diff --git a/crates/stellar-registry-cli/src/commands/create_alias.rs b/crates/stellar-registry-cli/src/commands/create_alias.rs
index e445328..3005e19 100644
--- a/crates/stellar-registry-cli/src/commands/create_alias.rs
+++ b/crates/stellar-registry-cli/src/commands/create_alias.rs
@@ -7,6 +7,7 @@ use stellar_strkey::Contract;
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of deployed contract. Can use prefix if not using verified registry.
     /// E.g. `unverified/<name>`
diff --git a/crates/stellar-registry-cli/src/commands/current_version.rs b/crates/stellar-registry-cli/src/commands/current_version.rs
index 653ccd8..091f4dc 100644
--- a/crates/stellar-registry-cli/src/commands/current_version.rs
+++ b/crates/stellar-registry-cli/src/commands/current_version.rs
@@ -5,6 +5,7 @@ use stellar_registry_build::name::{Prefixed, RegistryAccess};
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of published Wasm
     pub wasm_name: Prefixed,
diff --git a/crates/stellar-registry-cli/src/commands/download.rs b/crates/stellar-registry-cli/src/commands/download.rs
index c39549e..cbd82bd 100644
--- a/crates/stellar-registry-cli/src/commands/download.rs
+++ b/crates/stellar-registry-cli/src/commands/download.rs
@@ -7,6 +7,7 @@ use stellar_registry_build::name::{Prefixed, RegistryAccess};
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of published Wasm
     pub wasm_name: Prefixed,
diff --git a/crates/stellar-registry-cli/src/commands/fetch_account_id.rs b/crates/stellar-registry-cli/src/commands/fetch_account_id.rs
index 9e4dc01..38e1f69 100644
--- a/crates/stellar-registry-cli/src/commands/fetch_account_id.rs
+++ b/crates/stellar-registry-cli/src/commands/fetch_account_id.rs
@@ -5,6 +5,7 @@ use stellar_registry_build::name::{Prefixed, RegistryAccess};
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of the registered account. Can use prefix if not using verified registry.
     /// E.g. `unverified/<name>`
diff --git a/crates/stellar-registry-cli/src/commands/fetch_account_owner.rs b/crates/stellar-registry-cli/src/commands/fetch_account_owner.rs
index f6bcda3..4b1dbc9 100644
--- a/crates/stellar-registry-cli/src/commands/fetch_account_owner.rs
+++ b/crates/stellar-registry-cli/src/commands/fetch_account_owner.rs
@@ -5,6 +5,7 @@ use stellar_registry_build::name::{Prefixed, RegistryAccess};
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of the registered account. Can use prefix if not using verified registry.
     /// E.g. `unverified/<name>`
diff --git a/crates/stellar-registry-cli/src/commands/fetch_contract_id.rs b/crates/stellar-registry-cli/src/commands/fetch_contract_id.rs
index b3bd4d7..45d4112 100644
--- a/crates/stellar-registry-cli/src/commands/fetch_contract_id.rs
+++ b/crates/stellar-registry-cli/src/commands/fetch_contract_id.rs
@@ -6,6 +6,7 @@ use stellar_strkey::Contract;
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of deployed contract. Can use prefix if not using verified registry.
     /// E.g. `unverified/<name>`
diff --git a/crates/stellar-registry-cli/src/commands/fetch_hash.rs b/crates/stellar-registry-cli/src/commands/fetch_hash.rs
index b59aba4..f430d31 100644
--- a/crates/stellar-registry-cli/src/commands/fetch_hash.rs
+++ b/crates/stellar-registry-cli/src/commands/fetch_hash.rs
@@ -5,6 +5,7 @@ use stellar_registry_build::name::{Prefixed, RegistryAccess};
 use crate::commands::global;
 
 #[derive(Parser, Debug, Clone)]
+#[command(mut_arg("source_account", global::optional_source))]
 pub struct Cmd {
     /// Name of published Wasm
     pub wasm_name: Prefixed,
diff --git a/crates/stellar-registry-cli/src/commands/global.rs b/crates/stellar-registry-cli/src/commands/global.rs
index 5812d4b..b660a3d 100644
--- a/crates/stellar-registry-cli/src/commands/global.rs
+++ b/crates/stellar-registry-cli/src/commands/global.rs
@@ -22,3 +22,32 @@ impl Args {
         Ok(rpc::Client::new(&self.config.get_network()?.rpc_url)?)
     }
 }
+
+/// Simulation accepts any public key as the source, even an unfunded one.
+const READ_ONLY_SOURCE: &str = "GAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAWHF";
+
+/// For `#[command(mut_arg("source_account", global::optional_source))]` on
+/// commands that only simulate reads, so they run without an identity.
+pub fn optional_source(arg: clap::Arg) -> clap::Arg {
+    arg.required(false)
+        .default_value(READ_ONLY_SOURCE)
+        .hide_default_value(true)
+}
+
+#[cfg(test)]
+mod tests {
+    use clap::Parser;
+
+    #[derive(Parser)]
+    #[command(mut_arg("source_account", super::optional_source))]
+    struct Cmd {
+        #[command(flatten)]
+        config: super::Args,
+    }
+
+    #[test]
+    fn optional_source_needs_no_identity() {
+        let cmd = Cmd::try_parse_from(["cmd", "--network", "testnet"]).unwrap();
+        cmd.config.source_account().unwrap();
+    }
+}