Remote Procedure Calls over Nostr

Published Nov 20, 2025

kind 22068kind 22609kind 21169

Remote Procedure Calls over Nostr

NRPC defines a Remote Procedure Call (RPC) mechanism over Nostr events. Requests and responses are expressed as signed events and routed via relays. This enables backend services to be hosted without requiring inbound network access, cloud infrastructure, or centralized API management.

Problems Addressed

Traditional backend services typically require:

A publicly reachable server (static IP, port forwarding, or tunneling).

Domain names and TLS termination.

Centralized API key or token management.

This specification removes those requirements by using Nostr’s event transport. Services can operate with only outbound relay connections, authentication is inherent in event signatures, and requests and responses can be processed asynchronously.

Specification

Event Kinds

Request Event: kind: 22068

Response Event: kind: 22069

Request Event (22068)

Author: Caller’s pubkey.

Tags:

["p", "<callee_pubkey>"] — target service identity.

["method", "<method_name>"] — method to invoke.

["param", "<key>", "<value>"] — optional, repeatable parameters.

Content: optional payload

Response Event (22069)

Author: Callee’s pubkey.

Tags:

["e", "<request_event_id>"] — ID of the request being answered.

["p", "<caller_pubkey>"] — recipient of this response.

["status", "<http_status_code>"] — HTTP-style status code.

On success:

["result", "<key>", "<value>"] — repeatable.

["result_json", "<json_string>"] — optional structured payload.

On error:

["error", "<http_status_code>", "<message>"]

Content: optional payload (e.g., JSON string).

Examples

Request Example

{
  "kind": 22068,
  "tags": [
    [
      "p",
      "62a904c9c0e4ac1e221dc91202ee3bd98f6fd2460b619d953921108adda1af72"
    ],
    [
      "method",
      "sendDM"
    ]
  ],
  "content": "",
  "created_at": 1758638576,
  "pubkey": "c21b1a6cdb247ccbd938dcb16b15a4fa382d00ffd7b12d5cbbad172a0cd4d170",
  "id": "aa05848fac18ecd4e0be17f4e041b808eb949963b03dd128ca7b9d610257639b",
  "sig": "8153860b5ddacceff0c89ff3d86c7e323f4e826f8415aa288d587c962ff7b209e40dace4199ff5edb21d69ab14f7f0d74328e36e48d06897d120418eaeec3e8b"
}

Response Example

RESPONSE EVENT {
  kind: 22069,
  pubkey: '62a904c9c0e4ac1e221dc91202ee3bd98f6fd2460b619d953921108adda1af72',
  created_at: 1758640291,
  tags: [
    [
      'e',
      'af955bdb56977df2e0acd43791377cfcf671e334d4a5d5859af810e3c6a5cff6'
    ],
    [
      'p',
      'c21b1a6cdb247ccbd938dcb16b15a4fa382d00ffd7b12d5cbbad172a0cd4d170'
    ],
    [ 'status', '200' ],
    [ 'result_json', '{}' ]
  ],
  content: '',
  id: 'ce1fa98bd61128beb2ba3f213086ece096eb75dc30b012d4bd2672f23415ae57',
  sig: '2647f1cad66d6a85752cbb1b07feb37077299c089bf5d1dbb79c0fd37b86ac54bbd09960d719c1b7afdcab103e148c30899b90d4367525dbb1be75f7c1c3de07',
  [Symbol(verified)]: true
}

Service Introspection

It is recommended for services to provide a special getMethods runtime introspection of the service’s available RPC calls. A client may invoke it at any time to discover supported methods, required parameters, possible results, and error conditions.

Request

A getMethods request is a standard Request Event (kind: 22068) with:

["p", "<callee_pubkey>"]
["method", "getMethods"]

No additional ["param", ...] tags are required.

