages cryptographically signed
- Server identity = public key (portable across relays)
- Client authorization via public key whitelisting
Encryption (CEP-4)
- Optional NIP-44 encryption via gift wrap (kind 1059)
- Negotiated during initialization
- Servers advertise support via
support_encryption tag
The Nostr Way
ContextVM follows the same core pattern as other Nostr-based RPC systems (like DVMs): publish a signed request event, listen for a correlated response. The difference is in the message structure—CVM uses JSON-RPC via MCP rather than provider-specific payloads.
To understand this foundation:
Reference Materials
For detailed specifications, see:
Ecosystem Navigation (what to use when)
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