6 files changed, 506 insertions, 0 deletions
diff --git a/crates/daemon/src/api/client/mod.rs b/crates/daemon/src/api/client/mod.rs
new file mode 100644
index 00000000..d6cbbe85
--- /dev/null
+++ b/crates/daemon/src/api/client/mod.rs
@@ -0,0 +1,180 @@
+use eyre::{Context as EyreContext, Result};
+use tonic::Code;
+use tonic::transport::{Channel, Endpoint, Uri};
+use tower::service_fn;
+
+use hyper_util::rt::TokioIo;
+
+#[cfg(unix)]
+use tokio::net::UnixStream;
+
+use crate::{
+    aclient::{history::History, settings::Settings},
+    api::{
+        DAEMON_PROTOCOL_VERSION, DAEMON_VERSION,
+        generated::{
+            control::{
+                StatusReply, StatusRequest, control_client::ControlClient as ControlServiceClient,
+            },
+            history::{
+                EndHistoryReply, EndHistoryRequest, StartHistoryReply, StartHistoryRequest,
+                TailHistoryReply, TailHistoryRequest,
+                history_client::HistoryClient as HistoryServiceClient,
+            },
+        },
+    },
+};
+
+fn daemon_matches_expected(version: &str, protocol: u32) -> bool {
+    version == DAEMON_VERSION && protocol == DAEMON_PROTOCOL_VERSION
+}
+
+fn daemon_mismatch_message(version: &str, protocol: u32) -> String {
+    if protocol == DAEMON_PROTOCOL_VERSION {
+        format!("daemon is out of date: expected {DAEMON_VERSION}, got {version}")
+    } else {
+        format!("daemon protocol mismatch: expected {DAEMON_PROTOCOL_VERSION}, got {protocol}")
+    }
+}
+
+#[derive(Clone, Copy, Debug, Eq, PartialEq)]
+pub enum DaemonClientErrorKind {
+    Connect,
+    Unavailable,
+    Unimplemented,
+    Other,
+}
+
+#[must_use]
+pub fn classify_error(error: &eyre::Report) -> DaemonClientErrorKind {
+    for cause in error.chain() {
+        if cause.downcast_ref::<tonic::transport::Error>().is_some() {
+            return DaemonClientErrorKind::Connect;
+        }
+
+        if let Some(status) = cause.downcast_ref::<tonic::Status>() {
+            return match status.code() {
+                Code::Unavailable => DaemonClientErrorKind::Unavailable,
+                Code::Unimplemented => DaemonClientErrorKind::Unimplemented,
+                _ => DaemonClientErrorKind::Other,
+            };
+        }
+    }
+
+    DaemonClientErrorKind::Other
+}
+
+// ============================================================================
+// History Client
+// ============================================================================
+
+pub struct HistoryClient {
+    client: HistoryServiceClient<Channel>,
+}
+
+// Wrap the grpc client
+impl HistoryClient {
+    #[cfg(unix)]
+    pub async fn new(path: String) -> Result<Self> {
+        use eyre::Context;
+
+        let log_path = path.clone();
+        let channel = Endpoint::try_from("http://atuin_local_daemon:0")?
+            .connect_with_connector(service_fn(move |_: Uri| {
+                let path = path.clone();
+
+                async move {
+                    Ok::<_, std::io::Error>(TokioIo::new(UnixStream::connect(path.clone()).await?))
+                }
+            }))
+            .await
+            .wrap_err_with(|| {
+                format!(
+                    "failed to connect to local atuin daemon at {}. Is it running?",
+                    &log_path
+                )
+            })?;
+
+        let client = HistoryServiceClient::new(channel);
+
+        Ok(Self { client })
+    }
+
+    pub async fn start_history(&mut self, h: History) -> Result<StartHistoryReply> {
+        let req = StartHistoryRequest {
+            command: h.command,
+            cwd: h.cwd,
+            hostname: h.hostname,
+            session: h.session,
+            timestamp: h.timestamp.unix_timestamp_nanos() as u64,
+            author: h.author,
+            intent: h.intent.unwrap_or_default(),
+        };
+
+        Ok(self.client.start_history(req).await?.into_inner())
+    }
+
+    pub async fn end_history(
+        &mut self,
+        id: String,
+        duration: u64,
+        exit: i64,
+    ) -> Result<EndHistoryReply> {
+        let req = EndHistoryRequest { id, exit, duration };
+
+        Ok(self.client.end_history(req).await?.into_inner())
+    }
+
+    pub(crate) async fn tail_history(&mut self) -> Result<tonic::Streaming<TailHistoryReply>> {
+        Ok(self
+            .client
+            .tail_history(TailHistoryRequest {})
+            .await?
