Sidecar | A Classy Nostr Signer

A multi-account NIP-07 Nostr signer with a built-in Lightning wallet, in your browser sidebar.

Sidecar lives in your browser's side panel and hands every Nostr web app a secure window.nostr to sign in with, so you never paste your nsec into a website again. Your keys stay on your device, encrypted behind a PIN. It's a companion to your favorite Nostr client, not a replacement: sign, post, and zap in a tap, then jump right back to the app you love. 🔑 Your keys, your control Full NIP-07 signer: getPublicKey, signEvent, NIP-04 and NIP-44 encrypt/decrypt, and your relay list. Private keys are encrypted at rest (PBKDF2 to AES-GCM via WebCrypto), never stored in plaintext, never transmitted off your device. PIN-protected with automatic re-lock, and a warning before signing anything that would wipe your follows, mutes, or profile. Multiple accounts. Store as many keys as you like, switch the active one in a click, drag to reorder. Each site stays pinned to the account it logged in with, so there's no identity mix-up. Per-site permissions with a prompt that previews exactly what you're signing. Relay sign-in (NIP-42) is answered for your own relays, for reading as well as posting, so relays that gate reads stop coming back empty. Recent activity records what each signature actually was, and any row that signed an event opens it in your client, so the log can be checked rather than taken on trust. 📄 Backups that survive the browser A printable backup sheet for a new key, styled as an old-fashioned telegram: the nsec as text you can copy and as a QR you can scan back in, plus a serial to tell sheets apart. A locked second page carries the key as a password-encrypted secret that passes for a masquerade invitation. Import by photo, PDF, clipboard image, or live camera scan. All generated locally, nothing uploaded. One encrypted vault export covers accounts, wallets, and settings, and restore shows exactly what it will replace. 👤 Your profile, your way View and edit your profile, with the bio editor opening as tall as your bio. Edit and publish your outbox relays (NIP-65) right from your profile. An account overview drawer: following count, relays, NIP-05, Lightning address, wallet status. Follow-list recovery. If another app wipes or shrinks your follows, scan your relays and restore a healthy earlier version. Check your relays: each one carries its own icon, and you can ask whether it is answering, gated behind payment or login, or holding none of your notes, which is the thing worth knowing before you drop it. Your npub as a QR code, with your profile picture in the middle, so handing someone your key does not mean reading out sixty-three characters. ✍️ Post without leaving the page A composer for notes with @mention autocomplete across your follows and all of Nostr, embedded note previews, link cards, and image/video upload to your own Blossom servers. Drafts autosave per account and are encrypted at rest. A short review countdown lets you read the note exactly as it will publish. Comment on any web page (NIP-22), and keep the bookmark lists your other clients write (NIP-51). 🔔 Notifications at a glance A bell shows replies, mentions, reposts, reactions, and zaps for your active account, each opening in your preferred web client. Reply to a note or a comment without leaving Sidecar. What you are answering stays on screen while you write, through the preview and the review countdown both. Your circle comes first: replies from outside your follows, and their follows, are gathered into a counted group at the bottom rather than mixed in. Nothing is hidden and nothing is deleted. Mute lists written by any client are respected, including muted words, hashtags, threads, and senders. ⚡ Lightning wallet (Nostr Wallet Connect) Connect your own self-custody Lightning wallet over Nostr Wallet Connect. If you don't have one yet, built-in suggestions help you pick. Send (BOLT11 or Lightning address, resolved up front so you see the real recipient), receive with a QR, view history, and back up or export your connection. Pay a Lightning invoice from any page, including one the site copies to the clipboard, plus a WebLN provider with per-site spending budgets you can edit or revoke at any time. Automatic zaps, capped and only on sites you've actually signed into. Balance in sats, BTC, or fiat, with a 24-hour price chart. Sidecar never holds your funds. You stay in control of your own wallet. 🎭 Twelve themes A gallery you can filter by dark or light, showing a live preview of each one before you choose it. Six are drawn for low light and six for daylight, each with its own display typeface, textures, and balance animation. A single switch turns the animations off. 🛡️ Private by design Open source. No analytics, no tracking, no remote code. Everything runs locally in your browser, and link previews are fetched with a guard against private-network requests. Works in Chrome, Brave, Edge, and other Chromium browsers. Pin Sidecar, open the side panel, and you're ready. 🍸 🗞️ What's new 1.12.0 • Reply to a note or a comment straight from the bell, with what you are answering held on screen while you write it, through the preview and the countdown both. • Your circle first: replies from people outside your follows, and their follows, are gathered into a counted group at the bottom instead of mixed in. Nothing is hidden, because a filter that hides is a filter that eventually eats the reply that mattered. • Relay sign-in (NIP-42) now covers reading, not just posting. Relays that gate reads were quietly serving the panel nothing at all. • Every relay in your list carries its own icon, read from the relay itself. • Recent activity can be checked rather than believed: each signature records what it signed, and the row opens that event in your client. • Zap notifications say how much far more often, reading the amount from the invoice when the sending app leaves it out. On one real inbox that went from 93 of 150 to all 150. • Repost and reply marks are drawn now instead of emoji, so they take your theme's color rather than your operating system's. A reaction still shows the sender's own emoji, because that is content and not decoration. • Relay connections leaked until the browser ran out of them, and then nothing could connect: every relay reported a timeout while those same relays answered fine outside the browser, and only a restart helped. Fixed, with a button to rebuild connections if you ever get there again. • A signing request could hang with nothing on screen, blocking every request queued behind it. Reactions and reposts appeared to do nothing at all. • Your relay list could be quietly replaced with Sidecar's defaults when a lookup timed out. The two are told apart now, and publishing is blocked until a lookup actually succeeds. • Names in notifications no longer come back as npubs after one bad moment on the relays. 1.11.0 • The theme picker is a gallery: filter dark or light and see each theme live, in its own colors and type, before you pick it. Three new ones bring the set to twelve. • Relay health: ask your relays, one by one, whether they are answering, gated, silent, or simply not holding any of your notes. • Zaps you send now read as zaps, with the name and picture of whoever you paid. • Your npub as a QR code, with your profile picture in the middle of it. • The Wallet tab could go blank and stay blank until you switched accounts. Fixed, and it now says what went wrong and offers to try again. • NIP-05 no longer gives the same mild warning whether you are offline or your address points at someone else's key. • Bookmarks are sorted newest first, matching what every other client shows, and an empty list carries a line from an early twentieth century writer instead of nothing at all. • The version number sits at the foot of the lock screen and copies with a tap, for the moment you need to say which build you are on.