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 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, 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 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. 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. 🎭 Sixteen themes A gallery you can filter by dark or light, showing a live preview of each one before you choose it. Eight are drawn for low light and eight 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 1.15.9 • Uploads find your own Blossom servers in both composers, and retry discovery after a missed lookup. • The full-size composer’s toolbar stays steady during uploads and PoW changes. Close moves to the top bar, and saved drafts take the card’s corner. 1.15.8 • Mentions and quotes written in the full-size composer now notify the people in them, and a pasted npub or nevent counts as a mention or a quote. • The full-size composer’s preview shows names, and a post can no longer get stuck on a relay that doesn’t answer. 1.15.7 • The seasonal theme’s card now appears right after an update, beside the update notice. • On its lock screen, the great tree stands in front of the drifting clouds again. 1.15.6 • Special editions: a seasonal theme, here for a few weeks of the year. The first is for Halloween, and it goes on over your own theme. • GIFs in both composers, and highlights: select text on any page, right-click, and share the passage to Nostr. • Notifications stay current and show names, and a profile opened from search shows the person on the first try. • Sidecar asks before posting the same note twice, and the download is smaller. 1.15.5 • Replies and polls open in the full-size composer, and a new switch makes it your default. • Saved drafts: a folder in both composers lists your other drafts, to switch between a note and your replies, or delete one. • Code in a note reads as code, with a copy button on each block, and the note you’re answering can be read in full. • A pasted image uploads in the full-size composer, and Auto Zaps start at 100 sats a zap. 1.15.4 • The reaction picker learns your favorites: its quick row becomes the eight reactions you use most, counted on this device only. • Notifications arrive with bootstrap relays off. A new switch, on by default, keeps reading them for replies and reactions. 1.15.3 • Bitcoin only: one switch takes local currency out of Sidecar. Your balance shows in sats or BTC, and no exchange rate is fetched. • Pay a Lightning link on sites you aren’t signed in to with Sidecar. Tapping one offers to pay it, and every payment still waits for your approval. • A ⋮ menu on every notification copies its event ID, the sender’s npub, the note it points to, or its signed JSON. • Replies sent to your inbox relays now show up in Notifications, and a wallet backup you just saved reads as saved. • Easier to see on the light themes: the zap bolt is lemon yellow everywhere, spinners visibly turn, and an upload stripes the whole Media button. 1.15.2 • Open tabs stay connected when Sidecar updates or restarts. A client you keep open no longer fails with “Sidecar was updated” until you reload it. • A warning before signing a follow list that suddenly grows by hundreds, which is how another account’s list looks. With more than one account, it names the account. 1.15.1 • The expanded composer’s text field is readable in every light theme, and its backgrounds are drawn at the panel’s scale instead of four times as large. Some themes received minor style refreshes. • Refreshing the wallet no longer empties the history and redraws it. 1.15.0 • Four new themes, two for dark mode and two for light, and one of the originals recut in black and white. • On this day: a line of history for today’s date at the foot of the Accounts tab, ready to share. It and the literary quotes can each be turned off. • Send shows a pasted invoice’s amount, description and expiry before you pay. A payment of 10,000 sats or more takes a second press, including one a site asks for. • Your relay setting reaches the clients you use: they are told your own relays, plus Sidecar’s defaults only while you use them. • The account overview shows a NIP-05 and Lightning address set in another client, and says “Couldn’t load” rather than “Not set” when your relays don’t answer.