Response

The callee returns a Response Event (kind: 22069) with status 200. Supported methods are described in repeated result tags using the following schema:

["result", "method", "<method_name>"]

["result", "param", "<param_name>", "<param_type>", "<required_flag>"]
["result", "return", "<field_name>", "<field_type>"]
["result", "error", "<status_code>", "<description>"]

Real World Examples

Request

{
  "kind": 22068,
  "pubkey": "65b078fb5f4183c0538f84321ff14c0b468ded7dd45ede80d84a2ffe3a9a44dc",
  "created_at": 1758686491,
  "tags": [
    [
      "p",
      "62a904c9c0e4ac1e221dc91202ee3bd98f6fd2460b619d953921108adda1af72"
    ],
    [
      "method",
      "getMethods"
    ]
  ],
  "content": "",
  "id": "d15fac11a463331f342e723fe312c992ba4ec53835b86ff3418c19932d6f5acc",
  "sig": "9a8b1d0733c75475110a1dba09d59167430949f24148ee16bb431ea672412d4195f758fe3eda882f6c90032f4bdc2856653c230836988d9bec72aa918039b39c"
}

Response

{
  "content": "",
  "created_at": 1758686639,
  "id": "fd333cfcfb364e5d7056a9b18e7e279b45b7abca4a12c4fb7497062e619dc330",
  "kind": 22069,
  "pubkey": "62a904c9c0e4ac1e221dc91202ee3bd98f6fd2460b619d953921108adda1af72",
  "sig": "6630d10fb5792b42aac7897119b94271d85e339bc7e34a39eedcfbe2ead9e283dd7919a8311d18bb79f2c829b5184dc789e19b5479b1933f1dbcf3a7756f3599",
  "tags": [
    [
      "e",
      "e1bcf745b55bebbe33ea5f9f8a22d7f0b9bb1bb365cd41b53d936dfd7fb28734"
    ],
    [
      "p",
      "4e74e8c9c9c0dee32331c2d0245542fa93bef155e9d0339e2a7fd1f86eed9c11"
    ],
    ["status", "200"],
    ["result", "method", "createReminder"],
    ["result", "param", "createReminder", "Time", "string", "required"],
    ["result", "param", "createReminder", "Text", "string", "required"],
    ["result", "param", "createReminder", "Date", "string", "required"],
    ["result", "returns", "createReminder", "reminder_id", "string"],
    ["result", "returns", "createReminder", "scheduled_at", "string"],
    ["result", "returns", "createReminder","text","string"],
    ["result", "returns", "createReminder", "owner", "string"],
    ["result", "error", "createReminder", "400", "time and text required"],
    ["result", "method","getMethods"],
    ["result", "method", "sendDM"]
  ]
}

Encrypted Requests and Responses

To provide end-to-end privacy and authenticated RPC over Nostr, NRPC requests and responses can be sent as rumors sealed by the sender, then giftwrapped for transport.

Event Kinds

Rumor Request: kind 68 (unsigned)

Rumor Response: kind 69 (unsigned)

Seal: kind 25

Wrap: kind 21169 (signed by an ephemeral key, NIP-59 style)

Flow

Caller creates a rumor request (kind 68).

Caller encrypts that rumor into the content of a seal event, and signs the seal with their real pubkey. The callee can later verify who it actually came from.

Encrypt the seal into a giftwrap (21169) using an ephemeral key.

Request giftwrap tags: ["p", "<callee_pubkey>"]

Callee decrypts giftwrap → verifies seal signature → extracts rumor → processes.

Callee builds a rumor response (69), seals it with their real pubkey, and publishes it inside a giftwrap (21169).

Response giftwrap tags: ["e", "<requestrumorid>"]

Example Response Event

{
  "kind": 21169,
  "content": "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",
  "pubkey": "51e431948eb9827328d087ad93b7235a0a8e552853a53101593fdbaa569c5f2d",
  "tags": [
    ["e", "d02b941a1ffdcf6c60d5100015805607020c651b784f3a795432c5bfa5b5d94d"]
  ],
  "created_at": 1758712092,
  "id": "6c41facfef2b90fd6531de04b64f53e1ccd688f2b2e25a2931878bd916fded13",
  "sig": "b6c0daf9607083dd921771812f7a0cb497dd35dc8c50c6cd338475ce63fa87a01397b0902df0682cbf914d5100545311ca70dd7befb6ea4b546d90331fba960a"
}

Discover of Servers

npubs that listen on relays for nrpc request and want to advertise publicly should add a t-tag, with "nrpc_server" on their kind-0, to make their services searchable.