Building on Nostr: Developer Tools and First Steps

Welcome back to our 10-part series on Nostr! We've covered the essentials so far: The intro in Post 1, history in Post 2, technical primer in Post 3, comparison to centralized media in Post 4, and beginner guide in Post 5. Links: 1, 2, 3, 4, 5. Now, we shift gears for developers. If you're a coder looking to build apps, bots, or integrations on Nostr, this post is your launchpad. We'll explore the protocol's dev-friendly design, key tools and SDKs (focusing on JavaScript and Rust as of 2026), and walk through first steps with code snippets. Nostr's simplicity means you can prototype quickly—no blockchain expertise required. Let's build something!

Why Build on Nostr? The Developer Appeal

Nostr's protocol is dev heaven: Lightweight JSON over WebSockets, extensible via NIPs, and fully open-source. No API keys, rate limits, or vendor lock-in like Big Tech. Build clients, relays, bots, or niche tools (e.g., a zap-enabled newsletter). Key perks:

• Interoperability: Any client supporting the same NIPs works across relays.
• Extensibility: Add features via new NIPs—community-voted.
• Crypto Integration: Built-in Lightning for payments, secp256k1 keys align with Bitcoin/Ethereum tools.

Challenges? Handling async comms and key management, but SDKs abstract that.

Essential Developer Resources

Start here:

• Nostr GitHub: github.com/nostr-protocol/nostr – Core spec.
• NIPs Repo: github.com/nostr-protocol/nips – Over 100 proposals; must-read: NIP-01 (events), NIP-05 (identities), NIP-57 (zaps).
• Rust-Nostr Book: rust-nostr.org – Guides for Rust devs.
• Community: Join #nostr-dev on relays or Discord/Slack groups.

For up-to-date tools (as of Jan 2026), use web searches or GitHub topics like "nostr-sdk".

Recommended SDKs and Libraries

Focus on popular, maintained ones:

• JavaScript/TypeScript:

  • nostr-tools: Lightweight, browser/node-friendly. Great for quick prototypes. Install: npm i nostr-tools.
  • nostr-sdk-js (from rust-nostr): High-level bindings, works in web, Node, React Native. Handles pools, signers. Install: npm i @rust-nostr/nostr-sdk.

• Rust:

  • nostr-sdk: High-level client from rust-nostr. Async, feature-rich for bots/clients. Install: cargo add nostr-sdk (latest v0.XX as of Nov 2025).
  • Core nostr crate: For low-level protocol impl.

Other languages: nostr-sdk for Python, Go-nostr, etc.

First Steps: Setting Up Your Dev Environment

1. Generate Keys: Use SDK methods or tools like nostr-tools/generatePrivateKey().
2. Choose Relays: Test with public ones like wss://relay.damus.io.
3. Handle Events: Sign, publish, subscribe.

We'll use code examples. Note: These are simplified; error handling omitted for brevity. Test in your IDE.

Code Example: Basic Client in JavaScript (Using nostr-tools)

This connects to a relay, publishes a note, and subscribes to events.

// Install: npm i nostr-tools
import { relayInit, generatePrivateKey, getPublicKey, finalizeEvent, verifyEvent } from 'nostr-tools';

async function nostrDemo() {
  const privateKey = generatePrivateKey(); // Or use existing
  const publicKey = getPublicKey(privateKey);

  const relay = relayInit('wss://relay.damus.io');
  await relay.connect();

  relay.on('connect', () => console.log('Connected!'));
  relay.on('error', () => console.log('Error!'));

  // Publish a note (kind 1)
  const event = finalizeEvent({
    kind: 1,
    created_at: Math.floor(Date.now() / 1000),
    tags: [],
    content: 'Hello from JS on Nostr!',
  }, privateKey);

  if (verifyEvent(event)) {
    await relay.publish(event);
    console.log('Published:', event);
  }

  // Subscribe to events
  const sub = relay.sub([{ kinds: [1], authors: [publicKey], limit: 5 }]);
  sub.on('event', event => console.log('Received:', event));
  sub.on('eose', () => sub.unsub()); // End of stored events
}

nostrDemo();

Run in Node or browser. This uses NIP-01 basics.

Code Example: Basic Client in Rust (Using nostr-sdk)

Rust's async nature shines for performant apps.

// Cargo.toml: [dependencies] nostr-sdk = "0.26" (check latest)
use nostr_sdk::{prelude::*, Client, Options, RelayPoolNotification};

#[tokio::main]
async fn main() -> Result<()> {
    let keys = Keys::generate(); // Or from secret
    let opts = Options::new().wait_for_send(true);
    let client = Client::with_opts(&keys, opts);

    client.add_relay("wss://relay.damus.io").await?;

    client.connect().await;
    println!("Connected!");

    // Publish a note
    let event = EventBuilder::new_text_note("Hello from Rust on Nostr!", []).to_event(&keys)?;
    client.send_event(event).await?;
    println!("Published!");

    // Subscribe
    let filter = Filter::new().kind(Kind::TextNote).author(keys.public_key());
    let sub_id = client.subscribe(vec![filter], None).await?;

    // Handle notifications
    client.handle_notifications(|notification| async {
        if let RelayPoolNotification::Event { event, .. } = notification {
            println!("Received: {:?}", event);
        }
        Ok(false) // Continue
    }).await?;

    Ok(())
}

This uses high-level Client; compile with cargo run.

Next-Level Tips

• NIPs for Features: Implement NIP-04 for DMs, NIP-23 for long-form.
• Testing: Use local relays like strfry for dev.
• Security: Secure keys; use signers for delegation (NIP-46).
• Scaling: For bots, use relay pools.

In Copenhagen? Check local Bitcoin/Nostr meetups for collab.

Wrapping Up

With these tools, you're set to build. Fork a repo, submit a NIP, or create a bot. Nostr's dev community is welcoming—start small!

Next: "Top Nostr Clients and Apps: Reviews and Recommendations."

Hack away! Share your builds below or zap on Nostr.

What will you build first? Tell us!