Pubky SDK

Ergonomic building blocks for Pubky apps: one facade (Pubky) plus focused actors for sessions, storage API, signer helpers, and QR auth flow for keyless apps.

Rust implementation of Pubky SDK.

Install

# Cargo.toml
[dependencies]
pubky = "0.x"            # this crate
# Optional helpers used in examples:
# pubky-testnet = "0.x"

Quick start

use pubky::prelude::*;
use pubky::ClientId;

# async fn run() -> pubky::Result<()> {

let pubky = Pubky::new()?; // or Pubky::testnet() for local testnet.

// 1) Create a new random key user and bound to a Signer
let keypair = Keypair::random();
let signer = pubky.signer(keypair);

// 2) Sign up on a homeserver (identified by its public key)
let homeserver = PublicKey::try_from("o4dksf...uyy").unwrap();
signer.signup(&homeserver, None).await?;
let session = signer.signin(ClientId::new("my-cool-app").unwrap()).await?;

// 3) Read/Write as the signed-in user
session.storage().put("/pub/my-cool-app/hello.txt", "hello").await?;
let body = session.storage().get("/pub/my-cool-app/hello.txt").await?.text().await?;
assert_eq!(&body, "hello");

// 4) Public read of another user’s file
let txt = pubky
    .public_storage()
    .get(format!(
        "{}/pub/my-cool-app/hello.txt",
        session.info().public_key()
    ))
    .await?
    .text().await?;
assert_eq!(txt, "hello");

// 5) Keyless app flow (QR/deeplink)
let caps = Capabilities::builder().write("/pub/example.com/").finish();
let flow = pubky.start_cookie_auth_flow(&caps, AuthFlowKind::signin())?;
println!("Scan to sign in: {}", flow.authorization_url());
let app_session = flow.await_approval().await?;

// 6) Optional (advanced): publish or resolve PKDNS (_pubky) records
signer.pkdns().publish_homeserver_if_stale(None).await?;
let resolved = signer.pkdns().get_homeserver().await;
println!("Your current homeserver: {:?}", resolved);

# Ok(()) }

Key formats (display vs transport)

PublicKey has two string representations:

• Display format: pubky<z32> (used for logs/UI and human-facing identifiers).
• Transport/storage format: raw z32 (used for hostnames, headers, query params, serde/JSON, and database storage).

Use .z32() whenever you are building hostnames or transport values (for example _pubky.<z32> or the pubky-host header). Use Display/.to_string() when you want the prefixed identifier for people.

Reuse a single facade across your app

Use a shared Pubky (via cloning it, passing down as argument or behind OnceCell) instead of constructing one per request. This avoids reinitializing transports and keeps the same client available for repeated usage.

Mental model

• Pubky - facade, always start here! Owns the transport and constructs actors.
• PubkySigner - local key holder. Can signup, signin, approve QR auth, publish PKDNS.
• PubkySession - authenticated “as me” handle. Exposes session-scoped storage.
• GrantManager - account-level grant listing and revocation using an authenticated root session.
• PublicStorage - unauthenticated reads of others’ public data.
• Pkdns - resolve/publish _pubky records.

Transport:

• PubkyHttpClient : handles requests to pubky public-key hosts.

Examples

Storage API (session & public)

Session (authenticated):

use pubky::{ClientId, Keypair, Pubky};

# async fn run(keypair: Keypair) -> pubky::Result<()> {

let pubky = Pubky::new()?;
let session = pubky
    .signer(keypair)
    .signin(ClientId::new("my-cool-app").unwrap())
    .await?;

let storage = session.storage();
storage.put("/pub/my-cool-app/data.txt", "hi").await?;
let text = storage.get("/pub/my-cool-app/data.txt").await?.text().await?;

# Ok(()) }

Public (read-only):

use pubky::{Pubky, PublicKey};

# async fn run(user_id: PublicKey) -> pubky::Result<()> {

let pubky = Pubky::new()?;
let public = pubky.public_storage();

let file = public
    .get(format!("{user_id}/pub/example.com/file.bin"))
    .await?
    .bytes()
    .await?;

let entries = public
    .list(format!("{user_id}/pub/example.com/"))?
    .limit(10)
    .send()
    .await?;
for entry in entries {
    println!("{}", entry.to_pubky_url());
}

# Ok(()) }

See the Public Storage example.

Path rules:

• Session storage uses absolute paths like "/pub/app/file.txt".
• Public storage uses addressed form pubky<user>/pub/app/file.txt (preferred) or pubky://<user>/....
• A storage path cannot be both an exact file and an implicit folder prefix. For example:
  • if /pub/app/foo exists, writing /pub/app/foo/bar.json returns 409 Conflict.
  • if descendants under /pub/app/foo/ exist, writing /pub/app/foo returns 409 Conflict.

Convention: put your app’s public data under a domain-like folder in /pub, e.g. /pub/my-new-app/.

