A portable DNS resolver in a single binary. Block ads on any network, name your local services (`frontend.numa`), and override any hostname with auto-revert — all from your laptop, no cloud account or Raspberry Pi required.
Built from scratch in Rust. Zero DNS libraries. RFC 1035 wire protocol parsed by hand. Recursive resolution from root nameservers with full DNSSEC chain-of-trust validation. One ~8MB binary, everything embedded.
Built from scratch in Rust. Zero DNS libraries. RFC 1035 wire protocol parsed by hand. Caching, ad blocking, and local service domains out of the box. Optional recursive resolution from root nameservers with full DNSSEC chain-of-trust validation. One ~8MB binary, everything embedded.
385K+ domains blocked via [Hagezi Pro](https://github.com/hagezi/dns-blocklists). Works on any network — coffee shops, hotels, airports. Travels with your laptop.
Two resolution modes: **forward** (relay to Quad9/Cloudflare via encrypted DoH) or **recursive** (resolve from root nameservers — no upstream dependency, no single entity sees your full query pattern). DNSSEC validates the full chain of trust: RRSIG signatures, DNSKEY verification, DS delegation, NSEC/NSEC3 denial proofs. [Read how it works →](https://numa.rs/blog/posts/dnssec-from-scratch.html)
By default, Numa forwards to your existing system DNS — everything works as before, just with caching and ad blocking on top. For full privacy, set `mode = "recursive"` — Numa resolves directly from root nameservers. No upstream dependency, no single entity sees your full query pattern. DNSSEC validates the full chain of trust: RRSIG signatures, DNSKEY verification, DS delegation, NSEC/NSEC3 denial proofs. [Read how it works →](https://numa.rs/blog/posts/dnssec-from-scratch.html)
- Local zones, ephemeral overrides with auto-revert via REST API
DNSSEC implementation: DNSKEY/DS/RRSIG record parsing, canonical wire format
for signed data, key tag computation (RFC 4034), DS digest verification.
Chain walks from zone → TLD → root trust anchor. ECDSA P-256 signature
verification in 174ns. TLD chain pre-warmed on startup. Referral DS records
piggybacked from authority sections during resolution.
NSEC/NSEC3 authenticated denial of existence: NXDOMAIN gap proofs, NSEC3
closest encloser proofs (3-part per RFC 5155), NODATA type absence proofs,
authority-section RRSIG verification. Iteration cap at 500 for NSEC3 DoS
prevention.
What it doesn't do (yet): no authoritative zone serving (AXFR/NOTIFY).
Single binary, macOS + Linux. MIT license.
https://github.com/razvandimescu/numa
---
### Lobsters (invite-only)
**Title:** Numa — DNS resolver from scratch in Rust, no DNS libraries
**Body:**
I built a DNS resolver in Rust — RFC 1035 wire protocol parsed by hand,
no `trust-dns` or `hickory-dns`. Started as a learning project, became
my daily system DNS.
Beyond resolving, it does local `.numa` domains with auto HTTPS reverse
proxy (register `frontend.numa → localhost:5173`, get a green lock and
WebSocket passthrough), and LAN service discovery via UDP multicast —
two machines running Numa find each other's services automatically.
Implementation bits I found interesting: DNS label compression (chained
2-byte pointers back into the packet), browsers rejecting wildcard certs
under single-label TLDs (`*.numa` fails — need per-service SANs), and
`SO_REUSEPORT` on macOS for multiple processes binding the same multicast
port.
Set `mode = "recursive"` for DNSSEC-validated resolution from root
nameservers — no upstream, no middleman.
Single binary, macOS + Linux.
https://github.com/razvandimescu/numa
---
### r/coolgithubprojects
**Post type:** Image post with `hero-demo.gif`, GitHub link in first comment.
**Title:** Numa — portable DNS resolver built from scratch in Rust. Ad blocking, local HTTPS domains, LAN discovery, recursive resolution with DNSSEC. Single binary.
