Spike native shells and define local-first integrations

.gitignore

@@ -1,4 +1,6 @@
 /target/
+/spikes/target/
+/spikes/*/target/
 /.idea/
 /.zed/
 /.vscode/
@@ -11,4 +13,3 @@
 # Upstream research checkouts live beside this repository, never inside it.
 /Research/
 /research-checkouts/
-

Cargo.toml

@@ -1,11 +1,17 @@
 [workspace]
-members = ["apps/lumbridge", "crates/lumbridge-core"]
+members = [
+    "apps/lumbridge",
+    "crates/lumbridge-buzz",
+    "crates/lumbridge-core",
+    "crates/lumbridge-storage",
+]
+exclude = ["spikes"]
 resolver = "2"
 
 [workspace.package]
 version = "0.0.1"
 edition = "2024"
-rust-version = "1.85"
+rust-version = "1.94"
 license = "Apache-2.0"
 repository = "https://git.karti.ai/lumbridge-public/lumbridge-code"
 
@@ -15,4 +21,3 @@ unsafe_code = "forbid"
 [workspace.lints.clippy]
 all = "warn"
 pedantic = "warn"
-

README.md

@@ -34,6 +34,8 @@ contracts before committing to a large implementation.
   profiles for OpenAI, Anthropic, Gemini, Groq, Cerebras, DeepSeek, and more.
 - Usage history, burn rate, reset windows, and forecasts with visible data
   provenance instead of invented precision.
+- Optional first-class Buzz channels, messages, agents, and confirmed redacted
+  pane sharing without making Buzz a requirement.
 
 Start with [the product spec](docs/PRODUCT_SPEC.md),
 [architecture](docs/ARCHITECTURE.md), [research map](docs/RESEARCH.md), and
@@ -51,3 +53,10 @@ cargo run -p lumbridge
 
 See [the testing strategy](docs/TESTING.md) for fake harnesses, ACP replay,
 terminal conformance, UI driving, recovery, performance, and packaging tests.
+
+The accepted local/remote boundary is recorded in
+[decision 0003](docs/decisions/0003-local-data-and-remote-sessions.md). The two
+native shell candidates live in [`spikes/`](spikes/), with results tracked in
+[the UI scorecard](docs/UI_SPIKE_SCORECARD.md).
+The signed-protocol and pane-sharing boundary is in
+[the Buzz integration design](docs/BUZZ_INTEGRATION.md).

crates/lumbridge-buzz/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "lumbridge-buzz"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+
+[dependencies]
+buzz-sdk = { git = "https://github.com/block/buzz.git", rev = "cb3144999bebc4939cb15b2200b373281d493b52" }
+nostr = "0.44"
+thiserror = "2"
+uuid = "1"
+
+[lints]
+workspace = true

crates/lumbridge-buzz/src/lib.rs

@@ -0,0 +1,209 @@
+//! Credential-free Buzz protocol preparation for Lumbridge.
+//!
+//! This crate validates the user's pane-sharing decision and delegates event
+//! construction to the upstream Buzz SDK. Signing, uploading, and publishing
+//! belong to platform adapters that can resolve an OS credential-store handle.
+
+use std::fmt;
+
+use nostr::EventBuilder;
+use uuid::Uuid;
+
+/// A locally configured Buzz identity without private key material.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct BuzzAccount {
+    /// Lumbridge-local stable identifier.
+    pub id: String,
+    /// Human-readable account label.
+    pub label: String,
+    /// Buzz relay/server URL.
+    pub relay_url: String,
+    /// Public Nostr identity in hexadecimal form.
+    pub public_key: String,
+    /// Opaque reference resolved by Keychain or Secret Service.
+    pub secret_store_handle: String,
+}
+
+/// Metadata produced after an approved screenshot has been uploaded.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct UploadedPaneImage {
+    /// Publicly retrievable attachment URL returned by Buzz storage.
+    pub url: String,
+    /// MIME type, normally `image/png` or `image/webp`.
+    pub media_type: String,
+    /// Lower-case SHA-256 digest of the uploaded bytes.
+    pub sha256: String,
+    /// Exact byte length of the upload.
+    pub size_bytes: u64,
+    /// Optional pixel dimensions.
+    pub dimensions: Option<(u32, u32)>,
+}
+
+impl UploadedPaneImage {
+    fn imeta(&self) -> Vec<String> {
+        let mut tag = vec![
+            "imeta".to_owned(),
+            format!("url {}", self.url),
+            format!("m {}", self.media_type),
+            format!("x {}", self.sha256),
+            format!("size {}", self.size_bytes),
+        ];
+        if let Some((width, height)) = self.dimensions {
+            tag.push(format!("dim {width}x{height}"));
+        }
+        tag
+    }
+}
+
+/// The explicit human approval associated with a pane share.
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct ShareApproval {
+    /// Destination selected in the preview UI.
+    pub channel_id: Uuid,
+    /// Final caption visible in the preview UI.
+    pub caption: String,
+    /// Whether redaction has run for this exact captured image.
+    pub redaction_reviewed: bool,
+    /// Whether the user confirmed the exact image, caption, and destination.
+    pub user_confirmed: bool,
+}
+
+/// Errors that prevent preparation of a pane share.
+#[derive(Debug)]
+pub enum ShareError {
+    /// Redaction review is mandatory before sharing a pane.
+    RedactionNotReviewed,
+    /// A user must confirm the final preview and destination.
+    NotConfirmed,
+    /// The uploaded attachment metadata is malformed.
+    InvalidAttachment(&'static str),
+    /// Buzz rejected the message fields.
+    Buzz(buzz_sdk::SdkError),
+}
+
+impl fmt::Display for ShareError {
+    fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> fmt::Result {
+        match self {
+            Self::RedactionNotReviewed => formatter.write_str("pane redaction was not reviewed"),
+            Self::NotConfirmed => formatter.write_str("pane share was not confirmed"),
+            Self::InvalidAttachment(reason) => {
+                write!(formatter, "invalid pane attachment: {reason}")
+            }
+            Self::Buzz(error) => write!(formatter, "Buzz rejected pane share: {error}"),
+        }
+    }
+}
+
+impl std::error::Error for ShareError {}
+
+impl From<buzz_sdk::SdkError> for ShareError {
+    fn from(error: buzz_sdk::SdkError) -> Self {
+        Self::Buzz(error)
+    }
+}
+
+/// Build an unsigned Buzz message only after the share safety gate passes.
+///
+/// The returned builder must be signed by an identity obtained from the OS
+/// credential store and then published by the Buzz transport adapter.
+///
+/// # Errors
+///
+/// Returns an error when review/confirmation is missing, attachment metadata is
+/// unsafe, or the Buzz SDK rejects the event.
+pub fn prepare_pane_share(
+    approval: &ShareApproval,
+    image: &UploadedPaneImage,
+) -> Result<EventBuilder, ShareError> {
+    if !approval.redaction_reviewed {
+        return Err(ShareError::RedactionNotReviewed);
+    }
+    if !approval.user_confirmed {
+        return Err(ShareError::NotConfirmed);
+    }
+    if !matches!(image.media_type.as_str(), "image/png" | "image/webp") {
+        return Err(ShareError::InvalidAttachment("unsupported image type"));
+    }
+    if image.sha256.len() != 64 || !image.sha256.bytes().all(|byte| byte.is_ascii_hexdigit()) {
+        return Err(ShareError::InvalidAttachment(
+            "SHA-256 must be 64 hexadecimal characters",
+        ));
+    }
+    if image.size_bytes == 0 {
+        return Err(ShareError::InvalidAttachment("image is empty"));
+    }
+
+    let content = if approval.caption.trim().is_empty() {
+        format!("![Lumbridge pane]({})", image.url)
+    } else {
+        format!(
+            "{}\n\n![Lumbridge pane]({})",
+            approval.caption.trim(),
+            image.url
+        )
+    };
+    buzz_sdk::build_message(
+        approval.channel_id,
+        &content,
+        None,
+        &[],
+        false,
+        &[image.imeta()],
+    )
+    .map_err(Into::into)
+}
+
+#[cfg(test)]
+mod tests {
+    use nostr::{Keys, Kind};
+
+    use super::{ShareApproval, ShareError, UploadedPaneImage, prepare_pane_share};
+
+    fn image() -> UploadedPaneImage {
+        UploadedPaneImage {
+            url: "https://buzz.example/upload/pane.png".into(),
+            media_type: "image/png".into(),
+            sha256: "a".repeat(64),
+            size_bytes: 42_000,
+            dimensions: Some((1_720, 1_400)),
+        }
+    }
+
+    fn approval() -> ShareApproval {
+        ShareApproval {
+            channel_id: uuid::uuid!("5088492f-f83b-41e1-b2cd-95cc741b4521"),
+            caption: "Lumbridge GPUI spike".into(),
+            redaction_reviewed: true,
+            user_confirmed: true,
+        }
+    }
+
+    #[test]
+    fn requires_review_and_confirmation() {
+        let mut decision = approval();
+        decision.redaction_reviewed = false;
+        assert!(matches!(
+            prepare_pane_share(&decision, &image()),
+            Err(ShareError::RedactionNotReviewed)
+        ));
+
+        decision.redaction_reviewed = true;
+        decision.user_confirmed = false;
+        assert!(matches!(
+            prepare_pane_share(&decision, &image()),
+            Err(ShareError::NotConfirmed)
+        ));
+    }
+
+    #[test]
+    fn builds_a_signable_buzz_stream_message() {
+        let event = prepare_pane_share(&approval(), &image())
+            .expect("approved share should build")
+            .sign_with_keys(&Keys::generate())
+            .expect("test identity should sign");
+
+        assert_eq!(event.kind, Kind::Custom(9));
+        assert!(event.content.contains("Lumbridge GPUI spike"));
+        assert!(event.content.contains("pane.png"));
+    }
+}