Resolve identifiers into transport URLs

Need to feed a public resource into a raw HTTP client? Use [resolve_pubky] to transform the human-facing identifier into the HTTPS homeserver URL:

# use pubky::resolve_pubky;
# fn main() -> pubky::Result<()> {
let url = resolve_pubky("pubkyoperrr8wsbpr3ue9d4qj41ge1kcc6r7fdiy6o3ugjrrhi4y77rdo/pub/pubky.app/posts/0033X02JAN0SG")?;
assert_eq!(
    url.as_str(),
    "https://_pubky.operrr8wsbpr3ue9d4qj41ge1kcc6r7fdiy6o3ugjrrhi4y77rdo/pub/pubky.app/posts/0033X02JAN0SG"
);
# Ok(())
# }

PKDNS (Pkarr)

Resolve another user’s homeserver (_pubky record), or publish your own via the signer.

use pubky::{Pubky, PublicKey, Keypair};
# async fn run(other: PublicKey, new_homeserver_id: PublicKey) -> pubky::Result<()> {
let pubky = Pubky::new()?;

// read-only homeserver resolver
let host = pubky.get_homeserver_of(&other).await;

// publish with your key
let signer = pubky.signer(Keypair::random());
signer.pkdns().publish_homeserver_if_stale(None).await?;
// or force republish (e.g. homeserver migration)
signer.pkdns().publish_homeserver_force(Some(&new_homeserver_id)).await?;
// resolve your own homeserver
signer.pkdns().get_homeserver().await?;

# Ok(()) }

Pubky QR auth for third-party and keyless apps

Request an authorization URL and await approval.

Typical usage:

1. Start an auth flow with pubky.start_grant_auth_flow(&caps, ..) (or pubky.start_cookie_auth_flow(&caps, ..) for the cookie variant). You can also use PubkyGrantAuthFlow::builder() / PubkyCookieAuthFlow::builder() to set a custom relay.
2. Show authorization_url() (QR/deeplink) to the signing device (e.g., Pubky Ring — iOS / Android).
3. Await await_approval() to obtain a session-bound PubkySession, or await_credential() for a raw GrantCredential/CookieCredential that you can persist, inspect, or lift into a session later via PubkySession::from_{grant,cookie}_credential.

# use pubky::{Pubky, Capabilities, Keypair, AuthFlowKind};
# async fn auth() -> pubky::Result<()> {

let pubky = Pubky::new()?;
// Read/Write capabilities for acme.app route
let caps = Capabilities::builder().read_write("pub/example.com/").finish();

// Start the flow using the default relay (see “Relay & reliability” below)
let flow = pubky.start_cookie_auth_flow(&caps, AuthFlowKind::signin())?;
println!("Scan to sign in: {}", flow.authorization_url());

// On the signing device, approve with: signer.approve_auth(flow.authorization_url()).await?;
# pubky.signer(Keypair::random()).approve_auth(flow.authorization_url()).await?;

let session = flow.await_approval().await?;

# Ok(()) }

Approve an auth request

signer.approve_auth(authorization_url).await?;

See the fully functional Auth Flow Example.

Relay & reliability

• If you don’t specify a relay, the auth flow defaults to a Synonym-hosted relay. If that relay is down, logins won’t complete.
• For production and larger apps, run your own relay (MIT, Docker): https://httprelay.io. The channel is derived as base64url(hash(secret)); the token is end-to-end encrypted with the secret and cannot be decrypted by the relay.

Custom relay example

# use pubky::{Pubky, PubkyGrantAuthFlow, Capabilities, AuthFlowKind, ClientId};
# async fn custom_relay() -> pubky::Result<()> {
let pubky = Pubky::new()?;
let caps = Capabilities::builder().read("pub/example.com/").finish();
let client_id = ClientId::new("my.app").unwrap();
let auth_flow = PubkyGrantAuthFlow::builder(&caps, AuthFlowKind::signin(), client_id)
    .client(pubky.client().clone())
    .relay(url::Url::parse("http://localhost:8080/inbox/")?) // your relay
    .start()?;
# Ok(()) }

Tip: reuse pubky.client() when customising the relay so the flow shares TLS and pkarr configuration with the rest of your application.

Features

• json: enable Storage helpers (.get_json() / .put_json()) and serde on certain types.

# Cargo.toml
[dependencies]
pubky = { version = "x.y.z", features = ["json"] }

Testing locally

Spin up an ephemeral testnet (DHT + homeserver + relay) and run your tests fully offline:

# use pubky_testnet::{EphemeralTestnet, pubky::{ClientId, Keypair}};
# async fn test() -> pubky_testnet::pubky::Result<()> {

let testnet = EphemeralTestnet::builder().build().await.unwrap();
let homeserver  = testnet.homeserver_app();
let pubky = testnet.sdk()?;

let signer = pubky.signer(Keypair::random());
signer.signup(&homeserver.public_key().into(), None).await?;
let session = signer
    .signin(ClientId::new("my-cool-app").unwrap())
    .await?;

session.storage().put("/pub/my-cool-app/hello.txt", "hi").await?;
let s = session.storage().get("/pub/my-cool-app/hello.txt").await?.text().await?;
assert_eq!(s, "hi");

# Ok(()) }

Keypair and Session persistence

Encrypted Keypair secrets (.pkarr):

use pubky::Pubky;
# fn run() -> pubky::Result<()> {
let pubky = Pubky::new()?;
let signer = pubky.signer_from_recovery_file("/path/to/alice.pkarr", "passphrase")?;
# Ok(()) }

Session secrets (.sess):

use pubky::{ClientId, Keypair, Pubky};
# async fn run() -> pubky::Result<()> {
let pubky = Pubky::new()?;
let keypair = Keypair::random();
let session = pubky
    .signer(keypair)
    .signin(ClientId::new("my-cool-app").unwrap())
    .await?;
session.write_secret_file("alice.sess").unwrap();
let restored = pubky.session_from_file("alice.sess").await?;

# let _ = std::fs::remove_file("alice.sess");
# Ok(()) }

Security: the .sess secret is a bearer token. Anyone holding it can act as the user within the granted capabilities. Treat it like a password.

Example code

Check more examples using the Pubky SDK.

JS bindings

Find a wrapper of this crate using wasm_bindgen in npmjs.com. Or build on pubky-sdk codebase under pubky-sdk/bindings/js.

License: MIT Relay: https://httprelay.io (open source; run your own for production)