**First comment (post immediately):**
https://github.com/razvandimescu/numa
```
brew install razvandimescu/tap/numa && sudo numa
```
No DNS libraries — RFC 1035 wire protocol parsed by hand.
Recursive resolution from root nameservers with full DNSSEC
chain-of-trust validation. 385K+ blocked ad domains.
.numa local domains with auto TLS and WebSocket proxy.
---
### r/sideproject
**Title:** I built a DNS resolver from scratch in Rust — it's now my daily system DNS
**Body:**
Last year I wanted to understand how DNS actually works at the wire
level, so I started parsing RFC 1035 packets by hand. No DNS libraries,
no trust-dns, no hickory-dns — just bytes and the spec.
It turned into something I use every day. What it does now:
- **Ad blocking** on any network (coffee shops, airports) — 385K+
domains blocked, travels with my laptop
- **Local service naming** — `https://frontend.numa` instead of
`localhost:5173`, with auto-generated TLS certs and WebSocket
passthrough for HMR
- **Recursive resolution** from root nameservers with DNSSEC
chain-of-trust validation — set `mode = "recursive"` for full
privacy, no upstream dependency, no single entity sees my query
pattern
- **LAN discovery** — two machines running Numa find each other's
services automatically via mDNS
Single Rust binary, ~8MB, MIT license. `sudo numa install` and it's your
system DNS — caching, ad blocking, .numa domains, zero config changes.
I wrote about the technical journey here:
- [I Built a DNS Resolver from Scratch](https://numa.rs/blog/posts/dns-from-scratch.html)
- [Implementing DNSSEC from Scratch](https://numa.rs/blog/posts/dnssec-from-scratch.html)
<title>Numa — DNS you own. Everywhere you go.</title>
<metaname="description"content="DNS you own. Recursive resolver with full DNSSEC validation, ad blocking, .numa local domains, developer overrides. A single portable binary built from scratch in Rust.">
<metaname="description"content="DNS you own. Portable DNS resolver with caching, ad blocking, .numa local domains, developer overrides. Optional recursive resolution with full DNSSEC validation. Built from scratch in Rust.">
<linkrel="canonical"href="https://numa.rs">
<metaproperty="og:title"content="Numa — DNS you own. Everywhere you go.">
<metaproperty="og:description"content="Recursive DNS resolver with full DNSSEC validation, ad blocking, .numa local domains, and developer overrides. Built from scratch in Rust.">
<metaproperty="og:description"content="Portable DNS resolver with caching, ad blocking, .numa local domains, and developer overrides. Optional recursive resolution with full DNSSEC validation. Built from scratch in Rust.">
<metaproperty="og:type"content="website">
<metaproperty="og:url"content="https://numa.rs">
<linkrel="stylesheet"href="/fonts/fonts.css">
@@ -1232,17 +1232,17 @@ footer .closing {
<divclass="reveal">
<divclass="section-label">How It Works</div>
<h2>What it does today</h2>
<pclass="lead">A recursive DNS resolver with DNSSEC validation, ad blocking, local service domains, and a REST API. Everything runs in a single binary.</p>
<pclass="lead">A DNS resolver with caching, ad blocking, local service domains, and a REST API. Optional recursive resolution with DNSSEC. Everything runs in a single binary.</p>
</div>
<divclass="layers-grid">
<divclass="layer-card reveal reveal-delay-1">
<divclass="layer-badge">Layer 1</div>
<h3>Resolve & Protect</h3>
<ul>
<li>Recursive resolution — resolve from root nameservers, no upstream needed</li>
eprintln!(" Numa will auto-start on boot and restart if killed.");
eprintln!(" Logs: journalctl -u numa -f");
eprintln!(" Run 'sudo numa service stop' to fully uninstall.\n");
eprintln!(" Run 'sudo numa uninstall' to restore original DNS.\n");
eprintln!(" Want full DNS sovereignty? Add to numa.toml:");
eprintln!(" [upstream]");
eprintln!(" mode = \"recursive\"\n");
Ok(())
}
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