crates/lumbridge-core/src/lib.rs

@@ -2,6 +2,56 @@
 
 use std::fmt;
 
+/// The transport Lumbridge uses to reach a user-owned remote machine.
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum RemoteTransport {
+    /// The system OpenSSH client, including the user's SSH config, `ProxyJump`,
+    /// agent, and a Tailscale `MagicDNS` name or tailnet IP when supplied.
+    OpenSsh,
+    /// The Tailscale CLI's SSH proxy and host-key verification path.
+    TailscaleSsh,
+}
+
+impl RemoteTransport {
+    #[must_use]
+    pub const fn storage_name(self) -> &'static str {
+        match self {
+            Self::OpenSsh => "openssh",
+            Self::TailscaleSsh => "tailscale-ssh",
+        }
+    }
+
+    #[must_use]
+    pub fn from_storage_name(value: &str) -> Option<Self> {
+        match value {
+            "openssh" => Some(Self::OpenSsh),
+            "tailscale-ssh" => Some(Self::TailscaleSsh),
+            _ => None,
+        }
+    }
+}
+
+/// A connection profile. It contains routing metadata, never credentials.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub struct RemoteHost {
+    pub id: String,
+    pub label: String,
+    pub hostname: String,
+    pub username: Option<String>,
+    pub port: Option<u16>,
+    pub transport: RemoteTransport,
+}
+
+/// Where a workspace's processes and PTYs are owned.
+#[derive(Clone, Debug, Eq, PartialEq)]
+pub enum ExecutionTarget {
+    Local,
+    Remote {
+        host_id: String,
+        remote_path: String,
+    },
+}
+
 #[derive(Clone, Copy, Debug, Eq, PartialEq)]
 pub enum Platform {
     MacOs,
@@ -64,7 +114,7 @@ impl ProductStatus {
 
 #[cfg(test)]
 mod tests {
-    use super::{Platform, ProductStatus, UsageProvenance};
+    use super::{Platform, ProductStatus, RemoteTransport, UsageProvenance};
 
     #[test]
     fn scaffold_status_is_explicit() {
@@ -76,4 +126,14 @@ mod tests {
     fn usage_can_be_explicitly_unavailable() {
         assert_eq!(UsageProvenance::Unavailable, UsageProvenance::Unavailable);
     }
+
+    #[test]
+    fn remote_transport_storage_names_are_stable() {
+        for transport in [RemoteTransport::OpenSsh, RemoteTransport::TailscaleSsh] {
+            assert_eq!(
+                RemoteTransport::from_storage_name(transport.storage_name()),
+                Some(transport)
+            );
+        }
+    }
 }

crates/lumbridge-storage/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "lumbridge-storage"
+description = "Local SQLite persistence for Lumbridge"
+version.workspace = true
+edition.workspace = true
+rust-version.workspace = true
+license.workspace = true
+repository.workspace = true
+
+[dependencies]
+lumbridge-core = { path = "../lumbridge-core" }
+rusqlite = { version = "0.40.2", default-features = false, features = ["bundled"] }
+
+[lints]
+workspace = true

