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 (from 5 minutes to 24 hours, or when the browser closes), 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, and a tick on it to always allow that event type for that site. 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 lists what each site signs without asking, with a ✕ to revoke, 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 every account and its wallet connection, and restoring it never touches accounts already on the device. 👤 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. Data recovery. If another app wipes or shrinks your follows, mutes, bookmarks, profile, or relay lists, scan your relays for earlier versions and restore the one you pick. 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, and a folder lets you switch between your note and your replies. A short review countdown lets you read the note exactly as it will publish. Post a poll instead of a note, and read the full tally in the panel when the votes come in. 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, under a Replying to label, 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. Mute a person, a note or a thread yourself from the ⋮ menu, and follow, unfollow or mute from search results. 📺 Live video Watch livestreams and replays in a player above the panel: browse what is live, upcoming and past, save streams, chat with the host, and zap the stream or a comment from your own wallet. Open a stream from its address, and copy any stream's address to send it on. Playback keeps going while you move around Sidecar, lock it, or approve a signature, and a switch in Settings turns it all off. ⚡ 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 to an invoice or a Lightning address: a pasted invoice shows its amount, description and expiry before you pay, and an address resolves to 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. A payment of 10,000 sats or more always asks twice. A payment card can pay from another of your accounts and keep the site on it, every payment shows its progress in one bar at the foot of the panel, and a refused payment says why. If another wallet extension answers a page first, a switch lets Sidecar answer instead. Automatic zaps, capped and only on sites you've actually signed into. Podcasting 2.0 boosts, paid from your own wallet, with the show and the message named on the approval. 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. 🎭 Twenty themes A gallery you can filter by dark or light, showing a live preview of each one before you choose it. Ten are drawn for low light and ten 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 1.16.3 • Notes and replies from the full-size composer reach all of your relays, and the receipt shows which relays accepted each one. • Poll results find more votes, and a menu copies a poll’s ID, link or JSON. • Nostr Vault joins the app directory, and more Lightning wallets can connect. 1.16.2 • A Blitz wallet no longer fills your lock screen with alerts: Sidecar stops polling it, and reads its balance when you open the panel or tap refresh. • The panel opens lighter, and the account Overview folds while a video plays. • Blitz and LNbits join the wallet directory. 1.16.1 • Always allow an event type for a site: one tick on the approval card, and that kind signs without asking. Activity lists every standing grant with a ✕ to revoke. • A payment card can pay from another of your accounts, every payment shows its progress in one bar at the foot of the panel, and a refused payment says why. • Open a stream from its address, and copy any stream’s address. Stream hosts show their own names and pictures, and a stream with a broken image gets a thumbnail. • Use Sidecar for Lightning on pages another wallet claimed, by a switch in Settings or an offer in the panel. • The composer says Replying to, with a Reply button. Eight new apps and a search box on the Welcome page. • Fixes: Allow all leaves lists, profiles and zap requests to their own cards, the mention popup opens only at the start of a word, the post receipt no longer blocks a new note, the approval card scrolls on its own, and forgetting a site ends its standing approvals. 1.16.0 • Live video: watch livestreams and replays above the panel, chat with the host, zap the stream, and save streams. A switch in Settings turns it off. • Mute a person, a note or a thread from the notifications menu, and follow, unfollow or mute from search. The profile card is one row of icons. • Auto-lock can wait 30 minutes, 8 or 24 hours, and “Never” now reads “When browser closes.” • Four new themes, for twenty in all. 1.15.x (1.15.0 to 1.15.9) • Seasonal themes: a special edition for a few weeks of the year, worn over your own theme, plus four more themes and a card with a line of history for today’s date. • GIFs in both composers, and highlights: select text on any page and share the passage to Nostr. • The full-size composer grew up: replies and polls open in the tab, saved drafts switch between a note and your replies, mentions and quotes notify the people in them, uploads find your own Blossom servers, and its toolbar stays steady. • Notifications stay current and show names, each one has a ⋮ menu, and a profile opened from search shows the person on the first try. • Wallet: Send shows an invoice’s amount, description and expiry before you pay, a payment of 10,000 sats or more takes a second press, Lightning links work on sites you aren’t signed in to, and a switch makes Sidecar Bitcoin only. • Open tabs stay connected when Sidecar updates, and a warning comes before signing a follow list that suddenly grows by hundreds.