+            .into_inner())
+    }
+}
+
+// ============================================================================
+// Control Client
+// ============================================================================
+
+/// Client for the Control gRPC service.
+pub struct ControlClient {
+    client: ControlServiceClient<Channel>,
+}
+
+impl ControlClient {
+    /// Connect to the daemon's control service.
+    pub(crate) async fn new(path: String) -> Result<Self> {
+        let log_path = path.clone();
+        let channel = Endpoint::try_from("http://atuin_local_daemon:0")?
+            .connect_with_connector(service_fn(move |_: Uri| {
+                let path = path.clone();
+
+                async move {
+                    Ok::<_, std::io::Error>(TokioIo::new(UnixStream::connect(path.clone()).await?))
+                }
+            }))
+            .await
+            .wrap_err_with(|| {
+                format!(
+                    "failed to connect to local atuin daemon at {}. Is it running?",
+                    &log_path
+                )
+            })?;
+
+        let client = ControlServiceClient::new(channel);
+
+        Ok(Self { client })
+    }
+
+    /// Connect using settings.
+    #[cfg(unix)]
+    pub async fn from_settings(settings: &Settings) -> Result<Self> {
+        Self::new(settings.daemon.socket_path.clone()).await
+    }
+
+    pub async fn status(&mut self) -> Result<StatusReply> {
+        Ok(self.client.status(StatusRequest {}).await?.into_inner())
+    }
+}
diff --git a/crates/daemon/src/api/generated.rs b/crates/daemon/src/api/generated.rs
new file mode 100644
index 00000000..304edcd9
--- /dev/null
+++ b/crates/daemon/src/api/generated.rs
@@ -0,0 +1,28 @@
+#![expect(
+    unreachable_pub,
+    unused_qualifications,
+    clippy::doc_markdown,
+    clippy::default_trait_access,
+    clippy::too_many_lines,
+    clippy::trivially_copy_pass_by_ref,
+    clippy::allow_attributes,
+    clippy::derive_partial_eq_without_eq,
+    reason = "All of these lints are triggered by the generated code"
+)]
+
+/// Semantic command capture gRPC service types.
+pub(crate) mod semantic {
+    tonic::include_proto!("semantic");
+}
+
+/// History module for the daemon gRPC history service.
+///
+/// This module contains the proto-generated types for the history gRPC service.
+pub(crate) mod history {
+    tonic::include_proto!("history");
+}
+
+/// Control module for external control.
+pub(crate) mod control {
+    tonic::include_proto!("control");
+}
diff --git a/crates/daemon/src/api/mod.rs b/crates/daemon/src/api/mod.rs
new file mode 100644
index 00000000..e6f8f1f0
--- /dev/null
+++ b/crates/daemon/src/api/mod.rs
@@ -0,0 +1,6 @@
+pub(crate) mod client;
+pub(crate) mod server;
+pub(crate) mod generated;
+
+const DAEMON_VERSION: &str = env!("CARGO_PKG_VERSION");
+const DAEMON_PROTOCOL_VERSION: u32 = 1;
diff --git a/crates/daemon/src/api/server/control.rs b/crates/daemon/src/api/server/control.rs
new file mode 100644
index 00000000..63fef340
--- /dev/null
+++ b/crates/daemon/src/api/server/control.rs
@@ -0,0 +1,61 @@
+use tonic::{Request, Response, Status};
+use tracing::{Level, instrument};
+
+use crate::{
+    api::{
+        DAEMON_PROTOCOL_VERSION, DAEMON_VERSION,
+        generated::control::{
+            ForceSyncReply, ForceSyncRequest, StatusReply, StatusRequest,
+            control_server::{Control, ControlServer},
+        },
+    },
+    daemon::DaemonHandle,
+};
+
+/// The Control gRPC service.
+///
+/// This service is used by external processes to inject events into the daemon.
+/// It's not a component - it's part of the daemon's core infrastructure.
+pub(crate) struct ControlService {
+    handle: DaemonHandle,
+}
+
+impl ControlService {
+    /// Create a new control service with the given daemon handle.
+    pub(crate) fn new(handle: DaemonHandle) -> Self {
+        Self { handle }
+    }
+
+    /// Get a tonic server for this service.
