From 5c03ff3e29d8b59b6cd7e7cd477fe2172fa21826 Mon Sep 17 00:00:00 2001
From: Jon Staab <shtaab@gmail.com>
Date: Mon, 13 Oct 2025 11:20:01 -0700
Subject: [PATCH] Pass pubkey to nip 55 signer to avoid mixing up sessions

---
 docs/signer/nip-55.md                | 83 ++--------------------------
 packages/app/src/session.ts          |  2 +-
 packages/lib/src/Tools.ts            |  2 +-
 packages/signer/src/signers/nip55.ts | 13 ++++-
 4 files changed, 16 insertions(+), 84 deletions(-)

diff --git a/docs/signer/nip-55.md b/docs/signer/nip-55.md
index 9191635..7b05062 100644
--- a/docs/signer/nip-55.md
+++ b/docs/signer/nip-55.md
@@ -18,7 +18,8 @@ import { Nip55Signer, getNip55 } from '@welshman/signer'
 // Check for available signing apps
 const apps = await getNip55()
 if (apps.length > 0) {
-  const signer = new Nip55Signer(apps[0].packageName)
+  const optionalSavedPubkey = localStorage.getItem('my-saved-pubkey')
+  const signer = new Nip55Signer(apps[0].packageName, optionalSavedPubkey)
 }
 ```
 
@@ -40,28 +41,11 @@ interface AppInfo {
 ### Constructor
 
 ```typescript
-constructor(packageName: string)
+constructor(packageName: string, publicKey?: string)
 ```
 Creates a new signer instance that will communicate with the specified native app.
 - `packageName`: The package identifier of the native signing app
-
-### ISigner implementation
-
-The `Nip55Signer` class implements the [`ISigner`](/signer/) interface
-
-```typescript
-class Nip55Signer implements ISigner {
-  // Constructor
-  constructor(private secret: string)
-
-  // ISigner implementation
-  sign: SignWithOptions
-  getPubkey: () => Promise<string>
-  nip04: { encrypt, decrypt }
-  nip44: { encrypt, decrypt }
-}
-```
-
+- `publicKey`: optional user pubkey. Recommended for resuming existing signer sessions when the signer is managing multiple user accounts.
 
 ## Complete Example
 
@@ -104,62 +88,3 @@ async function example() {
   }
 }
 ```
-
-## Implementation Details
-
-### Request Serialization
-
-The signer implements a lock mechanism to prevent concurrent requests:
-
-```typescript
-class Nip55Signer implements ISigner {
-  #lock = Promise.resolve()
-  #plugin = NostrSignerPlugin
-  #packageName: string
-  #packageNameSet = false
-
-  #then = async <T>(f: (signer: typeof NostrSignerPlugin) => Promise<T>) => {
-    const promise = this.#lock.then(async () => {
-      if (!this.#packageNameSet) {
-        await this.#initialize()
-      }
-      return f(this.#plugin)
-    })
-
-    this.#lock = promise.then(() => Promise.resolve())
-
-    return promise
-  }
-}
-```
-
-### Public Key Caching
-
-The signer caches the public key to minimize native app interactions:
-
-```typescript
-class Nip55Signer {
-  #npub?: string
-  #publicKey?: string
-
-  getPubkey = async (): Promise<string> => {
-    return this.#then(async signer => {
-      if (!this.#publicKey || !this.#npub) {
-        const {npub} = await signer.getPublicKey()
-        this.#npub = npub
-        const {data} = decode(npub)
-        this.#publicKey = data as string
-      }
-      return this.#publicKey
-    })
-  }
-}
-```
-
-
-## Platform Support
-
-- iOS: Requires compatible signing app
-- Android: Requires compatible signing app
-- Operations availability depends on native app implementation
-- Some features might be platform-specific
diff --git a/packages/app/src/session.ts b/packages/app/src/session.ts
index aefd9ba..906fb3f 100644
--- a/packages/app/src/session.ts
+++ b/packages/app/src/session.ts
@@ -239,7 +239,7 @@ export const getSigner = cached({
   getValue: ([session]: [Session | undefined]) => {
     if (isNip07Session(session)) return wrapSigner(new Nip07Signer())
     if (isNip01Session(session)) return wrapSigner(new Nip01Signer(session.secret))
-    if (isNip55Session(session)) return wrapSigner(new Nip55Signer(session.signer))
+    if (isNip55Session(session)) return wrapSigner(new Nip55Signer(session.signer, session.pubkey))
     if (isNip46Session(session)) {
       const {
         secret: clientSecret,
diff --git a/packages/lib/src/Tools.ts b/packages/lib/src/Tools.ts
index 19453ce..6dc0fd3 100644
--- a/packages/lib/src/Tools.ts
+++ b/packages/lib/src/Tools.ts
@@ -622,7 +622,7 @@ export const sortBy = <T>(f: (x: T) => any, xs: T[]) =>
  * @param xs - Array to group
  * @returns Map of groups
  */
-export const groupBy = <T, K>(f: (x: T) => K, xs: T[]) => {
+export const groupBy = <T, K>(f: (x: T) => K, xs: Iterable<T>) => {
   const r = new Map<K, T[]>()
 
   for (const x of xs) {
diff --git a/packages/signer/src/signers/nip55.ts b/packages/signer/src/signers/nip55.ts
index 1a6089b..209b7b9 100644
--- a/packages/signer/src/signers/nip55.ts
+++ b/packages/signer/src/signers/nip55.ts
@@ -1,5 +1,5 @@
 import {NostrSignerPlugin, AppInfo} from "nostr-signer-capacitor-plugin"
-import {decode} from "nostr-tools/nip19"
+import * as nip19 from "nostr-tools/nip19"
 import {SignedEvent, StampedEvent} from "@welshman/util"
 import {hash, own, signWithOptions, SignOptions, ISigner} from "../util.js"
 
@@ -16,8 +16,14 @@ export class Nip55Signer implements ISigner {
   #npub?: string
   #publicKey?: string
 
-  constructor(packageName: string) {
+  constructor(packageName: string, publicKey?: string) {
     this.#packageName = packageName
+
+    if (publicKey) {
+      this.#publicKey = publicKey
+      this.#npub = nip19.npubEncode(publicKey)
+    }
+
     this.#initialize()
   }
 
@@ -53,8 +59,9 @@ export class Nip55Signer implements ISigner {
       if (!this.#publicKey || !this.#npub) {
         try {
           const {npub} = await signer.getPublicKey()
+          const {data} = nip19.decode(npub)
+
           this.#npub = npub
-          const {data} = decode(npub)
           this.#publicKey = data as string
         } catch (error) {
           throw new Error("Failed to get public key")