crates/lumbridge-storage/src/lib.rs

@@ -0,0 +1,284 @@
+//! Local, device-owned persistence for Lumbridge.
+//!
+//! This database stores workspace metadata and remote routing profiles. API
+//! keys, subscription credentials, SSH private keys, and Tailscale credentials
+//! are intentionally outside its contract.
+
+use std::path::Path;
+
+use lumbridge_core::{RemoteHost, RemoteTransport};
+use rusqlite::{Connection, OptionalExtension, params};
+
+const SCHEMA: &str = r"
+CREATE TABLE IF NOT EXISTS app_meta (
+    key TEXT PRIMARY KEY NOT NULL,
+    value TEXT NOT NULL
+) STRICT;
+
+INSERT INTO app_meta (key, value) VALUES ('schema_version', '2')
+ON CONFLICT(key) DO UPDATE SET value = excluded.value;
+
+CREATE TABLE IF NOT EXISTS remote_hosts (
+    id TEXT PRIMARY KEY NOT NULL,
+    label TEXT NOT NULL,
+    hostname TEXT NOT NULL,
+    username TEXT,
+    port INTEGER CHECK (port IS NULL OR port BETWEEN 1 AND 65535),
+    transport TEXT NOT NULL CHECK (transport IN ('openssh', 'tailscale-ssh')),
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+) STRICT;
+
+CREATE TABLE IF NOT EXISTS workspaces (
+    id TEXT PRIMARY KEY NOT NULL,
+    name TEXT NOT NULL,
+    repository_path TEXT,
+    remote_host_id TEXT REFERENCES remote_hosts(id) ON DELETE RESTRICT,
+    remote_path TEXT,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    CHECK (
+        (remote_host_id IS NULL AND remote_path IS NULL)
+        OR (remote_host_id IS NOT NULL AND remote_path IS NOT NULL)
+    )
+) STRICT;
+
+CREATE TABLE IF NOT EXISTS panes (
+    id TEXT PRIMARY KEY NOT NULL,
+    workspace_id TEXT NOT NULL REFERENCES workspaces(id) ON DELETE CASCADE,
+    kind TEXT NOT NULL,
+    title TEXT NOT NULL,
+    position INTEGER NOT NULL,
+    remote_session_id TEXT,
+    state_json TEXT NOT NULL DEFAULT '{}',
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+) STRICT;
+
+CREATE INDEX IF NOT EXISTS panes_workspace_position
+ON panes(workspace_id, position);
+
+CREATE TABLE IF NOT EXISTS buzz_accounts (
+    id TEXT PRIMARY KEY NOT NULL,
+    label TEXT NOT NULL,
+    relay_url TEXT NOT NULL,
+    public_key TEXT NOT NULL,
+    secret_store_handle TEXT NOT NULL,
+    created_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP,
+    updated_at TEXT NOT NULL DEFAULT CURRENT_TIMESTAMP
+) STRICT;
+
+CREATE TABLE IF NOT EXISTS workspace_buzz_channels (
+    workspace_id TEXT NOT NULL REFERENCES workspaces(id) ON DELETE CASCADE,
+    account_id TEXT NOT NULL REFERENCES buzz_accounts(id) ON DELETE CASCADE,
+    channel_id TEXT NOT NULL,
+    channel_name TEXT NOT NULL,
+    PRIMARY KEY (workspace_id, account_id, channel_id)
+) STRICT;
+";
+
+#[derive(Debug)]
+pub enum StorageError {
+    Database(rusqlite::Error),
+    UnknownTransport(String),
+}
+
+impl std::fmt::Display for StorageError {
+    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Database(error) => write!(formatter, "SQLite error: {error}"),
+            Self::UnknownTransport(value) => write!(formatter, "unknown remote transport: {value}"),
+        }
+    }
+}
+
+impl std::error::Error for StorageError {}
+
+impl From<rusqlite::Error> for StorageError {
+    fn from(error: rusqlite::Error) -> Self {
+        Self::Database(error)
+    }
+}
+
+pub type Result<T> = std::result::Result<T, StorageError>;
+
+/// The one `SQLite` connection owned by a runtime instance.
+pub struct Store {
+    connection: Connection,
+}
+
+impl Store {
+    /// Open or create a local database and apply forward-compatible migrations.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error when the file cannot be opened or its schema cannot be
+    /// initialized.
+    pub fn open(path: impl AsRef<Path>) -> Result<Self> {
+        Self::from_connection(Connection::open(path)?)
+    }
+
+    /// Create an isolated store for tests and short-lived tools.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error when `SQLite` cannot initialize the in-memory database.
+    pub fn open_in_memory() -> Result<Self> {
+        Self::from_connection(Connection::open_in_memory()?)
+    }
+
+    fn from_connection(connection: Connection) -> Result<Self> {
+        connection.execute_batch("PRAGMA foreign_keys = ON; PRAGMA busy_timeout = 5000;")?;
+        let mode: String =
+            connection.query_row("PRAGMA journal_mode = WAL", [], |row| row.get(0))?;
+        if mode == "wal" {
+            connection.execute_batch("PRAGMA synchronous = NORMAL;")?;
+        }
+        connection.execute_batch(SCHEMA)?;
+        Ok(Self { connection })
+    }
+
+    /// Return the currently installed schema version.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if the metadata table cannot be read.
+    pub fn schema_version(&self) -> Result<u32> {
+        let raw: String = self.connection.query_row(
+            "SELECT value FROM app_meta WHERE key = 'schema_version'",
+            [],
+            |row| row.get(0),
+        )?;
+        raw.parse()
+            .map_err(|_| StorageError::Database(rusqlite::Error::InvalidQuery))
+    }
+
+    /// Insert or update a credential-free remote host profile.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error if `SQLite` rejects the profile.
+    pub fn save_remote_host(&self, host: &RemoteHost) -> Result<()> {
+        self.connection.execute(
+            r"
+            INSERT INTO remote_hosts (id, label, hostname, username, port, transport)
+            VALUES (?1, ?2, ?3, ?4, ?5, ?6)
+            ON CONFLICT(id) DO UPDATE SET
+                label = excluded.label,
+                hostname = excluded.hostname,
+                username = excluded.username,
+                port = excluded.port,
+                transport = excluded.transport,
+                updated_at = CURRENT_TIMESTAMP
+            ",
+            params![
+                host.id,
+                host.label,
+                host.hostname,
+                host.username,
+                host.port,
+                host.transport.storage_name()
+            ],
+        )?;
+        Ok(())
+    }
+
+    /// Load one remote host profile by stable identifier.
+    ///
+    /// # Errors
+    ///
+    /// Returns an error when the row is malformed or cannot be read.
+    pub fn remote_host(&self, id: &str) -> Result<Option<RemoteHost>> {
+        let row = self
+            .connection
+            .query_row(
+                "SELECT id, label, hostname, username, port, transport FROM remote_hosts WHERE id = ?1",
+                [id],
+                |row| {
+                    Ok((
+                        row.get::<_, String>(0)?,
+                        row.get::<_, String>(1)?,
+                        row.get::<_, String>(2)?,
+                        row.get::<_, Option<String>>(3)?,
+                        row.get::<_, Option<u16>>(4)?,
+                        row.get::<_, String>(5)?,
+                    ))
+                },
+            )
+            .optional()?;
+
+        row.map(|(id, label, hostname, username, port, transport)| {
+            let transport = RemoteTransport::from_storage_name(&transport)
+                .ok_or_else(|| StorageError::UnknownTransport(transport.clone()))?;
+            Ok(RemoteHost {
+                id,
+                label,
+                hostname,
+                username,
+                port,
+                transport,
+            })
+        })
+        .transpose()
+    }
+
+    #[cfg(test)]
+    fn contains_column(&self, table: &str, column: &str) -> Result<bool> {
+        let mut statement = self
+            .connection
+            .prepare(&format!("PRAGMA table_info({table})"))?;
+        let names = statement.query_map([], |row| row.get::<_, String>(1))?;
+        for name in names {
+            if name? == column {
+                return Ok(true);
+            }
+        }
+        Ok(false)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use lumbridge_core::{RemoteHost, RemoteTransport};
+
+    use super::Store;
+
+    #[test]
+    fn initializes_schema_and_round_trips_remote_host() {
+        let store = Store::open_in_memory().expect("store should initialize");
+        assert_eq!(store.schema_version().expect("schema version"), 2);
+
+        let host = RemoteHost {
+            id: "metal".into(),
+            label: "metal · Jarvis".into(),
+            hostname: "desk-1-metal-jarvis.tail.example".into(),
+            username: Some("engineer".into()),
+            port: None,
+            transport: RemoteTransport::TailscaleSsh,
+        };
+        store.save_remote_host(&host).expect("host should save");
+        assert_eq!(
+            store.remote_host("metal").expect("host should load"),
+            Some(host)
+        );
+    }
+
+    #[test]
+    fn credential_columns_do_not_exist() {
+        let store = Store::open_in_memory().expect("store should initialize");
+        for forbidden in ["password", "private_key", "api_key", "auth_token"] {
+            assert!(
+                !store
+                    .contains_column("remote_hosts", forbidden)
+                    .expect("schema query")
+            );
+        }
+        for forbidden in ["private_key", "secret_key", "nsec", "auth_token"] {
+            assert!(
+                !store
+                    .contains_column("buzz_accounts", forbidden)
+                    .expect("schema query")
+            );
+        }
+    }
+}

docs/ARCHITECTURE.md

@@ -8,7 +8,8 @@ Lumbridge should be two cooperating Rust processes:
 native desktop UI
       | local authenticated IPC
 Lumbridge session runtime
-      |-- PTYs and process trees
+      |-- local PTYs and process trees
+      |-- SSH/Tailscale transport to remote Lumbridge runtimes
       |-- ACP clients and adapters
       |-- repositories and worktrees
       |-- usage/event ledger
@@ -30,13 +31,18 @@ messages should be real from the beginning.
 - `lumbridge-harness`: manifests, launch profiles, hooks, PTY fallback adapters.
 - `lumbridge-provider`: BYOK providers and provider-neutral usage records.
 - `lumbridge-storage`: SQLite migrations, event log, snapshots, retention.
+- `lumbridge-remote`: OpenSSH/Tailscale command construction, framed stdio,
+  handshake, reconnect, heartbeat, and remote-runtime discovery.
 - `lumbridge-secrets`: Keychain/libsecret adapters and redaction.
 - `lumbridge-git`: repositories, worktrees, diffs, status, conflict state.
+- `lumbridge-buzz`: credential-free Buzz event/broker preparation and pane-share
+  safety gates; platform adapters own signing and transport.
 - `lumbridge-ui`: native desktop state and rendering.
 - `lumbridge`: installable application entry point.
 