+    pub(crate) fn into_server(self) -> ControlServer<Self> {
+        ControlServer::new(self)
+    }
+}
+
+#[tonic::async_trait]
+impl Control for ControlService {
+    #[instrument(skip_all, level = Level::INFO)]
+    async fn status(
+        &self,
+        _request: Request<StatusRequest>,
+    ) -> Result<Response<StatusReply>, Status> {
+        let reply = StatusReply {
+            healthy: true,
+            version: DAEMON_VERSION.to_owned(),
+            pid: std::process::id(),
+            protocol: DAEMON_PROTOCOL_VERSION,
+        };
+
+        Ok(Response::new(reply))
+    }
+
+    #[instrument(skip_all, level = Level::INFO)]
+    async fn force_sync(
+        &self,
+        _request: Request<ForceSyncRequest>,
+    ) -> Result<Response<ForceSyncReply>, Status> {
+        let reply = ForceSyncReply { accepted: false };
+
+        Ok(Response::new(reply))
+    }
+}
diff --git a/crates/daemon/src/api/server/history.rs b/crates/daemon/src/api/server/history.rs
new file mode 100644
index 00000000..032876a6
--- /dev/null
+++ b/crates/daemon/src/api/server/history.rs
@@ -0,0 +1,229 @@
+use std::pin::Pin;
+
+use dashmap::DashMap;
+use eyre::Result;
+use time::OffsetDateTime;
+use tokio_stream::Stream;
+use tonic::{Request, Response, Status};
+use tracing::{Level, instrument};
+
+use crate::{
+    aclient::history::{History, HistoryId, store::HistoryStore},
+    api::{
+        DAEMON_PROTOCOL_VERSION,
+        generated::history::{
+            EndHistoryReply, EndHistoryRequest, HistoryEntry, HistoryEventKind, StartHistoryReply,
+            StartHistoryRequest, TailHistoryReply, TailHistoryRequest,
+            history_server::History as HistorySvc,
+        },
+    },
+    daemon::DaemonHandle,
+    events::DaemonEvent,
+};
+
+/// The gRPC service implementation.
+///
+/// This is a thin wrapper that delegates to the component's shared state.
+pub(crate) struct HistoryGrpcService {
+    /// Commands currently running (not yet completed).
+    running: DashMap<HistoryId, History>,
+
+    /// Handle to the daemon (set during start).
+    pub(crate) handle: tokio::sync::RwLock<Option<DaemonHandle>>,
+
+    /// History store for pushing records (set during start).
+    pub(crate) history_store: tokio::sync::RwLock<Option<HistoryStore>>,
+}
+
+impl HistoryGrpcService {
+    /// Create a new history component.
+    pub(crate) fn new() -> Self {
+        Self {
+            running: DashMap::new(),
+            handle: tokio::sync::RwLock::new(None),
+            history_store: tokio::sync::RwLock::new(None),
+        }
+    }
+}
+
+fn history_to_tail_reply(kind: HistoryEventKind, history: History) -> TailHistoryReply {
+    TailHistoryReply {
+        kind: kind as i32,
+        history: Some(HistoryEntry {
+            timestamp: history.timestamp.unix_timestamp_nanos() as u64,
+            id: history.id.0,
+            command: history.command,
+            cwd: history.cwd,
+            session: history.session,
+            hostname: history.hostname,
+            author: history.author,
+            intent: history.intent.unwrap_or_default(),
+            exit: history.exit,
+            duration: history.duration,
+        }),
+    }
+}
+
+#[tonic::async_trait]
+impl HistorySvc for HistoryGrpcService {
+    type TailHistoryStream = Pin<Box<dyn Stream<Item = Result<TailHistoryReply, Status>> + Send>>;
+
+    #[instrument(skip_all, level = Level::INFO)]
+    async fn start_history(
+        &self,
+        request: Request<StartHistoryRequest>,
+    ) -> Result<Response<StartHistoryReply>, Status> {
+        let req = request.into_inner();
+
+        let timestamp = OffsetDateTime::from_unix_timestamp_nanos(i128::from(req.timestamp))
+            .map_err(|_| {
+                Status::invalid_argument(
+                    "failed to parse timestamp as unix time (expected nanos since epoch)",
+                )
+            })?;
+
+        let h: History = History::daemon()
+            .timestamp(timestamp)
+            .command(req.command)
+            .cwd(req.cwd)
+            .session(req.session)
+            .hostname(req.hostname)
+            .author(req.author)
+            .intent(req.intent)
+            .build()
+            .into();
+
+        // Emit the event
+        if let Some(handle) = self.handle.read().await.as_ref() {
+            handle.emit(DaemonEvent::HistoryStarted(h.clone()));
+        }
+
+        let id = h.id.clone();
+        tracing::info!(id = id.to_string(), "start history");
+        self.running.insert(id.clone(), h);
+
+        let reply = StartHistoryReply {
+            id: id.to_string(),
+            version: env!("CARGO_PKG_VERSION").to_string(),
+            protocol: DAEMON_PROTOCOL_VERSION,
+        };
+
+        Ok(Response::new(reply))
