diff --git a/Cargo.toml b/Cargo.toml
index f99db40..5ee4b67 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -23,7 +23,7 @@ license = "Apache-2.0"
 readme = "README.md"
 repository = "https://github.com/tisonkun/logforth"
 rust-version = "1.71.0"
-version = "0.6.0"
+version = "0.7.0"
 
 [package.metadata.docs.rs]
 all-features = true
@@ -44,18 +44,8 @@ rolling_file = ["dep:crossbeam-channel", "dep:parking_lot", "dep:time"]
 anyhow = { version = "1.0" }
 colored = { version = "2.1" }
 crossbeam-channel = { version = "0.5", optional = true }
-fastrace = { version = "0.6", optional = true }
 humantime = { version = "2.1" }
 log = { version = "0.4", features = ["std", "kv_unstable"] }
-opentelemetry = { version = "0.24", features = ["logs"], optional = true }
-opentelemetry-otlp = { version = "0.17", features = [
-  "logs",
-  "grpc-tonic",
-], optional = true }
-opentelemetry_sdk = { version = "0.24", features = [
-  "logs",
-  "rt-tokio",
-], optional = true }
 parking_lot = { version = "0.12", optional = true }
 paste = { version = "1.0" }
 serde = { version = "1.0", features = ["derive"], optional = true }
@@ -65,6 +55,28 @@ time = { version = "0.3", features = [
   "parsing",
 ], optional = true }
 
+## Fastrace dependencies
+[dependencies.fastrace]
+optional = true
+version = "0.6"
+
+## Opentelemetry dependencies
+[dependencies.opentelemetry]
+features = ["logs"]
+optional = true
+version = "0.24"
+
+[dependencies.opentelemetry-otlp]
+features = ["logs", "grpc-tonic", "http-json", "http-proto"]
+optional = true
+version = "0.17"
+
+[dependencies.opentelemetry_sdk]
+features = ["logs", "rt-tokio"]
+optional = true
+version = "0.24"
+
+## Examples
 [[example]]
 name = "fn_layout_filter"
 path = "examples/fn_layout_filter.rs"
diff --git a/README.md b/README.md
index 07df37a..0155e97 100644
--- a/README.md
+++ b/README.md
@@ -20,12 +20,15 @@ A versatile and extensible logging implementation.
 
 ## Usage
 
-Add the dependency to your `Cargo.toml` with:
+Add the dependencies to your `Cargo.toml` with:
 
 ```shell
+cargo add log
 cargo add logforth
 ```
 
+... where [log](https://crates.io/crates/log) is the logging facade and [logforth](https://crates.io/crates/logforth) is the logging implementation.
+
 Then, you can use the logger with:
 
 ```rust
diff --git a/src/append/opentelemetry.rs b/src/append/opentelemetry.rs
index 9a162a8..7c55da2 100644
--- a/src/append/opentelemetry.rs
+++ b/src/append/opentelemetry.rs
@@ -22,6 +22,7 @@ use opentelemetry::logs::Logger;
 use opentelemetry::logs::LoggerProvider as ILoggerProvider;
 use opentelemetry::logs::Severity;
 use opentelemetry::InstrumentationLibrary;
+use opentelemetry_otlp::Protocol;
 use opentelemetry_otlp::WithExportConfig;
 use opentelemetry_sdk::logs::LoggerProvider;
 
@@ -40,20 +41,38 @@ impl OpentelemetryLog {
         name: impl Into<String>,
         category: impl Into<String>,
         otlp_endpoint: impl Into<String>,
-    ) -> Self {
+        protocol: Protocol,
+    ) -> Result<Self, opentelemetry::logs::LogError> {
         let name = name.into();
         let category = category.into();
         let otlp_endpoint = otlp_endpoint.into();
 
-        let exporter = opentelemetry_otlp::new_exporter()
-            .tonic()
-            .with_endpoint(otlp_endpoint)
-            .with_protocol(opentelemetry_otlp::Protocol::Grpc)
-            .with_timeout(Duration::from_secs(
-                opentelemetry_otlp::OTEL_EXPORTER_OTLP_TIMEOUT_DEFAULT,
-            ))
-            .build_log_exporter()
-            .expect("failed to initialize oltp exporter");
+        let exporter = match protocol {
+            Protocol::Grpc => opentelemetry_otlp::new_exporter()
+                .tonic()
+                .with_endpoint(otlp_endpoint)
+                .with_protocol(Protocol::Grpc)
+                .with_timeout(Duration::from_secs(
+                    opentelemetry_otlp::OTEL_EXPORTER_OTLP_TIMEOUT_DEFAULT,
+                ))
+                .build_log_exporter(),
+            Protocol::HttpBinary => opentelemetry_otlp::new_exporter()
+                .http()
+                .with_endpoint(otlp_endpoint)
+                .with_protocol(Protocol::HttpBinary)
+                .with_timeout(Duration::from_secs(
+                    opentelemetry_otlp::OTEL_EXPORTER_OTLP_TIMEOUT_DEFAULT,
+                ))
+                .build_log_exporter(),
+            Protocol::HttpJson => opentelemetry_otlp::new_exporter()
+                .http()
+                .with_endpoint(otlp_endpoint)
+                .with_protocol(Protocol::HttpJson)
+                .with_timeout(Duration::from_secs(
+                    opentelemetry_otlp::OTEL_EXPORTER_OTLP_TIMEOUT_DEFAULT,
+                ))
+                .build_log_exporter(),
+        }?;
 
         let provider = LoggerProvider::builder()
             .with_batch_exporter(exporter, opentelemetry_sdk::runtime::Tokio)
@@ -61,12 +80,12 @@ impl OpentelemetryLog {
 
         let library = Arc::new(InstrumentationLibrary::builder(name.clone()).build());
 
-        Self {
+        Ok(Self {
             name,
             category,
             library,
             provider,
-        }
+        })
     }
 }
 
diff --git a/src/layout/json.rs b/src/layout/json.rs
index 30d716b..3298965 100644
--- a/src/layout/json.rs
+++ b/src/layout/json.rs
@@ -84,7 +84,7 @@ impl JsonLayout {
             level: record.level().as_str(),
             module_path: record.module_path().unwrap_or_default(),
             file: record.file().unwrap_or_default(),
-            line: record.line().unwrap_or(0),
+            line: record.line().unwrap_or_default(),
             message: record.args(),
             kvs,
         };
diff --git a/src/layout/text.rs b/src/layout/text.rs
index 5fcc57a..6de907d 100644
--- a/src/layout/text.rs
+++ b/src/layout/text.rs
@@ -66,7 +66,7 @@ impl TextLayout {
         let level = ColoredString::from(record.level().to_string()).color(color);
         let module = record.module_path().unwrap_or_default();
         let file = record.file().unwrap_or_default();
-        let line = record.line().unwrap_or(0);
+        let line = record.line().unwrap_or_default();
         let message = record.args();
         let kvs = KvDisplay::new(record.key_values());