-Only `lumbridge-core` and the entry point exist in the scaffold. New crates are
+The scaffold currently contains `lumbridge-core`, `lumbridge-storage`,
-added after their architecture spike passes.
+`lumbridge-buzz`, and the entry point. Larger runtime crates are added after
+their architecture spikes pass.
 
 ## Terminal path
 
@@ -57,13 +63,46 @@ Do not lock the project to a webview or to Zed's private implementation details
 before a measured spike. Compare:
 
 1. GPUI for a Zed-like native model and excellent text-heavy interaction.
-2. Iced/wgpu plus a dedicated terminal renderer for stable Rust portability.
+2. Floem for an independent native Rust model with existing editor primitives.
-3. Tauri only as a delivery-speed baseline, not the assumed winner.
 
 The winner must render six busy panes smoothly, keep input latency low, support
 IME/accessibility, package on macOS and both Linux targets, and avoid a license
 or upstream-stability trap.
 
+## Local-first and remote session path
+
+SQLite is device-local. It stores workspace metadata, pane layouts, event and
+usage history, remote routing profiles, and small snapshots. It never stores SSH
+private keys, Tailscale credentials, provider API keys, or subscription tokens.
+Secrets remain in the OS credential store or in the user's existing SSH agent.
+
+A remote pane is not a local PTY wrapped around a long-lived `ssh` process. Its
+durable owner is a per-user `lumbridge-runtime` on the destination:
+
+```text
+MacBook Lumbridge UI/runtime
+       |
+       | ssh host lumbridge remote connect --stdio
+       | or: tailscale ssh host lumbridge remote connect --stdio
+       v
+remote per-user Lumbridge runtime -- Unix socket -- PTYs, agents, worktrees
+       |
+       `-- remote SQLite + chunked scrollback on that machine
+```
+
+The SSH child carries a versioned framed protocol over stdio. Normal OpenSSH
+remains the default because it honors the user's config, agent, host keys,
+ProxyJump, and Tailscale addresses. `tailscale ssh` is an explicit transport for
+users who want Tailscale's SSH proxy and host-key path. Lumbridge does not
+configure a tailnet, weaken ACLs, copy SSH keys, or require a listening TCP port.
+
+The remote runtime assigns a stable session ID before acknowledging a launch.
+On network loss the local pane becomes disconnected, the remote PTY continues,
+and reconnect resumes from the last acknowledged output sequence. A second
+authorized Lumbridge installation can attach to the same remote session after
+the remote runtime arbitrates input ownership. Collaborative simultaneous input
+is not part of the first release.
+
 ## Harness integration
 
 Each harness is described by a versioned manifest: executable discovery, launch
@@ -88,6 +127,14 @@ usually expose token counts but cost still depends on cached tokens, reasoning,
 tool calls, and current pricing. Adapters normalize facts without erasing their
 source or uncertainty.
 
+## Buzz collaboration
+
+Buzz channel messages, replies, agents, and attachments use the upstream Rust
+SDK's signed Nostr semantics. SQLite stores a public identity and opaque
+credential-store handle, never the private identity key. Pane images cross the
+network only after local capture, redaction preview, explicit destination, and
+confirmation. See `BUZZ_INTEGRATION.md` for the contract and test plan.
+
 ## Persistence
 
 SQLite in WAL mode stores metadata, commands/events, normalized usage, and small
@@ -95,6 +142,11 @@ snapshots. Large scrollback chunks and binary attachments use content-addressed
 files. A write-ahead event is committed before an external mutation is reported
 as accepted. Startup replays incomplete operations and reconciles live children.
 
+Default data roots are `~/Library/Application Support/ai.karti.lumbridge/` on
+macOS and `${XDG_DATA_HOME:-~/.local/share}/lumbridge/` on Linux. Backups and
+exports are explicit; Lumbridge does not synchronize the database through a
+hidden hosted account.
+
 ## Security
 
 - macOS secrets: Keychain; Linux secrets: Secret Service/libsecret, with an
@@ -113,4 +165,3 @@ Shared contracts cover PTY, process tree, notifications, secret store, paths,
 autostart, updater, and packaging. macOS uses `forkpty`/process groups and native
 Keychain. Ubuntu and Omarchy use Unix PTYs, cgroups/systemd scopes when available,
 and Secret Service. Omarchy is treated as Arch Linux, not as a separate kernel.
-

docs/BUZZ_INTEGRATION.md

@@ -0,0 +1,84 @@
+# Buzz integration
+
+## Product boundary
+
+Buzz is Lumbridge's first-class collaboration surface, not its control plane.
+Lumbridge remains useful offline, owns its local workspace state, and never
+requires a Buzz account to open a terminal or run an agent.
+
+The initial integration provides:
+
+- connect an existing Buzz identity using an OS credential-store reference;
+- bind one or more Buzz channels to a Lumbridge workspace;
+- read and post channel messages and replies from a collaboration pane;
+- surface Buzz agents attached to a bound channel without pretending they are
+  local processes;
+- share an approved pane image to an explicitly selected channel.
+
+## Protocol shape
+
+The pinned upstream is Block's Apache-2.0 Buzz repository at commit
+`cb3144999bebc4939cb15b2200b373281d493b52`. `buzz-sdk` constructs typed Nostr
+events and broker actions but deliberately owns neither identity keys nor
+network connections. Lumbridge follows that separation:
+
+```text
+Lumbridge collaboration pane
+       | typed local command
+lumbridge-buzz
+       | Buzz SDK event/broker action
+identity signer + Buzz transport adapter
+       | signed WebSocket / HTTPS upload
+Buzz relay and attachment storage
+```
+
+The exact revision stays pinned until an audited upgrade. We use Buzz's signed
+protocol and SDK types rather than a parallel webhook format.
+
+## Identity and local data
+
+SQLite stores the account label, relay URL, public key, and an opaque secret
+store handle. The Nostr private key stays in macOS Keychain or Linux Secret
+Service. It must never enter SQLite, command arguments, crash reports, pane
+history, logs, or Git configuration.
+
+An installed Buzz CLI identity may be imported only through an explicit user
+flow that transfers it into the OS credential store. Lumbridge must not search
+the filesystem for keys. Buzz's current NIP-AB device-pairing tooling is marked
+for interoperability testing upstream, so it is not a production login promise.
+
+## Pane-image sharing
+
+Sharing is a user-visible state machine:
+
+1. Capture the selected pane only, excluding application chrome by default.
+2. Detect likely secrets and render a local preview with proposed redactions.
+3. Let the user adjust redactions, caption, and destination channel.
+4. Require confirmation of that exact preview and destination.
+5. Encode PNG or WebP, hash it, upload with the authenticated Buzz attachment
+   flow, and receive a canonical URL.
+6. Build a kind-9 Buzz message with Markdown plus an `imeta` tag, sign it using
+   the OS-held identity, and publish it.
+7. Persist only the resulting event ID, attachment metadata, destination, and
+   local audit outcome. Never persist the unredacted capture.
+
+Any change to the pixels, caption, or destination invalidates confirmation. A
+failed upload or publish is retryable but never reported as sent.
+
+## Agent integration
+
+Buzz agents and Lumbridge harnesses are different entities. A Buzz agent may be
+shown in the collaboration pane and may exchange messages through Buzz's broker
+contract. A local or remote Lumbridge harness remains owned by the Lumbridge
+runtime and communicates through ACP or a supervised PTY. Linking the two later
+requires an explicit capability grant, visible identity, and revocation path.
+
+## Test plan
+
+- deterministic unit tests for channel IDs, content limits, media metadata, and
+  the review/confirmation gate;
+- signature tests with generated fixture identities only;
+- integration tests against a disposable local Buzz relay and attachment store;
+- disconnect, duplicate-delivery, cursor-resume, and publish-retry tests;
+- rendered tests proving destination and redactions remain visible at confirm;
+- a real-account smoke test only in a manually enabled, non-CI test profile.

