From 8820547a0716fcda4f72e24f49837f8dc7ee8e51 Mon Sep 17 00:00:00 2001
From: Vincent Koc <vincentkoc@ieee.org>
Date: Mon, 13 Apr 2026 16:12:09 +0100
Subject: [PATCH] perf(config): reuse validated best-effort snapshots

---
 src/config/io.best-effort.test.ts | 35 +++++++++++
 src/config/io.ts                  | 99 +++++++++++++++++--------------
 2 files changed, 91 insertions(+), 43 deletions(-)
 create mode 100644 src/config/io.best-effort.test.ts

diff --git a/src/config/io.best-effort.test.ts b/src/config/io.best-effort.test.ts
new file mode 100644
index 00000000000..accd9440c16
--- /dev/null
+++ b/src/config/io.best-effort.test.ts
@@ -0,0 +1,35 @@
+import { describe, expect, it } from "vitest";
+import { readBestEffortConfig, readConfigFileSnapshot } from "./config.js";
+import { withTempHome, writeOpenClawConfig } from "./test-helpers.js";
+
+describe("readBestEffortConfig", () => {
+  it("reuses valid snapshots while preserving load-time defaults", async () => {
+    await withTempHome(async (home) => {
+      await writeOpenClawConfig(home, {
+        auth: {
+          profiles: {
+            "anthropic:api": { provider: "anthropic", mode: "api_key" },
+          },
+        },
+        agents: {
+          defaults: {
+            model: { primary: "anthropic/claude-opus-4-6" },
+          },
+        },
+      });
+
+      const snapshot = await readConfigFileSnapshot();
+      const bestEffort = await readBestEffortConfig();
+
+      expect(snapshot.config.agents?.defaults?.contextPruning?.mode).toBeUndefined();
+      expect(snapshot.config.agents?.defaults?.compaction?.mode).toBeUndefined();
+
+      expect(bestEffort.agents?.defaults?.contextPruning?.mode).toBe("cache-ttl");
+      expect(bestEffort.agents?.defaults?.contextPruning?.ttl).toBe("1h");
+      expect(bestEffort.agents?.defaults?.compaction?.mode).toBe("safeguard");
+      expect(
+        bestEffort.agents?.defaults?.models?.["anthropic/claude-opus-4-6"]?.params?.cacheRetention,
+      ).toBe("short");
+    });
+  });
+});
diff --git a/src/config/io.ts b/src/config/io.ts
index 165a6b33d93..8690ed7ba6d 100644
--- a/src/config/io.ts
+++ b/src/config/io.ts
@@ -1030,6 +1030,49 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
     return snapshot;
   }
 
