Nostr Signer

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

Approve Nostr signatures with your own browser signer without exposing a private key.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "Nostr Signer": {
      "url": "https://signer.frontiercrown.com/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (17)

• get_setup_url read-only

  Return the loopback-only page used to connect a NIP-07 browser extension or an advanced NIP-46 signer.

  Hints: read-only yes · destructive no · idempotent not declared · open-world no

• get_signer_status read-only

  Check whether a user-controlled NIP-07 or NIP-46 signer is connected.

  Hints: read-only yes · destructive no · idempotent not declared · open-world no

• begin_nostrconnect_pairing

  Advanced fallback: create a nostrconnect:// URI for the user to scan or open in a remote signer. Never accepts an nsec.

  Parameters:

  • relays — array

  Hints: read-only no · destructive no · idempotent not declared · open-world yes

• connect_bunker

  Connect a bunker:// URI only when the user knowingly supplied it. Prefer the local setup page so connection secrets are not placed in chat. Never accepts an nsec.

  Parameters:

  • connection_uri (required) — string

  Hints: read-only no · destructive no · idempotent not declared · open-world yes

• get_public_key read-only

  Return the public key exposed by the currently paired signer.

  Hints: read-only yes · destructive no · idempotent not declared · open-world no

• prepare_note read-only

  Prepare and bind an exact unsigned kind:1 note for user review. This does not sign or publish.

  Parameters:

  • content (required) — string

  Hints: read-only yes · destructive no · idempotent not declared · open-world no

• prepare_event read-only

  Validate and bind an exact unsigned Nostr event for user review. This does not sign or publish. Show the user every field before requesting a signature.

  Parameters:

  • event (required) — object

  Hints: read-only yes · destructive no · idempotent not declared · open-world no

• sign_event

  Ask the paired signer to approve and sign the exact event bound to a fresh intent. Requires explicit user intent and never publishes.

  Parameters:

  • intent_id (required) — string
  • confirm_signature (required) — boolean — Must be true only after the user explicitly approved this action.

  Hints: read-only no · destructive no · idempotent not declared · open-world yes

• publish_event destructive

  Publish a previously verified signed event to configured relays. Requires separate explicit user intent.

  Parameters:

  • intent_id (required) — string
  • confirm_publish (required) — boolean — Must be true only after the user explicitly approved this action.
  • relays — array

  Hints: read-only no · destructive yes · idempotent not declared · open-world yes

• query_events read-only

  Read a bounded set of verified public profile or note events from selected relays.

  Parameters:

  • kinds — array
  • limit — integer
  • since — integer
  • relays — array
  • authors — array

  Hints: read-only yes · destructive no · idempotent not declared · open-world yes

• disconnect_signer destructive

  Forget the in-memory signer session and all prepared events.

  Parameters:

  • confirm_disconnect (required) — boolean — Must be true only after the user explicitly approved this action.

  Hints: read-only no · destructive yes · idempotent not declared · open-world no

• get_grynvault_account_dashboard read-only

  Read the connected Nostr identity's Grynvault supporter, payment, and NIP-05 dashboard using a short-lived signed authorization. This does not create an invoice or change settlement.

  Parameters:

  • confirm_account_access (required) — boolean — Must be true only after the user approved signing a read-only Grynvault account request.

  Hints: read-only yes · destructive no · idempotent not declared · open-world yes

• approve_grynvault_browser_handoff

  Sign a short-lived, read-only Grynvault account handoff code so the browser tab that created it can receive its own dashboard. This does not create an invoice, publish a Nostr event, change settlement, or grant wallet custody.

  Parameters:

  • code (required) — string — The one-time code displayed by the Grynvault portal, for example ABCD-EFGH-JKLM.
  • confirm_browser_sign_in (required) — boolean — Must be true only after the user asked to sign the displayed Grynvault browser code.

  Hints: read-only no · destructive no · idempotent not declared · open-world yes

• prepare_grynvault_supporter_invoice read-only

  Prepare an exact, short-lived signed-authorization request for a one-time donation of 21 to 1,000,000 sats or the fixed 2,100-sat 30-day membership. Does not sign, create, pay, or settle an invoice.

  Parameters:

  • plan (required) — string
  • donation_sats — integer

  Hints: read-only yes · destructive no · idempotent not declared · open-world yes

• create_grynvault_supporter_invoice

  After separate explicit user confirmation, sign the prepared authorization and create exactly one pending Grynvault supporter invoice. Does not pay it and never treats a redirect as settlement.

  Parameters:

  • operation_id (required) — string
  • confirm_invoice_creation (required) — boolean — Must be true only after the user explicitly approved this action.

  Hints: read-only no · destructive no · idempotent not declared · open-world yes

• prepare_grynvault_nip05_invoice read-only

  Check and normalize a [email protected] identifier, then prepare its exact 2,000-sat invoice authorization. Does not sign, reserve the name, create, pay, or settle an invoice.

  Parameters:

  • name (required) — string

  Hints: read-only yes · destructive no · idempotent not declared · open-world yes

• create_grynvault_nip05_invoice

  After separate explicit user confirmation, sign the prepared authorization and create exactly one pending 2,000-sat [email protected] invoice. Does not pay, settle, activate, or prove identity.

  Parameters:

  • operation_id (required) — string
  • confirm_invoice_creation (required) — boolean — Must be true only after the user explicitly approved this action.

  Hints: read-only no · destructive no · idempotent not declared · open-world yes

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