docs/PRODUCT_SPEC.md

@@ -21,6 +21,24 @@ The product should feel faster and calmer as concurrency rises.
 5. Review file and Git changes by workspace or worktree.
 6. Understand usage, rate-limit windows, burn rate, and likely exhaustion time.
 7. Resume the entire workspace after the UI or machine restarts.
+8. Work from a laptop while selected panes and agents run durably on a
+   user-owned machine reached through SSH or Tailscale.
+9. Follow a project's Buzz channel and intentionally share a redacted pane image
+   without leaving the workspace.
+
+## Local and remote workspaces
+
+Every Lumbridge installation is useful on its own and owns its local settings,
+history, usage observations, and workspace views. A pane can execute locally or
+on a saved remote host. Remote hosts may be normal SSH destinations, entries in
+the user's SSH config, Tailscale MagicDNS names, or tailnet IPs.
+
+For durable remote work, a per-user Lumbridge runtime on the destination owns
+the PTY and process tree. The desktop app connects to that runtime over an SSH
+stdio channel and can later reconnect without moving the process to a cloud
+service. The same remote workspace may be opened from another authorized
+Lumbridge installation, but local UI state is not silently merged between
+devices.
 
 ## Initial harnesses
 
@@ -64,13 +82,23 @@ harness-reported, locally measured, estimated, or unavailable. Lumbridge must
 not scrape browser cookies or reverse-engineer private account APIs to manufacture
 an exact remaining balance. When only local observations exist, the UI says so.
 
+## Buzz collaboration
+
+Buzz is optional and deeply integrated: an engineer can connect an existing
+identity, bind channels to workspaces, read and send messages, see channel
+agents, and share a pane image. Sharing always previews the exact capture,
+redactions, caption, and destination before upload. Buzz identity secrets stay
+in the operating-system credential store.
+
 ## Non-goals for the first release
 
 - A new foundation-model training or inference service.
 - A hosted account or mandatory Lumbridge cloud.
 - Replacing every coding harness with one Lumbridge-owned agent loop.
 - Windows support.
-- Mobile control, collaborative cloud sessions, or remote execution.
+- Mobile control or collaborative hosted sessions.
+- Arbitrary third-party remote compute provisioning; the first release connects
+  only to machines and SSH/Tailscale access the user already controls.
 - Bundling third-party subscriptions or reselling model tokens.
 
 ## Experience principles
@@ -81,4 +109,3 @@ an exact remaining balance. When only local observations exist, the UI says so.
 - Approval and security boundaries stay visible.
 - Local and offline workflows remain useful.
 - Estimates are useful only when their uncertainty is honest.
-

docs/ROADMAP.md

@@ -4,9 +4,13 @@
 
 - Capture upstream snapshots, licenses, relevant modules, and architectural notes.
 - Benchmark UI candidates with six animated terminal panes.
+- Prove OpenSSH and `tailscale ssh` stdio transports against a disposable remote
+  runtime, including disconnect and replay.
 - Spike PTY correctness and process-tree cleanup on macOS, Ubuntu, and Omarchy.
 - Connect the official ACP Rust SDK to two contrasting harnesses.
 - Audit actual usage/quota surfaces for every launch provider.
+- Prove Buzz SDK message, attachment, cursor, reconnect, and duplicate-delivery
+  behavior against a disposable local relay.
 - Decide terminal core, UI stack, IPC transport, and schema evolution policy.
 
 Exit: recorded decisions with working spikes and measured results.
@@ -14,8 +18,12 @@ Exit: recorded decisions with working spikes and measured results.
 ## Phase 1 — terminal workspace alpha
 
 - Durable runtime, local IPC, workspaces, tabs, splits, shells, scrollback.
+- Saved SSH/Tailscale hosts and durable remote panes through a per-user remote
+  runtime; reconnect from a second Lumbridge installation.
 - Session restore, crash recovery, command palette, keybindings, notifications.
 - Repository/worktree creation and basic Git status/diff.
+- Optional Buzz collaboration pane, workspace channel binding, and confirmed
+  redacted pane-image sharing.
 - macOS, Ubuntu, and Omarchy development packages.
 
 Exit: Lumbridge is worth using as a terminal multiplexer without AI features.
@@ -44,4 +52,3 @@ Exit: usage displays are useful, auditable, and honest about uncertainty.
 - Signed/notarized macOS releases, `.deb`, AppImage, and Arch package.
 - Delta updater with signed manifests and rollback.
 - Accessibility, performance, soak, migration, and recovery qualification.
-

docs/UI_SPIKE_SCORECARD.md

@@ -0,0 +1,26 @@
+# Native UI spike scorecard
+
+The GPUI and Floem programs under `spikes/` consume the same six-pane fixture.
+No product framework decision is accepted until both rows contain measurements
+from macOS and Linux and the hard gates pass.
+
+| Criterion | Hard gate | GPUI | Floem |
+|---|---:|---:|---:|
+| Builds on macOS Apple Silicon | yes | pending | pending |
+| Builds on Ubuntu | yes | pending | pending |
+| Builds on Omarchy/Arch | yes | pending | pending |
+| Dependency/license closure permits Apache-2.0 distribution | yes | pending | pending |
+| Keyboard navigation + AccessKit tree | yes | pending | pending |
+| IME and composed Unicode input | yes | pending | pending |
+| Isolated system browser child | yes | pending | pending |
+| Cold startup, p50/p95 | record | pending | pending |
+| Idle RSS / six-stream RSS | record | pending | pending |
+| Key-to-present p50/p95 | record | pending | pending |
+| Six-stream frame p95/p99 | record | pending | pending |
+| Release binary/package size | record | pending | pending |
+| Native menu/window/clipboard/drag-and-drop | review | pending | pending |
+| API clarity and maintenance burden | review | pending | pending |
+
+The current programs establish dependency, build, launch, and static layout
+baselines. The next iteration adds deterministic streaming, input timestamps,
+accessibility identifiers, a native Markdown editor, and one Wry browser child.

docs/decisions/0003-local-data-and-remote-sessions.md

@@ -0,0 +1,25 @@
+# 0003: Data is local; remote sessions live on the user's remote machine
+
+Status: accepted for implementation.
+
+Each Lumbridge installation owns a local SQLite database and content-addressed
+data directory. There is no mandatory Lumbridge account, hosted database, or
+silent multi-device synchronization. Credentials remain in platform credential
+stores, SSH agents, or upstream harnesses rather than SQLite.
+
+Lumbridge supports local work and user-owned remote machines as equal execution
+targets. OpenSSH is the default transport and may reach a Tailscale MagicDNS name
+or tailnet address. An explicit `tailscale ssh` transport is also supported.
+Lumbridge consumes existing connectivity and authorization; it does not manage
+tailnet ACLs or private keys.
+
+Durability belongs where the process runs. A remote per-user Lumbridge runtime
+owns remote PTYs, agents, worktrees, event history, and scrollback. Desktop apps
+connect over a framed SSH stdio stream and reconnect by stable session ID. This
+allows a MacBook to close or change networks without terminating work on metal
+or amd-server.
+
+Another authorized Lumbridge installation may discover and attach to that remote
+workspace. Its device-local window layout and preferences remain local. The
+remote runtime arbitrates a single input owner in the first release; real-time
+collaborative editing is a separate future capability.

