diff --git a/cmd/artex/main.go b/cmd/artex/main.go
index 0ce0b02..46c5ab3 100644
--- a/cmd/artex/main.go
+++ b/cmd/artex/main.go
@@ -94,6 +94,7 @@ func run() int {
 	}
 	log.Printf("[config] skill directory: %s", skillDir)
 	srv := server.New(ctx, mgr, skillDir, *dataDir, config.BaseDir())
+	scrubSecretEnv()
 	httpSrv := &http.Server{
 		Addr:              *addr,
 		Handler:           srv.Handler(),
@@ -117,6 +118,19 @@ func run() int {
 	return 0
 }
 
+// secretEnv lists the credentials read from the environment only at startup:
+// ARTEX_PG_DSN by server.NewManager, the API keys by agent.FromEnv in server.New.
+var secretEnv = []string{"ARTEX_PG_DSN", "ANTHROPIC_API_KEY", "OPENAI_API_KEY"}
+
+// scrubSecretEnv removes secretEnv from the process environment once startup has
+// read it. Child processes (agent shells, custom tools, MCP stdio servers) copy
+// os.Environ() when they are spawned, so they no longer inherit these values.
+func scrubSecretEnv() {
+	for _, k := range secretEnv {
+		_ = os.Unsetenv(k)
+	}
+}
+
 // shutdownContext deliberately does not derive from signalCtx. If it did, the
 // parent's plain context.Canceled could win the race before AbortShutdown was
 // attached to the child, losing the diagnostic cause in every running Agent.
diff --git a/cmd/artex/main_test.go b/cmd/artex/main_test.go
index 149c7c6..b89e44d 100644
--- a/cmd/artex/main_test.go
+++ b/cmd/artex/main_test.go
@@ -2,11 +2,42 @@ package main
 
 import (
 	"context"
+	"os/exec"
+	"strings"
 	"testing"
 
 	"github.com/Autumn-27/artex/agent"
 )
 
+// A child process spawned after startup must not see the startup secrets, while
+// other variables still pass through.
+func TestScrubSecretEnvHidesSecretsFromChildren(t *testing.T) {
+	sh, err := exec.LookPath("sh")
+	if err != nil {
+		t.Skip("no sh in PATH")
+	}
+	for _, k := range secretEnv {
+		t.Setenv(k, "leak-"+k)
+	}
+	t.Setenv("ARTEX_SCRUB_KEEP", "kept")
+
+	scrubSecretEnv()
+
+	out, err := exec.Command(sh, "-c", "env").Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+	env := "\n" + string(out)
+	for _, k := range secretEnv {
+		if strings.Contains(env, "\n"+k+"=") {
+			t.Errorf("%s still reaches child processes", k)
+		}
+	}
+	if !strings.Contains(env, "\nARTEX_SCRUB_KEEP=kept\n") {
+		t.Errorf("non-secret variable did not reach the child process")
+	}
+}
+
 func TestShutdownContextPreservesNamedCause(t *testing.T) {
 	signalCtx, signalCancel := context.WithCancel(context.Background())
 	ctx, shutdown := shutdownContext(signalCtx)