+    }
+
+    #[instrument(skip_all, level = Level::INFO)]
+    #[expect(clippy::significant_drop_tightening, reason = "Would be a logic-bug")]
+    async fn end_history(
+        &self,
+        request: Request<EndHistoryRequest>,
+    ) -> Result<Response<EndHistoryReply>, Status> {
+        let req = request.into_inner();
+        let id = HistoryId(req.id);
+
+        if let Some((_, mut history)) = self.running.remove(&id) {
+            history.exit = req.exit;
+            history.duration = match req.duration {
+                0 => i64::try_from(
+                    (OffsetDateTime::now_utc() - history.timestamp).whole_nanoseconds(),
+                )
+                .expect("failed to convert calculated duration to i64"),
+                value => i64::try_from(value).expect("failed to get i64 duration"),
+            };
+
+            // Get the handle and store to save the history
+            let handle_guard = self.handle.read().await;
+            let handle = handle_guard
+                .as_ref()
+                .ok_or_else(|| Status::internal("component not initialized"))?;
+
+            let store_guard = self.history_store.read().await;
+            let history_store = store_guard
+                .as_ref()
+                .ok_or_else(|| Status::internal("component not initialized"))?;
+
+            // Save to database
+            handle
+                .history_db()
+                .save(&history)
+                .await
+                .map_err(|e| Status::internal(format!("failed to write to db: {e:?}")))?;
+
+            tracing::info!(id = id.0, duration = history.duration, "end history");
+
+            // Push to record store
+            let (record_id, idx) = history_store
+                .push(history.clone())
+                .await
+                .map_err(|e| Status::internal(format!("failed to push record to store: {e:?}")))?;
+
+            // Emit the event
+            handle.emit(DaemonEvent::HistoryEnded(history));
+
+            let reply = EndHistoryReply {
+                id: record_id.0.to_string(),
+                idx,
+                version: env!("CARGO_PKG_VERSION").to_string(),
+                protocol: DAEMON_PROTOCOL_VERSION,
+            };
+
+            return Ok(Response::new(reply));
+        }
+
+        Err(Status::not_found(format!(
+            "could not find history with id: {id}"
+        )))
+    }
+
+    #[instrument(skip_all, level = Level::INFO)]
+    #[expect(clippy::significant_drop_tightening, reason = "Would be a logic-bug")]
+    async fn tail_history(
+        &self,
+        _request: Request<TailHistoryRequest>,
+    ) -> Result<Response<Self::TailHistoryStream>, Status> {
+        let handle_guard = self.handle.read().await;
+        let handle = handle_guard
+            .as_ref()
+            .cloned()
+            .ok_or_else(|| Status::internal("component not initialized"))?;
+
+        let mut rx = handle.subscribe();
+        let (tx, out_rx) = tokio::sync::mpsc::channel::<Result<TailHistoryReply, Status>>(128);
+
+        tokio::spawn(async move {
+            loop {
+                let event = match rx.recv().await {
+                    Ok(event) => event,
+                    Err(tokio::sync::broadcast::error::RecvError::Lagged(skipped)) => {
+                        drop(
+                            tx.send(Err(Status::resource_exhausted(format!(
+                                "tail stream lagged behind and dropped {skipped} events"
+                            ))))
+                            .await,
+                        );
+                        break;
+                    }
+                    Err(tokio::sync::broadcast::error::RecvError::Closed) => break,
+                };
+
+                let reply = match event {
+                    DaemonEvent::HistoryStarted(history) => {
+                        Some(history_to_tail_reply(HistoryEventKind::Started, history))
+                    }
+                    DaemonEvent::HistoryEnded(history) => {
+                        Some(history_to_tail_reply(HistoryEventKind::Ended, history))
+                    }
+                    _ => None,
+                };
+
+                if let Some(reply) = reply
+                    && tx.send(Ok(reply)).await.is_err()
+                {
+                    break;
+                }
+            }
+        });
+
+        let stream = tokio_stream::wrappers::ReceiverStream::new(out_rx);
+        Ok(Response::new(Box::pin(stream)))
+    }
+}
diff --git a/crates/daemon/src/api/server/mod.rs b/crates/daemon/src/api/server/mod.rs
new file mode 100644
index 00000000..8d475fe9
--- /dev/null
+++ b/crates/daemon/src/api/server/mod.rs
@@ -0,0 +1,2 @@
+pub(crate) mod control;
+pub(crate) mod history;