diff --git a/buzz-agent-core/Cargo.toml b/buzz-agent-core/Cargo.toml
index 8e32304b42..5c348783c8 100644
--- a/buzz-agent-core/Cargo.toml
+++ b/buzz-agent-core/Cargo.toml
@@ -31,8 +31,15 @@ publish = false
 name = "buzz_agent_core"
 path = "src/lib.rs"
 
+# Emitted as `buzz-agent`, not `buzz-agent-core`, on purpose. buzz-acp derives
+# a harness identity from the command's BASENAME
+# (`normalize_agent_command_identity`, buzz-acp/src/config.rs:600-615) and
+# already has a `"buzz-agent"` arm meaning "no extra args"
+# (`default_agent_args`, :617-624). Naming the binary this way makes it a
+# drop-in swap: point BUZZ_ACP_AGENT_COMMAND at it and buzz-acp cannot tell the
+# difference.
 [[bin]]
-name = "buzz-agent-core"
+name = "buzz-agent"
 path = "src/main.rs"
 
 # Test-only fake MCP server, copied from crates/buzz-agent. Built
diff --git a/buzz-agent-core/tests/cancel.rs b/buzz-agent-core/tests/cancel.rs
index a811f6af9d..601db76e9c 100644
--- a/buzz-agent-core/tests/cancel.rs
+++ b/buzz-agent-core/tests/cancel.rs
@@ -119,7 +119,7 @@ struct Harness {
 
 impl Harness {
     fn start(base_url: &str, home: &std::path::Path) -> Self {
-        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent-core"))
+        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent"))
             .env("BUZZ_AGENT_PROVIDER", "openai-compat")
             .env("BUZZ_AGENT_MODEL", "fake-model")
             .env("OPENAI_COMPAT_API_KEY", "k")
diff --git a/buzz-agent-core/tests/real_dev_mcp.rs b/buzz-agent-core/tests/real_dev_mcp.rs
index 734145b847..4f9d90f0ef 100644
--- a/buzz-agent-core/tests/real_dev_mcp.rs
+++ b/buzz-agent-core/tests/real_dev_mcp.rs
@@ -169,7 +169,7 @@ struct Harness {
 
 impl Harness {
     fn start(base_url: &str, home: &std::path::Path) -> Self {
-        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent-core"))
+        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent"))
             .env("BUZZ_AGENT_PROVIDER", "openai-compat")
             .env("BUZZ_AGENT_MODEL", "fake-model")
             .env("OPENAI_COMPAT_API_KEY", "k")
diff --git a/buzz-agent-core/tests/reflect.rs b/buzz-agent-core/tests/reflect.rs
index 0ddb40e779..b64308cedf 100644
--- a/buzz-agent-core/tests/reflect.rs
+++ b/buzz-agent-core/tests/reflect.rs
@@ -146,7 +146,7 @@ struct Harness {
 
 impl Harness {
     fn start(base_url: &str, home: &std::path::Path) -> Self {
-        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent-core"))
+        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent"))
             .env("BUZZ_AGENT_PROVIDER", "openai-compat")
             .env("BUZZ_AGENT_MODEL", "fake-model")
             .env("OPENAI_COMPAT_API_KEY", "k")
diff --git a/buzz-agent-core/tests/stdio_turn.rs b/buzz-agent-core/tests/stdio_turn.rs
index c2a46860ba..4f3983c449 100644
--- a/buzz-agent-core/tests/stdio_turn.rs
+++ b/buzz-agent-core/tests/stdio_turn.rs
@@ -154,7 +154,7 @@ struct Harness {
 
 impl Harness {
     fn start(base_url: &str, home: &std::path::Path) -> Self {
-        let exe = env!("CARGO_BIN_EXE_buzz-agent-core");
+        let exe = env!("CARGO_BIN_EXE_buzz-agent");
         let mut child = Command::new(exe)
             // Buzz-shaped config; config.rs translates these onto GOOSE_*.
             .env("BUZZ_AGENT_PROVIDER", "openai-compat")
diff --git a/buzz-agent-core/tests/steer.rs b/buzz-agent-core/tests/steer.rs
index 335bf10de8..6328f0afd4 100644
--- a/buzz-agent-core/tests/steer.rs
+++ b/buzz-agent-core/tests/steer.rs
@@ -151,7 +151,7 @@ struct Harness {
 
 impl Harness {
     fn start(base_url: &str, home: &std::path::Path) -> Self {
-        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent-core"))
+        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent"))
             .env("BUZZ_AGENT_PROVIDER", "openai-compat")
             .env("BUZZ_AGENT_MODEL", "fake-model")
             .env("OPENAI_COMPAT_API_KEY", "k")
diff --git a/buzz-agent-core/tests/stop_hook.rs b/buzz-agent-core/tests/stop_hook.rs
index 42b56b7d9f..cdfdf061fd 100644
--- a/buzz-agent-core/tests/stop_hook.rs
+++ b/buzz-agent-core/tests/stop_hook.rs
@@ -116,7 +116,7 @@ struct Harness {
 
 impl Harness {
     fn start(base_url: &str, home: &std::path::Path) -> Self {
-        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent-core"))
+        let mut child = Command::new(env!("CARGO_BIN_EXE_buzz-agent"))
             .env("BUZZ_AGENT_PROVIDER", "openai-compat")
             .env("BUZZ_AGENT_MODEL", "fake-model")
             .env("OPENAI_COMPAT_API_KEY", "k")