scripts/open-metal-bacon.sh

@@ -0,0 +1,44 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+repo_path=${LUMBRIDGE_REPO:-/home/metal/Desktop/Lumbridge Code/lumbridge}
+window_title='Lumbridge · Bacon'
+
+if [[ ! -d "$repo_path/.git" ]]; then
+  echo "Lumbridge repository not found at $repo_path" >&2
+  exit 1
+fi
+
+export DISPLAY=${DISPLAY:-:0}
+export XAUTHORITY=${XAUTHORITY:-/run/user/1000/gdm/Xauthority}
+
+for command_name in gnome-terminal wmctrl; do
+  if ! command -v "$command_name" >/dev/null 2>&1; then
+    echo "required command not found: $command_name" >&2
+    exit 1
+  fi
+done
+
+existing_id=$(wmctrl -l | awk -v title="$window_title" 'index($0, title) { print $1; exit }')
+if [[ -z "$existing_id" ]]; then
+  gnome-terminal \
+    --title="$window_title" \
+    -- bash -lc "cd '$repo_path' && source /home/metal/.cargo/env && exec bacon" &
+
+  for _attempt in $(seq 1 50); do
+    existing_id=$(wmctrl -l | awk -v title="$window_title" 'index($0, title) { print $1; exit }')
+    [[ -n "$existing_id" ]] && break
+    sleep 0.1
+  done
+fi
+
+if [[ -z "$existing_id" ]]; then
+  echo "Bacon terminal did not become visible" >&2
+  exit 1
+fi
+
+# Gigabyte G34WQC is 3440x1440 at X=0. Leave room for GNOME's top bar.
+wmctrl -i -r "$existing_id" -b remove,maximized_vert,maximized_horz
+wmctrl -i -r "$existing_id" -e 0,0,0,1720,1400
+wmctrl -i -a "$existing_id"
+echo "Bacon is running in window $existing_id on the left half of the Gigabyte display."

skills/lumbridge-development/SKILL.md

@@ -0,0 +1,53 @@
+---
+name: lumbridge-development
+description: Build, test, review, benchmark, or document Lumbridge, the native Rust local-first IDE, terminal multiplexer, and agent workspace.
+---
+
+# Lumbridge Development
+
+Work from the Lumbridge repository root. Read `AGENTS.md`, then only the product
+documents relevant to the task:
+
+- architecture or persistence: `docs/ARCHITECTURE.md` and `docs/decisions/`;
+- product behavior: `docs/PRODUCT_SPEC.md`;
+- tests: `docs/TESTING.md`;
+- native UI work: `docs/UI_OPTIONS.md` and `docs/UI_SPIKE_SCORECARD.md`;
+- Buzz work: `docs/BUZZ_INTEGRATION.md`.
+
+Preserve these product boundaries:
+
+- The application shell, terminal, editor, runtime, and state model are native
+  Rust. Do not introduce Electron, React, TypeScript, or a webview shell.
+- Data is local-first. SQLite contains metadata and history, never API keys,
+  subscription tokens, SSH private keys, Buzz private keys, or Tailscale keys.
+- Remote PTYs live in a per-user runtime on the user's remote machine. OpenSSH
+  and Tailscale are transports over access the user already configured; do not
+  change tailnet ACLs, copy credentials, or open public listeners.
+- macOS, Ubuntu, and Omarchy/Arch are release targets. A Linux-only success is
+  not cross-platform proof.
+- Usage and quota values always retain provenance and uncertainty.
+
+## Development loop
+
+Before editing, inspect Git status and preserve unrelated work. Use:
+
+```bash
+bacon
+cargo xtest
+./scripts/ci.sh
+```
+
+Root CI must remain independent from experimental UI dependencies. GPUI and
+Floem live in separate workspaces under `spikes/` and consume the same
+`ui-shell-model` fixture. Record only observed results in the scorecard; do not
+select a framework until both pass the hard gates.
+
+For Buzz integration, use its Apache-2.0 Rust SDK and signed protocol semantics
+rather than inventing a webhook dialect. Test against a local relay and fixture
+identity. Pane screenshots or transcripts require a visible preview, redaction,
+explicit destination, and user confirmation before upload.
+
+Add tests at the lowest deterministic layer first, then platform or rendered
+tests where behavior crosses a real boundary. Before handoff, run the relevant
+spike build plus `./scripts/ci.sh`, `git diff --check`, and report anything not
+validated on all target systems.

skills/lumbridge-development/agents/openai.yaml

@@ -0,0 +1,4 @@
+interface:
+  display_name: "Lumbridge Development"
+  short_description: "Build and validate the Lumbridge native IDE"
+  default_prompt: "Use $lumbridge-development to continue building and validating Lumbridge."

spikes/README.md

@@ -0,0 +1,37 @@
+# Native UI spikes
+
+These disposable applications render the same fixture through GPUI and Floem.
+They are a decision instrument, not product code. The root workspace excludes
+this nested workspace so normal Lumbridge CI does not download or compile both
+UI frameworks.
+
+The GPUI spike uses published `gpui 0.2.2`. The Floem spike pins upstream commit
+`778bb5f2aa08429e579ee2e6ac97e84fbf18b618`; the crates.io `floem 0.2.0` package
+lags the current API substantially enough that comparing it to current GPUI
+would not be representative.
+
+Both spikes must preserve the same information architecture:
+
+- workspace/sidebar and remote host state;
+- two rows of three busy surfaces;
+- local and remote terminal/agent panes;
+- native Markdown editor/preview and browser placeholders;
+- connection, harness, usage, and burn context in the footer.
+
+Build independently:
+
+```bash
+cargo build --release --manifest-path spikes/gpui-shell/Cargo.toml
+cargo build --release --manifest-path spikes/floem-shell/Cargo.toml
+```
+
+Each candidate is an independent Cargo workspace. GPUI pins `taffy 0.9.0`
+while current Floem requires `taffy 0.9.2`; putting them in one comparison
+workspace creates an artificial resolver conflict and would let one candidate's
+dependency decisions distort the other candidate's build.
+
+The comparison records release build time, binary size, startup, idle RSS,
+six-pane streaming frame time, key-to-present latency, accessibility/IME,
+window behavior, browser-child integration, packaging, dependency count, and
+license closure on macOS, Ubuntu, and Omarchy. A build is not adoption: GPUI's
+complete dependency-license closure remains a hard gate.

spikes/floem-shell/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "lumbridge-spike-floem"
+description = "Floem implementation of the Lumbridge native shell spike"
+version = "0.0.1"
+edition = "2024"
+rust-version = "1.94"
+license = "Apache-2.0"
+publish = false
+
+[dependencies]
+floem = { git = "https://github.com/lapce/floem", rev = "778bb5f2aa08429e579ee2e6ac97e84fbf18b618", default-features = false, features = ["vger"] }
+lumbridge-spike-model = { path = "../ui-shell-model" }
+
+[workspace]

