diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
index 8ae4cfc..8f5336f 100644
--- a/ARCHITECTURE.md
+++ b/ARCHITECTURE.md
@@ -10,6 +10,14 @@ The entry point for the library is `src/lib.rs` as per usual.
 In these files no particular implementation of a policy reasoner is included, only
 the mechanisms on which the concept of a policy reasoner can be implemented.
 
+### Interface
+
+The interface for the different reasoners must be the same. Its command line
+arguments are defined in `src/bin/implementation/interface.rs`. It could be that a new
+reasoner requires more arguments. You can implement another arguments struct, however
+make sure the arguments defined in the common interface are supported as other
+components of infrastructure may depend on it.
+
 ### Implementations
 
 As of now there are three different implementations of a policy reasoners in
diff --git a/src/bin/eflint.rs b/src/bin/eflint.rs
index 8d10765..e4d4e2c 100644
--- a/src/bin/eflint.rs
+++ b/src/bin/eflint.rs
@@ -16,7 +16,6 @@ pub mod implementation;
 
 use std::env;
 use std::fs::File;
-use std::net::SocketAddr;
 
 use clap::Parser;
 use error_trace::ErrorTrace as _;
@@ -26,6 +25,7 @@ use implementation::eflint::EFlintLeakNoErrors;
 #[cfg(feature = "leak-public-errors")]
 use implementation::eflint::EFlintLeakPrefixErrors;
 use implementation::eflint::EFlintReasonerConnector;
+use implementation::interface::Arguments;
 use log::{error, info};
 use policy_reasoner::auth::{JwtConfig, JwtResolver, KidResolver};
 use policy_reasoner::logger::FileLogger;
@@ -46,43 +46,6 @@ fn get_dauth_resolver() -> JwtResolver<KidResolver> {
     JwtResolver::new(jwt_cfg, kid_resolver).unwrap()
 }
 
-/***** ARGUMENTS *****/
-/// Defines the arguments for the `policy-reasoner` server.
-#[derive(Debug, Parser)]
-struct Arguments {
-    /// Whether to enable full debugging
-    #[clap(long, global = true, help = "If given, enables more verbose debugging.")]
-    trace: bool,
-
-    /// The address on which to bind ourselves.
-    #[clap(short, long, env, default_value = "127.0.0.1:3030", help = "The address on which to bind the server.")]
-    address: SocketAddr,
-
-    /// Shows the help menu for the state resolver.
-    #[clap(long, help = "If given, shows the possible arguments to pass to the state resolver plugin in '--state-resolver'.")]
-    help_state_resolver: bool,
-    /// Arguments specific to the state resolver.
-    #[clap(
-        short,
-        long,
-        env,
-        help = "Arguments to pass to the current state resolver plugin. To find which are possible, see '--help-state-resolver'."
-    )]
-    state_resolver:      Option<String>,
-
-    /// Shows the help menu for the reasoner connector.
-    #[clap(long, help = "If given, shows the possible arguments to pass to the reasoner connector plugin in '--reasoner-connector'.")]
-    help_reasoner_connector: bool,
-    /// Arguments specific to the state resolver.
-    #[clap(
-        short,
-        long,
-        env,
-        help = "Arguments to pass to the current reasoner connector plugin. To find which are possible, see '--help-reasoner-connector'."
-    )]
-    reasoner_connector:      Option<String>,
-}
-
 /***** PLUGINS *****/
 /// The plugin used to do the audit logging.
 type AuditLogPlugin = FileLogger;
diff --git a/src/bin/implementation/interface.rs b/src/bin/implementation/interface.rs
new file mode 100644
index 0000000..00a988f
--- /dev/null
+++ b/src/bin/implementation/interface.rs
@@ -0,0 +1,42 @@
+use std::net::SocketAddr;
+
+use clap::Parser;
+
+/***** ARGUMENTS *****/
+/// Defines the arguments for the `policy-reasoner` server.
+#[derive(Debug, Parser)]
+pub struct Arguments {
+    /// Whether to enable full debugging
+    #[clap(long, global = true, help = "If given, enables more verbose debugging.")]
+    pub trace: bool,
+
+    /// The address on which to bind ourselves.
+    #[clap(short, long, env, default_value = "127.0.0.1:3030", help = "The address on which to bind the server.")]
+    pub address: SocketAddr,
+
+    /// Shows the help menu for the state resolver.
+    #[clap(long, help = "If given, shows the possible arguments to pass to the state resolver plugin in '--state-resolver'.")]
+    pub help_state_resolver: bool,
+
+    /// Arguments specific to the state resolver.
+    #[clap(
+        short,
+        long,
+        env,
+        help = "Arguments to pass to the current state resolver plugin. To find which are possible, see '--help-state-resolver'."
+    )]
+    pub state_resolver: Option<String>,
+
+    /// Shows the help menu for the reasoner connector.
+    #[clap(long, help = "If given, shows the possible arguments to pass to the reasoner connector plugin in '--reasoner-connector'.")]
+    pub help_reasoner_connector: bool,
+
+    /// Arguments specific to the state resolver.
+    #[clap(
+        short,
+        long,
+        env,
+        help = "Arguments to pass to the current reasoner connector plugin. To find which are possible, see '--help-reasoner-connector'."
+    )]
+    pub reasoner_connector: Option<String>,
+}
diff --git a/src/bin/implementation/mod.rs b/src/bin/implementation/mod.rs
index cc12764..e7bc293 100644
--- a/src/bin/implementation/mod.rs
+++ b/src/bin/implementation/mod.rs
@@ -1,3 +1,4 @@
 pub mod eflint;
+pub mod interface;
 pub mod no_op;
 pub mod posix;
diff --git a/src/bin/no_op.rs b/src/bin/no_op.rs
index 8533177..7c6c7d3 100644
--- a/src/bin/no_op.rs
+++ b/src/bin/no_op.rs
@@ -3,13 +3,13 @@
 //! policy reasoner.
 use std::env;
 use std::fs::File;
-use std::net::SocketAddr;
 
