Phase 0: bootstrap Rust workspace

- Cargo workspace with 6 crates: shared, storaged, catalogd, queryd, aibridge, gateway
- shared: types (DatasetId, ObjectRef, SchemaFingerprint, DatasetManifest) + error enum
- gateway: Axum HTTP entrypoint with nested service routers + tracing
- All services expose /health stubs
- justfile with build/test/run recipes
- PRD, phase tracker, and ADR docs

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

crates/aibridge/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "aibridge"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+shared = { path = "../shared" }
+tokio = { workspace = true }
+axum = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tracing = { workspace = true }

crates/aibridge/src/lib.rs

@@ -0,0 +1 @@
+pub mod service;

crates/aibridge/src/service.rs

@@ -0,0 +1,9 @@
+use axum::{Router, routing::get};
+
+pub fn router() -> Router {
+    Router::new().route("/health", get(health))
+}
+
+async fn health() -> &'static str {
+    "aibridge ok"
+}

crates/catalogd/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "catalogd"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+shared = { path = "../shared" }
+tokio = { workspace = true }
+axum = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tracing = { workspace = true }

crates/catalogd/src/lib.rs

@@ -0,0 +1 @@
+pub mod service;

crates/catalogd/src/service.rs

@@ -0,0 +1,9 @@
+use axum::{Router, routing::get};
+
+pub fn router() -> Router {
+    Router::new().route("/health", get(health))
+}
+
+async fn health() -> &'static str {
+    "catalogd ok"
+}

crates/gateway/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "gateway"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+shared = { path = "../shared" }
+storaged = { path = "../storaged" }
+catalogd = { path = "../catalogd" }
+queryd = { path = "../queryd" }
+aibridge = { path = "../aibridge" }
+tokio = { workspace = true }
+axum = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true }
+tower-http = { workspace = true }

crates/gateway/src/main.rs

@@ -0,0 +1,29 @@
+use axum::{Router, routing::get};
+use tower_http::trace::TraceLayer;
+use tracing_subscriber::{EnvFilter, fmt, layer::SubscriberExt, util::SubscriberInitExt};
+
+#[tokio::main]
+async fn main() {
+    tracing_subscriber::registry()
+        .with(EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info")))
+        .with(fmt::layer())
+        .init();
+
+    let app = Router::new()
+        .route("/health", get(health))
+        .nest("/storage", storaged::service::router())
+        .nest("/catalog", catalogd::service::router())
+        .nest("/query", queryd::service::router())
+        .nest("/ai", aibridge::service::router())
+        .layer(TraceLayer::new_for_http());
+
+    let addr = "0.0.0.0:3100";
+    tracing::info!("gateway listening on {addr}");
+
+    let listener = tokio::net::TcpListener::bind(addr).await.unwrap();
+    axum::serve(listener, app).await.unwrap();
+}
+
+async fn health() -> &'static str {
+    "lakehouse ok"
+}

crates/queryd/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "queryd"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+shared = { path = "../shared" }
+tokio = { workspace = true }
+axum = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tracing = { workspace = true }

crates/queryd/src/lib.rs

@@ -0,0 +1 @@
+pub mod service;

crates/queryd/src/service.rs

@@ -0,0 +1,9 @@
+use axum::{Router, routing::get};
+
+pub fn router() -> Router {
+    Router::new().route("/health", get(health))
+}
+
+async fn health() -> &'static str {
+    "queryd ok"
+}

crates/shared/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "shared"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+serde = { workspace = true }
+serde_json = { workspace = true }
+thiserror = { workspace = true }
+uuid = { workspace = true }
+chrono = { workspace = true }

crates/shared/src/errors.rs

@@ -0,0 +1,35 @@
+use thiserror::Error;
+
+#[derive(Debug, Error)]
+pub enum LakehouseError {
+    #[error("dataset not found: {0}")]
+    DatasetNotFound(String),
+
+    #[error("object not found: {bucket}/{key}")]
+    ObjectNotFound { bucket: String, key: String },
+
+    #[error("storage error: {0}")]
+    Storage(String),
+
+    #[error("catalog error: {0}")]
+    Catalog(String),
+
+    #[error("query error: {0}")]
+    Query(String),
+
+    #[error("ai bridge error: {0}")]
+    AiBridge(String),
+
+    #[error("serialization error: {0}")]
+    Serialization(String),
+}
+
+impl LakehouseError {
+    pub fn status_code(&self) -> u16 {
+        match self {
+            Self::DatasetNotFound(_) | Self::ObjectNotFound { .. } => 404,
+            Self::Storage(_) | Self::Catalog(_) | Self::Query(_) | Self::AiBridge(_) => 500,
+            Self::Serialization(_) => 400,
+        }
+    }
+}

crates/shared/src/lib.rs

@@ -0,0 +1,2 @@
+pub mod types;
+pub mod errors;

crates/shared/src/types.rs

@@ -0,0 +1,42 @@
+use serde::{Deserialize, Serialize};
+use uuid::Uuid;
+
+/// Unique identifier for a dataset in the catalog.
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct DatasetId(pub Uuid);
+
+impl DatasetId {
+    pub fn new() -> Self {
+        Self(Uuid::new_v4())
+    }
+}
+
+impl std::fmt::Display for DatasetId {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.0)
+    }
+}
+
+/// Pointer to an object in storage. This is what the catalog stores — never raw data.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ObjectRef {
+    pub bucket: String,
+    pub key: String,
+    pub size_bytes: u64,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+}
+
+/// Schema fingerprint — deterministic hash of an Arrow schema.
+#[derive(Debug, Clone, PartialEq, Eq, Hash, Serialize, Deserialize)]
+pub struct SchemaFingerprint(pub String);
+
+/// Dataset manifest — the catalog's view of a dataset.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct DatasetManifest {
+    pub id: DatasetId,
+    pub name: String,
+    pub schema_fingerprint: SchemaFingerprint,
+    pub objects: Vec<ObjectRef>,
+    pub created_at: chrono::DateTime<chrono::Utc>,
+    pub updated_at: chrono::DateTime<chrono::Utc>,
+}

crates/storaged/Cargo.toml

@@ -0,0 +1,12 @@
+[package]
+name = "storaged"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+shared = { path = "../shared" }
+tokio = { workspace = true }
+axum = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+tracing = { workspace = true }

crates/storaged/src/lib.rs

@@ -0,0 +1 @@
+pub mod service;

crates/storaged/src/service.rs

@@ -0,0 +1,9 @@
+use axum::{Router, routing::get};
+
+pub fn router() -> Router {
+    Router::new().route("/health", get(health))
+}
+
+async fn health() -> &'static str {
+    "storaged ok"
+}