Nostr Signer

by signer.frontiercrown.com · remote · no sign-in to list tools · v0.4.0 · published by com.frontiercrown.signer

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

Deletes · 2Changes · 9

Compare Registry entry

17 tools: 2 can delete or cancel things, 9 change things and 6 only read.

Scanned Oct 21, 2026

Deletes or cancels2Claude Code: deny: see these tools
Can't be undone0Claude Code: ask
Changes things9Claude Code: ask: see these tools
Only reads6Claude Code: allow: see these tools

No check matched anything in the tool definitions. No finding is not a safety guarantee. How the checks work.

claude mcp add --transport http nostr-signer https://signer.frontiercrown.com/mcp

Tools

Open a tool for its reasons and full description. Descriptions are the publisher's own words, shown as they are.

17 tools

Deletes or cancels 2Removes, cancels or revokes something.Claude Code: deny

disconnect_signerForget the in-memory signer session and all prepared events.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it destructive (destructiveHint: true).
Description, as the server wrote it
Forget the in-memory signer session and all prepared events.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: true
- openWorldHint: false
publish_eventPublish a previously verified signed event to configured relays.No findings
Why it is in this group
- The name "publish_event" says "publish": a word for a change that another call does not undo.
- The server marks it destructive (destructiveHint: true).
Description, as the server wrote it
Publish a previously verified signed event to configured relays. Requires separate explicit user intent.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: true
- openWorldHint: true

Changes things 9Creates or changes something that can be changed back.Claude Code: ask

approve_grynvault_browser_handoffSign a short-lived, read-only Grynvault account handoff code so the browser tab that created it can receive its own dashboard.No findings
Why it is in this group
- The name "approve_grynvault_browser_handoff" says "approve": a word for a change.
- The input takes a statement or command to run (input.code), which can change anything it can reach.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- openWorldHint: true
begin_nostrconnect_pairingAdvanced fallback: create a nostrconnect:// URI for the user to scan or open in a remote signer.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Advanced fallback: create a nostrconnect:// URI for the user to scan or open in a remote signer. Never accepts an nsec.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- openWorldHint: true
connect_bunkerConnect a bunker:// URI only when the user knowingly supplied it.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- openWorldHint: true
create_grynvault_nip05_invoiceAfter separate explicit user confirmation, sign the prepared authorization and create exactly one pending 2,000-sat name@frontiercrown.com invoice.No findings
Why it is in this group
- The name "create_grynvault_nip05_invoice" says "create": a word for a change.
Description, as the server wrote it
After separate explicit user confirmation, sign the prepared authorization and create exactly one pending 2,000-sat name@frontiercrown.com invoice. Does not pay, settle, activate, or prove identity.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- openWorldHint: true
create_grynvault_supporter_invoiceAfter separate explicit user confirmation, sign the prepared authorization and create exactly one pending Grynvault supporter invoice.No findings
Why it is in this group
- The name "create_grynvault_supporter_invoice" says "create": a word for a change.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- openWorldHint: true
prepare_grynvault_nip05_invoiceCheck and normalize a name@frontiercrown.com identifier, then prepare its exact 2,000-sat invoice authorization.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
Check and normalize a name@frontiercrown.com identifier, then prepare its exact 2,000-sat invoice authorization. Does not sign, reserve the name, create, pay, or settle an invoice.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: true
prepare_grynvault_supporter_invoicePrepare 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.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: true
prepare_notePrepare and bind an exact unsigned kind:1 note for user review.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
Description, as the server wrote it
Prepare and bind an exact unsigned kind:1 note for user review. This does not sign or publish.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
sign_eventAsk the paired signer to approve and sign the exact event bound to a fresh intent.No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it
Ask the paired signer to approve and sign the exact event bound to a fresh intent. Requires explicit user intent and never publishes.
Annotations the server declares
- readOnlyHint: false
- destructiveHint: false
- openWorldHint: true

Only reads 6Looks things up and changes nothing.Claude Code: allow

get_grynvault_account_dashboardRead the connected Nostr identity's Grynvault supporter, payment, and NIP-05 dashboard using a short-lived signed authorization.No findings
Why it is in this group
- The name "get_grynvault_account_dashboard" says "get": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: true
get_public_keyReturn the public key exposed by the currently paired signer.No findings
Why it is in this group
- The name "get_public_key" says "get": a word for reading.
Description, as the server wrote it
Return the public key exposed by the currently paired signer.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
get_setup_urlReturn the loopback-only page used to connect a NIP-07 browser extension or an advanced NIP-46 signer.No findings
Why it is in this group
- The name "get_setup_url" says "get": a word for reading.
Description, as the server wrote it
Return the loopback-only page used to connect a NIP-07 browser extension or an advanced NIP-46 signer.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
get_signer_statusCheck whether a user-controlled NIP-07 or NIP-46 signer is connected.No findings
Why it is in this group
- The name "get_signer_status" says "get": a word for reading.
Description, as the server wrote it
Check whether a user-controlled NIP-07 or NIP-46 signer is connected.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
prepare_eventValidate and bind an exact unsigned Nostr event for user review.No findings
Why it is in this group
- The description's first verb is "validate": a word for reading.
Description, as the server wrote it
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.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: false
query_eventsRead a bounded set of verified public profile or note events from selected relays.No findings
Why it is in this group
- The name "query_events" says "query": a word for reading.
Description, as the server wrote it
Read a bounded set of verified public profile or note events from selected relays.
Annotations the server declares
- readOnlyHint: true
- destructiveHint: false
- openWorldHint: true

This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.

Install

Pinned to version 0.4.0. Values in angle brackets are yours to fill in.

claude mcp add --transport http nostr-signer https://signer.frontiercrown.com/mcp

Run in a terminal.

Claude Code permissions

Allow the reads, ask before a change, deny the deletes. Paste into .claude/settings.json.

.claude/settings.json

{
  "permissions": {
    "allow": [
      "mcp__nostr-signer__get_setup_url",
      "mcp__nostr-signer__get_signer_status",
      "mcp__nostr-signer__get_public_key",
      "mcp__nostr-signer__prepare_event",
      "mcp__nostr-signer__query_events",
      "mcp__nostr-signer__get_grynvault_account_dashboard"
    ],
    "ask": [
      "mcp__nostr-signer__begin_nostrconnect_pairing",
      "mcp__nostr-signer__connect_bunker",
      "mcp__nostr-signer__prepare_note",
      "mcp__nostr-signer__sign_event",
      "mcp__nostr-signer__approve_grynvault_browser_handoff",
      "mcp__nostr-signer__prepare_grynvault_supporter_invoice",
      "mcp__nostr-signer__create_grynvault_supporter_invoice",
      "mcp__nostr-signer__prepare_grynvault_nip05_invoice",
      "mcp__nostr-signer__create_grynvault_nip05_invoice"
    ],
    "deny": [
      "mcp__nostr-signer__publish_event",
      "mcp__nostr-signer__disconnect_signer"
    ]
  }
}

Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. It assumes the server is installed as nostr-signer. Review it before you use it.

Keep track

Get told when this server's tools change: a new tool, a new description, a new class.

https://anlyon.dev/servers/com.frontiercrown.signer/nostr-signer/changes.xml

An Atom feed. Works in any feed reader or Slack's RSS app.

Anlyon alternative

11 of these tools change something. Run those as governed actions.

Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.

Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.

Import an OpenAPI spec →

Compare with other servers for the same product.

Source: MCP Registry · repository. Synced Oct 21, 2026, 17:55 UTC.

For agents: Markdown · JSON · report this listing