 pub mod implementation;
 
 use clap::Parser;
 use error_trace::ErrorTrace as _;
 use humanlog::{DebugMode, HumanLogger};
+use implementation::interface::Arguments;
 use implementation::no_op::NoOpReasonerConnector;
 use log::{error, info};
 use policy_reasoner::auth::{JwtConfig, JwtResolver, KidResolver};
@@ -33,19 +33,6 @@ fn get_dauth_resolver() -> policy_reasoner::auth::JwtResolver<KidResolver> {
     JwtResolver::new(jwt_cfg, kid_resolver).unwrap()
 }
 
-/***** ARGUMENTS *****/
-/// Defines the arguments for the `policy-reasoner` server.
-#[derive(Debug, Parser, Clone)]
-struct Arguments {
-    /// Whether to enable full debugging
-    #[clap(long, global = true, help = "If given, enables more verbose debugging.")]
-    trace: bool,
-
-    /// The address on which to bind ourselves.
-    #[clap(short, long, env, default_value = "127.0.0.1:3030", help = "The address on which to bind the server.")]
-    address: SocketAddr,
-}
-
 /***** PLUGINS *****/
 /// The plugin used to do the audit logging.
 type AuditLogPlugin = FileLogger;
diff --git a/src/bin/posix.rs b/src/bin/posix.rs
index 093f163..dbf280a 100644
--- a/src/bin/posix.rs
+++ b/src/bin/posix.rs
@@ -16,11 +16,11 @@ pub mod implementation;
 
 use std::env;
 use std::fs::File;
-use std::net::SocketAddr;
 
 use clap::Parser;
 use error_trace::ErrorTrace as _;
 use humanlog::{DebugMode, HumanLogger};
+use implementation::interface::Arguments;
 use implementation::posix;
 use log::{error, info};
 use policy_reasoner::auth::{JwtConfig, JwtResolver, KidResolver};
@@ -44,43 +44,6 @@ fn get_dauth_resolver() -> policy_reasoner::auth::JwtResolver<KidResolver> {
     JwtResolver::new(jwt_cfg, kid_resolver).unwrap()
 }
 
-/***** ARGUMENTS *****/
-/// Defines the arguments for the `policy-reasoner` server.
-#[derive(Debug, Parser, Clone)]
-struct Arguments {
-    /// Whether to enable full debugging
-    #[clap(long, global = true, help = "If given, enables more verbose debugging.")]
-    trace: bool,
-
-    /// The address on which to bind ourselves.
-    #[clap(short, long, env, default_value = "127.0.0.1:3030", help = "The address on which to bind the server.")]
-    address: SocketAddr,
-
-    /// Shows the help menu for the state resolver.
-    #[clap(long, help = "If given, shows the possible arguments to pass to the state resolver plugin in '--state-resolver'.")]
-    help_state_resolver: bool,
-    /// Arguments specific to the state resolver.
-    #[clap(
-        short,
-        long,
-        env,
-        help = "Arguments to pass to the current state resolver plugin. To find which are possible, see '--help-state-resolver'."
-    )]
-    state_resolver:      Option<String>,
-
-    /// Shows the help menu for the reasoner connector.
-    #[clap(long, help = "If given, shows the possible arguments to pass to the reasoner connector plugin in '--reasoner-connector'.")]
-    help_reasoner_connector: bool,
-    /// Arguments specific to the state resolver.
-    #[clap(
-        short,
-        long,
-        env,
-        help = "Arguments to pass to the current reasoner connector plugin. To find which are possible, see '--help-reasoner-connector'."
-    )]
-    reasoner_connector:      Option<String>,
-}
-
 /***** PLUGINS *****/
 /// The plugin used to do the audit logging.
 type AuditLogPlugin = FileLogger;