diff --git a/src/content/read.rs b/src/content/read.rs
index 854c6b3..a5d0adb 100644
--- a/src/content/read.rs
+++ b/src/content/read.rs
@@ -1,23 +1,30 @@
-use crate::content::path;
-use ssri::Integrity;
+use std::fs;
 use std::path::Path;
-use std::fs::{self, File};
-use std::io;
 
-pub fn open(cache: &Path, sri: &Integrity) -> io::Result<File> {
-    File::open(path::content_path(&cache, &sri))
+use ssri::Integrity;
+
+use crate::content::path;
+use crate::errors::Error;
+
+pub fn read(cache: &Path, sri: &Integrity) -> Result<Vec<u8>, Error> {
+    let cpath = path::content_path(&cache, &sri);
+    let ret = fs::read(&cpath)?;
+    if sri.clone().check(&ret).is_some() {
+        Ok(ret)
+    } else {
+        Err(Error::IntegrityError)
+    }
 }
 
-pub fn read(cache: &Path, sri: &Integrity) -> io::Result<Vec<u8>> {
-    fs::read(path::content_path(&cache, &sri))
-}
-
-pub fn read_to_string(cache: &Path, sri: &Integrity) -> io::Result<String> {
-    fs::read_to_string(path::content_path(&cache, &sri))
-}
-
-pub fn copy(cache: &Path, sri: &Integrity, to: &Path) -> io::Result<u64> {
-    fs::copy(path::content_path(&cache, &sri), to)
+pub fn copy(cache: &Path, sri: &Integrity, to: &Path) -> Result<u64, Error> {
+    let cpath = path::content_path(&cache, &sri);
+    let ret = fs::copy(&cpath, to)?;
+    let data = fs::read(cpath)?;
+    if sri.clone().check(data).is_some() {
+        Ok(ret)
+    } else {
+        Err(Error::IntegrityError)
+    }
 }
 
 pub fn has_content(cache: &Path, sri: &Integrity) -> Option<Integrity> {
diff --git a/src/errors.rs b/src/errors.rs
index 5138f49..ecadcfa 100644
--- a/src/errors.rs
+++ b/src/errors.rs
@@ -6,6 +6,10 @@ use serde_json;
 
 #[derive(Fail, Debug)]
 pub enum Error {
+    #[fail(display = "not found")]
+    NotFound,
+    #[fail(display = "integrity check failed")]
+    IntegrityError,
     #[fail(display = "{}", _0)]
     Io(#[fail(cause)] io::Error),
     #[fail(display = "{}", _0)]
diff --git a/src/get.rs b/src/get.rs
new file mode 100644
index 0000000..352498c
--- /dev/null
+++ b/src/get.rs
@@ -0,0 +1,39 @@
+use std::path::Path;
+
+use ssri::Integrity;
+
+use crate::content::read;
+use crate::errors::Error;
+use crate::index::{self, Entry};
+
+pub fn read(cache: &Path, key: String) -> Result<Vec<u8>, Error> {
+    if let Some(entry) = index::find(&cache, &key)? {
+        read_hash(cache, &entry.integrity)
+    } else {
+        Err(Error::NotFound)
+    }
+}
+
+pub fn read_hash(cache: &Path, sri: &Integrity) -> Result<Vec<u8>, Error> {
+    Ok(read::read(cache, sri)?)
+}
+
+pub fn copy(cache: &Path, key: String, to: &Path) -> Result<u64, Error> {
+    if let Some(entry) = index::find(&cache, &key)? {
+        copy_hash(cache, &entry.integrity, to)
+    } else {
+        Err(Error::NotFound)
+    }
+}
+
+pub fn copy_hash(cache: &Path, sri: &Integrity, to: &Path) -> Result<u64, Error> {
+    Ok(read::copy(cache, sri, to)?)
+}
+
+pub fn info(cache: &Path, key: String) -> Result<Option<Entry>, Error> {
+    index::find(cache, &key)
+}
+
+pub fn hash_exists(cache: &Path, sri: &Integrity) -> bool {
+    read::has_content(&cache, &sri).is_some()
+}
diff --git a/src/lib.rs b/src/lib.rs
index 6eeee60..2b13582 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,2 +1,7 @@
-pub mod content;
-pub mod index;
+mod content;
+pub mod get;
+mod index;
+mod errors;
+
+pub use errors::Error;
+pub use index::Entry;