spikes/floem-shell/src/main.rs

@@ -0,0 +1,163 @@
+use floem::{Application, kurbo::Size, peniko::Color, prelude::*, window::WindowConfig};
+use lumbridge_spike_model::{
+    FOOTER_CENTER, FOOTER_LEFT, FOOTER_RIGHT, PANES, PaneFixture, WORKSPACES,
+};
+
+const BG: Color = Color::from_rgb8(12, 14, 19);
+const PANEL: Color = Color::from_rgb8(18, 23, 34);
+const PANEL_ALT: Color = Color::from_rgb8(23, 29, 41);
+const BORDER: Color = Color::from_rgb8(41, 50, 68);
+const TEXT: Color = Color::from_rgb8(217, 226, 242);
+const MUTED: Color = Color::from_rgb8(127, 139, 163);
+const ACCENT: Color = Color::from_rgb8(119, 189, 251);
+
+fn pane_card(pane: PaneFixture) -> impl IntoView {
+    let header = Stack::horizontal((
+        Label::new(pane.title).style(|s| s.flex_grow(1.0).color(TEXT)),
+        Label::new(pane.badge).style(|s| s.font_size(11.0).color(ACCENT)),
+    ))
+    .style(|s| {
+        s.items_center()
+            .height(34.0)
+            .padding_horiz(10.0)
+            .background(PANEL_ALT)
+            .border_bottom(1.0)
+            .border_color(BORDER)
+    });
+
+    let lines =
+        Stack::vertical(pane.lines.map(|line| {
+            Label::new(line).style(|s| s.font_size(12.0).color(TEXT).margin_bottom(5.0))
+        }));
+
+    Stack::vertical((
+        header,
+        Label::new(pane.target).style(|s| s.font_size(11.0).color(MUTED).padding(10.0)),
+        lines.style(|s| s.padding_horiz(10.0).padding_bottom(10.0)),
+    ))
+    .style(|s| {
+        s.flex_basis(0)
+            .flex_grow(1.0)
+            .min_width(0.0)
+            .min_height(0.0)
+            .margin(4.0)
+            .background(PANEL)
+            .border(1.0)
+            .border_color(BORDER)
+            .border_radius(6.0)
+    })
+}
+
+fn app_view() -> impl IntoView {
+    let sidebar_items = Stack::vertical(WORKSPACES.map(|name| {
+        Label::new(name).style(move |s| {
+            s.width_full()
+                .padding_vert(8.0)
+                .padding_horiz(12.0)
+                .margin_bottom(3.0)
+                .color(if name == "Lumbridge Code" {
+                    TEXT
+                } else {
+                    MUTED
+                })
+                .apply_if(name == "Lumbridge Code", |s| {
+                    s.background(PANEL_ALT).border_radius(6.0)
+                })
+        })
+    }));
+
+    let sidebar = Stack::vertical((
+        Label::new("WORKSPACES").style(|s| s.font_size(11.0).color(MUTED).padding(12.0)),
+        sidebar_items.style(|s| s.padding_horiz(8.0)),
+        Label::new("HOSTS").style(|s| {
+            s.font_size(11.0)
+                .color(MUTED)
+                .padding(12.0)
+                .margin_top(12.0)
+        }),
+        Label::new("● metal · connected").style(|s| s.color(ACCENT).padding_horiz(14.0)),
+        Label::new("● amd-server · connected")
+            .style(|s| s.color(MUTED).padding_horiz(14.0).margin_top(8.0)),
+        Label::new("○ spark-1 · sleeping")
+            .style(|s| s.color(MUTED).padding_horiz(14.0).margin_top(8.0)),
+    ))
+    .style(|s| {
+        s.width(220.0)
+            .height_full()
+            .flex_shrink(0.0)
+            .background(PANEL)
+            .border_right(1.0)
+            .border_color(BORDER)
+    });
+
+    let top_row = Stack::horizontal((
+        pane_card(PANES[0]),
+        pane_card(PANES[1]),
+        pane_card(PANES[2]),
+    ))
+    .style(|s| s.flex_basis(0).flex_grow(1.0).min_height(0.0).width_full());
+    let bottom_row = Stack::horizontal((
+        pane_card(PANES[3]),
+        pane_card(PANES[4]),
+        pane_card(PANES[5]),
+    ))
+    .style(|s| s.flex_basis(0).flex_grow(1.0).min_height(0.0).width_full());
+    let panes = Stack::vertical((top_row, bottom_row)).style(|s| {
+        s.flex_basis(0)
+            .flex_grow(1.0)
+            .min_width(0.0)
+            .height_full()
+            .padding(4.0)
+    });
+
+    let header = Stack::horizontal((
+        Label::new("Lumbridge").style(|s| s.font_size(18.0).color(TEXT).flex_grow(1.0)),
+        Label::new("UI spike · Floem").style(|s| s.color(MUTED).flex_grow(1.0)),
+        Label::new("⌘K  Command Palette").style(|s| s.color(ACCENT)),
+    ))
+    .style(|s| {
+        s.height(46.0)
+            .padding_horiz(14.0)
+            .items_center()
+            .background(PANEL_ALT)
+            .border_bottom(1.0)
+            .border_color(BORDER)
+    });
+
+    let body = Stack::horizontal((sidebar, panes))
+        .style(|s| s.flex_basis(0).flex_grow(1.0).min_height(0.0));
+
+    let footer = Stack::horizontal((
+        Label::new(FOOTER_LEFT).style(|s| s.flex_grow(1.0)),
+        Label::new(FOOTER_CENTER).style(|s| s.flex_grow(1.0)),
+        Label::new(FOOTER_RIGHT),
+    ))
+    .style(|s| {
+        s.height(30.0)
+            .padding_horiz(10.0)
+            .items_center()
+            .font_size(11.0)
+            .color(MUTED)
+            .background(PANEL_ALT)
+            .border_top(1.0)
+            .border_color(BORDER)
+    });
+
+    Stack::vertical((header, body, footer))
+        .style(|s| s.width_full().height_full().background(BG))
+        .window_title(|| "Lumbridge · Floem spike".to_owned())
+}
+
+fn main() {
+    Application::new()
+        .window(
+            |_| app_view(),
+            Some(
+                WindowConfig::default()
+                    .size(Size::new(1280.0, 800.0))
+                    .min_size(Size::new(900.0, 600.0))
+                    .title("Lumbridge · Floem spike"),
+            ),
+        )
+        .run();
+}

spikes/gpui-shell/Cargo.toml

@@ -0,0 +1,14 @@
+[package]
+name = "lumbridge-spike-gpui"
+description = "GPUI implementation of the Lumbridge native shell spike"
+version = "0.0.1"
+edition = "2024"
+rust-version = "1.94"
+license = "Apache-2.0"
+publish = false
+
+[dependencies]
+gpui = "0.2.2"
+lumbridge-spike-model = { path = "../ui-shell-model" }
+
+[workspace]

