diff --git a/bao/bao.go b/bao/bao.go
index 4de5869..899bc31 100644
--- a/bao/bao.go
+++ b/bao/bao.go
@@ -23,6 +23,7 @@ type Bao interface {
 	Write(id uint32, data []byte) error
 	Finalize(id uint32) ([]byte, error)
 	Destroy(id uint32) error
+	ComputeFile(path string) ([]byte, error)
 }
 
 func init() {
@@ -88,8 +89,7 @@ func init() {
 
 }
 
-func ComputeBaoTree(reader io.Reader) ([]byte, error) {
-
+func ComputeTreeStreaming(reader io.Reader) ([]byte, error) {
 	instance, err := baoInstance.Init()
 	if err != nil {
 		return nil, err
@@ -119,6 +119,15 @@ func ComputeBaoTree(reader io.Reader) ([]byte, error) {
 	}
 }
 
+func ComputeTreeFile(file *os.File) ([]byte, error) {
+	tree, err := baoInstance.ComputeFile(file.Name())
+	if err != nil {
+		return nil, err
+	}
+
+	return tree, nil
+}
+
 func write(instance uint32, bytes *[]byte) error {
 	err := baoInstance.Write(instance, *bytes)
 	if err != nil {
diff --git a/bao/client.go b/bao/client.go
index 784f046..b490f26 100644
--- a/bao/client.go
+++ b/bao/client.go
@@ -45,3 +45,11 @@ func (g *GRPCClient) Destroy(id uint32) error {
 
 	return nil
 }
+func (g *GRPCClient) ComputeFile(path string) ([]byte, error) {
+	tree, err := g.client.ComputeFile(context.Background(), &wrappers.StringValue{Value: path})
+	if err != nil {
+		return nil, err
+	}
+
+	return tree.Value, nil
+}
diff --git a/bao/proto/bao.proto b/bao/proto/bao.proto
index 861a4ca..7c09ec3 100644
--- a/bao/proto/bao.proto
+++ b/bao/proto/bao.proto
@@ -17,4 +17,5 @@ service bao {
     rpc Write(WriteRequest) returns (google.protobuf.Empty);
     rpc Finalize (google.protobuf.UInt32Value) returns (google.protobuf.BytesValue);
     rpc Destroy (google.protobuf.UInt32Value) returns (google.protobuf.Empty);
+    rpc ComputeFile (google.protobuf.StringValue) returns (google.protobuf.BytesValue);
 }
diff --git a/bao/src/main.rs b/bao/src/main.rs
index 05c65db..ac162de 100644
--- a/bao/src/main.rs
+++ b/bao/src/main.rs
@@ -1,8 +1,11 @@
 #![feature(async_fn_in_trait)]
 #![allow(incomplete_features)]
 
+use io::Read;
 use std::collections::hash_map::Entry;
 use std::collections::HashMap;
+use std::fs::{File};
+use std::io;
 use std::io::{Cursor, Write};
 use std::sync::{Arc};
 
@@ -16,7 +19,7 @@ use tonic_health::server::HealthReporter;
 
 use crate::proto::bao::bao_server::{Bao, BaoServer};
 use crate::proto::bao::WriteRequest;
-use crate::proto::google::protobuf::{BytesValue, Empty, UInt32Value};
+use crate::proto::google::protobuf::{BytesValue, Empty, StringValue, UInt32Value};
 use crate::unique_port::UniquePort;
 
 mod proto;
@@ -64,7 +67,7 @@ impl Bao for BaoService {
         let next_id = self.counter.inc() as u32;
         let tree = Vec::new();
         let cursor = Cursor::new(tree);
-        let encoder = Encoder::new(cursor);
+        let encoder = Encoder::new_outboard(cursor);
 
         let mut req = self.requests.lock();
         req.insert(next_id, encoder);
@@ -113,4 +116,36 @@ impl Bao for BaoService {
 
         Ok(Response::new(Empty::default()))
     }
+
+    async fn compute_file(&self, request: Request<StringValue>) -> Result<Response<BytesValue>, Status> {
+        let r = request.into_inner();
+        let tree = Vec::new();
+        let cursor = Cursor::new(tree);
+        let mut encoder = Encoder::new_outboard(cursor);
+        let mut input =  File::open(r.value)?;
+
+        copy_reader_to_writer(&mut input, &mut encoder)?;
+
+        let ret = encoder.finalize().unwrap();
+        let bytes = ret.as_bytes().to_vec();
+        Ok(Response::new(BytesValue { value: bytes }))
+    }
+}
+fn copy_reader_to_writer(
+    reader: &mut impl Read,
+    writer: &mut impl Write,
+) -> io::Result<u64> {
+    // At least 16 KiB is necessary to use AVX-512 with BLAKE3.
+    let mut buf = [0; 65536];
+    let mut written = 0;
+    loop {
+        let len = match reader.read(&mut buf) {
+            Ok(0) => return Ok(written),
+            Ok(len) => len,
+            Err(ref e) if e.kind() == io::ErrorKind::Interrupted => continue,
+            Err(e) => return Err(e),
+        };
+        writer.write_all(&buf[..len])?;
+        written += len as u64;
+    }
 }