spikes/gpui-shell/src/main.rs

@@ -0,0 +1,192 @@
+use gpui::{
+    App, Application, Bounds, Context, Window, WindowBounds, WindowOptions, div, prelude::*, px,
+    rgb, size,
+};
+use lumbridge_spike_model::{
+    FOOTER_CENTER, FOOTER_LEFT, FOOTER_RIGHT, PANES, PaneFixture, WORKSPACES,
+};
+
+const BG: u32 = 0x0c0e13;
+const PANEL: u32 = 0x121722;
+const PANEL_ALT: u32 = 0x171d29;
+const BORDER: u32 = 0x293244;
+const TEXT: u32 = 0xd9e2f2;
+const MUTED: u32 = 0x7f8ba3;
+const ACCENT: u32 = 0x77bdfb;
+
+struct LumbridgeShell;
+
+fn pane_card(pane: &PaneFixture) -> impl IntoElement {
+    div()
+        .flex()
+        .flex_col()
+        .min_w_0()
+        .min_h_0()
+        .overflow_hidden()
+        .bg(rgb(PANEL))
+        .border_1()
+        .border_color(rgb(BORDER))
+        .rounded_md()
+        .child(
+            div()
+                .flex()
+                .items_center()
+                .justify_between()
+                .px_3()
+                .h(px(34.0))
+                .bg(rgb(PANEL_ALT))
+                .border_b_1()
+                .border_color(rgb(BORDER))
+                .text_sm()
+                .text_color(rgb(TEXT))
+                .child(pane.title)
+                .child(div().text_xs().text_color(rgb(ACCENT)).child(pane.badge)),
+        )
+        .child(
+            div()
+                .px_3()
+                .py_2()
+                .text_xs()
+                .text_color(rgb(MUTED))
+                .child(pane.target),
+        )
+        .child(
+            div()
+                .flex()
+                .flex_col()
+                .gap_1()
+                .px_3()
+                .pb_3()
+                .text_sm()
+                .text_color(rgb(TEXT))
+                .children(pane.lines.into_iter()),
+        )
+}
+
+impl Render for LumbridgeShell {
+    fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
+        let sidebar = div()
+            .flex()
+            .flex_col()
+            .w(px(220.0))
+            .flex_none()
+            .bg(rgb(PANEL))
+            .border_r_1()
+            .border_color(rgb(BORDER))
+            .child(
+                div()
+                    .px_4()
+                    .py_3()
+                    .text_sm()
+                    .text_color(rgb(MUTED))
+                    .child("WORKSPACES"),
+            )
+            .children(WORKSPACES.into_iter().enumerate().map(|(index, name)| {
+                div()
+                    .mx_2()
+                    .mb_1()
+                    .px_3()
+                    .py_2()
+                    .rounded_md()
+                    .when(index == 0, |view| {
+                        view.bg(rgb(PANEL_ALT)).text_color(rgb(TEXT))
+                    })
+                    .when(index != 0, |view| view.text_color(rgb(MUTED)))
+                    .child(name)
+            }))
+            .child(
+                div()
+                    .mt_4()
+                    .px_4()
+                    .text_xs()
+                    .text_color(rgb(MUTED))
+                    .child("HOSTS")
+                    .child(
+                        div()
+                            .mt_2()
+                            .text_color(rgb(ACCENT))
+                            .child("● metal · connected"),
+                    )
+                    .child(div().mt_2().child("● amd-server · connected"))
+                    .child(div().mt_2().child("○ spark-1 · sleeping")),
+            );
+
+        let grid = div()
+            .grid()
+            .grid_cols(3)
+            .grid_rows(2)
+            .gap_2()
+            .p_2()
+            .size_full()
+            .children(PANES.iter().map(pane_card));
+
+        div()
+            .flex()
+            .flex_col()
+            .size_full()
+            .bg(rgb(BG))
+            .text_color(rgb(TEXT))
+            .child(
+                div()
+                    .flex()
+                    .items_center()
+                    .justify_between()
+                    .h(px(46.0))
+                    .flex_none()
+                    .px_4()
+                    .bg(rgb(PANEL_ALT))
+                    .border_b_1()
+                    .border_color(rgb(BORDER))
+                    .child(div().text_lg().child("Lumbridge"))
+                    .child(
+                        div()
+                            .text_sm()
+                            .text_color(rgb(MUTED))
+                            .child("UI spike · GPUI"),
+                    )
+                    .child(
+                        div()
+                            .text_sm()
+                            .text_color(rgb(ACCENT))
+                            .child("⌘K  Command Palette"),
+                    ),
+            )
+            .child(div().flex().flex_1().min_h_0().child(sidebar).child(grid))
+            .child(
+                div()
+                    .flex()
+                    .items_center()
+                    .justify_between()
+                    .h(px(30.0))
+                    .flex_none()
+                    .px_3()
+                    .bg(rgb(PANEL_ALT))
+                    .border_t_1()
+                    .border_color(rgb(BORDER))
+                    .text_xs()
+                    .text_color(rgb(MUTED))
+                    .child(FOOTER_LEFT)
+                    .child(FOOTER_CENTER)
+                    .child(FOOTER_RIGHT),
+            )
+    }
+}
+
+fn main() {
+    Application::new().run(|cx: &mut App| {
+        let bounds = Bounds::centered(None, size(px(1280.0), px(800.0)), cx);
+        cx.open_window(
+            WindowOptions {
+                window_bounds: Some(WindowBounds::Windowed(bounds)),
+                titlebar: Some(gpui::TitlebarOptions {
+                    title: Some("Lumbridge · GPUI spike".into()),
+                    ..Default::default()
+                }),
+                ..Default::default()
+            },
+            |_, cx| cx.new(|_| LumbridgeShell),
+        )
+        .expect("GPUI spike window should open");
+        cx.activate(true);
+    });
+}

spikes/ui-shell-model/Cargo.lock

@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "lumbridge-spike-model"
+version = "0.0.1"

spikes/ui-shell-model/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "lumbridge-spike-model"
+description = "Identical fixture data for Lumbridge native UI comparisons"
+version = "0.0.1"
+edition = "2024"
+rust-version = "1.94"
+license = "Apache-2.0"
+publish = false
+
+[lib]
+path = "src/lib.rs"
+
+[workspace]

spikes/ui-shell-model/src/lib.rs

@@ -0,0 +1,122 @@
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum SurfaceKind {
+    Terminal,
+    Markdown,
+    Browser,
+    Review,
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub struct PaneFixture {
+    pub title: &'static str,
+    pub badge: &'static str,
+    pub target: &'static str,
+    pub kind: SurfaceKind,
+    pub lines: [&'static str; 4],
+}
+
+pub const PANES: [PaneFixture; 6] = [
+    PaneFixture {
+        title: "Codex · runtime",
+        badge: "WORKING",
+        target: "metal · Tailscale SSH",
+        kind: SurfaceKind::Terminal,
+        lines: [
+            "$ cargo nextest run -p lumbridge-runtime",
+            "PASS remote::reconnect_replays_output",
+            "PASS pty::resize_preserves_cursor",
+            "agent is editing 3 files…",
+        ],
+    },
+    PaneFixture {
+        title: "Claude Code · UI",
+        badge: "NEEDS INPUT",
+        target: "MacBook Air · local",
+        kind: SurfaceKind::Terminal,
+        lines: [
+            "$ bacon clippy",
+            "finished in 0.42s",
+            "Which split should receive focus?",
+            "[Approve] [Steer] [Cancel]",
+        ],
+    },
+    PaneFixture {
+        title: "Pi · docs",
+        badge: "STREAMING",
+        target: "amd-server · OpenSSH",
+        kind: SurfaceKind::Terminal,
+        lines: [
+            "$ cargo watch --why",
+            "ACP session resumed at event 1842",
+            "writing remote-session.md",
+            "▌",
+        ],
+    },
+    PaneFixture {
+        title: "Architecture.md",
+        badge: "MARKDOWN",
+        target: "lumbridge-code · worktree",
+        kind: SurfaceKind::Markdown,
+        lines: [
+            "## Remote session path",
+            "The destination runtime owns the PTY.",
+            "The laptop may disconnect and reattach.",
+            "SQLite remains local to each machine.",
+        ],
+    },
+    PaneFixture {
+        title: "Preview · ACP docs",
+        badge: "BROWSER",
+        target: "isolated system web engine",
+        kind: SurfaceKind::Browser,
+        lines: [
+            "https://agentclientprotocol.com",
+            "Content process: sandboxed",
+            "Runtime bridge: no privileged access",
+            "Open in external browser  ↗",
+        ],
+    },
+    PaneFixture {
+        title: "Changes · lumbridge-runtime",
+        badge: "REVIEW",
+        target: "metal · worktree remote-runtime",
+        kind: SurfaceKind::Review,
+        lines: [
+            "+ 184  remote transport",
+            "+  96  SQLite migrations",
+            "−  12  obsolete scaffold",
+            "6 files · tests passing",
+        ],
+    },
+];
+
+pub const WORKSPACES: [&str; 5] = [
+    "Lumbridge Code",
+    "Runtime / metal",
+    "UI spikes",
+    "ACP adapters",
+    "Usage telemetry",
+];
+
+pub const FOOTER_LEFT: &str = "6 panes · 3 remote · 1 needs input";
+pub const FOOTER_CENTER: &str = "Codex · ChatGPT subscription · 62% window remaining";
+pub const FOOTER_RIGHT: &str = "burn 8.4%/hr · resets in 2h 14m";
+
+#[cfg(test)]
+mod tests {
+    use super::{PANES, SurfaceKind};
+
+    #[test]
+    fn comparison_fixture_has_six_mixed_surfaces() {
+        assert_eq!(PANES.len(), 6);
+        assert!(PANES.iter().any(|pane| pane.kind == SurfaceKind::Markdown));
+        assert!(PANES.iter().any(|pane| pane.kind == SurfaceKind::Browser));
+        assert_eq!(
+            PANES
+                .iter()
+                .filter(|pane| pane.kind == SurfaceKind::Terminal)
+                .count(),
+            3
+        );
+    }
+}