+  function finalizeLoadedRuntimeConfig(cfg: OpenClawConfig): OpenClawConfig {
+    const duplicates = findDuplicateAgentDirs(cfg, {
+      env: deps.env,
+      homedir: deps.homedir,
+    });
+    if (duplicates.length > 0) {
+      throw new DuplicateAgentDirError(duplicates);
+    }
+
+    applyConfigEnvVars(cfg, deps.env);
+
+    const enabled = shouldEnableShellEnvFallback(deps.env) || cfg.env?.shellEnv?.enabled === true;
+    if (enabled && !shouldDeferShellEnvFallback(deps.env)) {
+      loadShellEnvFallback({
+        enabled: true,
+        env: deps.env,
+        expectedKeys: resolveShellEnvExpectedKeys(deps.env),
+        logger: deps.logger,
+        timeoutMs: cfg.env?.shellEnv?.timeoutMs ?? resolveShellEnvFallbackTimeoutMs(deps.env),
+      });
+    }
+
+    const pendingSecret = AUTO_OWNER_DISPLAY_SECRET_BY_PATH.get(configPath);
+    const ownerDisplaySecretResolution = ensureOwnerDisplaySecret(
+      cfg,
+      () => pendingSecret ?? crypto.randomBytes(32).toString("hex"),
+    );
+    const cfgWithOwnerDisplaySecret = persistGeneratedOwnerDisplaySecret({
+      config: ownerDisplaySecretResolution.config,
+      configPath,
+      generatedSecret: ownerDisplaySecretResolution.generatedSecret,
+      logger: deps.logger,
+      state: {
+        pendingByPath: AUTO_OWNER_DISPLAY_SECRET_BY_PATH,
+        persistInFlight: AUTO_OWNER_DISPLAY_SECRET_PERSIST_IN_FLIGHT,
+        persistWarned: AUTO_OWNER_DISPLAY_SECRET_PERSIST_WARNED,
+      },
+      persistConfig: (nextConfig, options) => writeConfigFile(nextConfig, options),
+    });
+
+    return applyConfigOverrides(cfgWithOwnerDisplaySecret);
+  }
+
   function loadConfig(): OpenClawConfig {
     try {
       maybeLoadDotEnvForConfig(deps.env);
@@ -1144,47 +1187,7 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
           legacyIssues: legacyResolution.sourceLegacyIssues,
         }),
       });
-
-      const duplicates = findDuplicateAgentDirs(cfg, {
-        env: deps.env,
-        homedir: deps.homedir,
-      });
-      if (duplicates.length > 0) {
-        throw new DuplicateAgentDirError(duplicates);
-      }
-
-      applyConfigEnvVars(cfg, deps.env);
-
-      const enabled = shouldEnableShellEnvFallback(deps.env) || cfg.env?.shellEnv?.enabled === true;
-      if (enabled && !shouldDeferShellEnvFallback(deps.env)) {
-        loadShellEnvFallback({
-          enabled: true,
-          env: deps.env,
-          expectedKeys: resolveShellEnvExpectedKeys(deps.env),
-          logger: deps.logger,
-          timeoutMs: cfg.env?.shellEnv?.timeoutMs ?? resolveShellEnvFallbackTimeoutMs(deps.env),
-        });
-      }
-
-      const pendingSecret = AUTO_OWNER_DISPLAY_SECRET_BY_PATH.get(configPath);
-      const ownerDisplaySecretResolution = ensureOwnerDisplaySecret(
-        cfg,
-        () => pendingSecret ?? crypto.randomBytes(32).toString("hex"),
-      );
-      const cfgWithOwnerDisplaySecret = persistGeneratedOwnerDisplaySecret({
-        config: ownerDisplaySecretResolution.config,
-        configPath,
-        generatedSecret: ownerDisplaySecretResolution.generatedSecret,
-        logger: deps.logger,
-        state: {
-          pendingByPath: AUTO_OWNER_DISPLAY_SECRET_BY_PATH,
-          persistInFlight: AUTO_OWNER_DISPLAY_SECRET_PERSIST_IN_FLIGHT,
-          persistWarned: AUTO_OWNER_DISPLAY_SECRET_PERSIST_WARNED,
-        },
-        persistConfig: (nextConfig, options) => writeConfigFile(nextConfig, options),
-      });
-
-      return applyConfigOverrides(cfgWithOwnerDisplaySecret);
+      return finalizeLoadedRuntimeConfig(cfg);
     } catch (err) {
       if (err instanceof DuplicateAgentDirError) {
         deps.logger.error(err.message);
@@ -1389,6 +1392,16 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
     };
   }
 
+  async function readBestEffortConfig(): Promise<OpenClawConfig> {
+    const result = await readConfigFileSnapshotInternal();
+    if (!result.snapshot.valid) {
+      return result.snapshot.config;
+    }
+    return finalizeLoadedRuntimeConfig(
+      materializeRuntimeConfig(result.snapshot.sourceConfig, "load"),
+    );
+  }
+
   async function writeConfigFile(
     cfg: OpenClawConfig,
     options: ConfigWriteOptions = {},
@@ -1649,6 +1662,7 @@ export function createConfigIO(overrides: ConfigIoDeps = {}) {
   return {
     configPath,
     loadConfig,
+    readBestEffortConfig,
     readConfigFileSnapshot,
     readConfigFileSnapshotForWrite,
     writeConfigFile,
@@ -1740,8 +1754,7 @@ export function getRuntimeConfig(): OpenClawConfig {
 }
 
 export async function readBestEffortConfig(): Promise<OpenClawConfig> {
-  const snapshot = await readConfigFileSnapshot();
-  return snapshot.valid ? loadConfig() : snapshot.config;
+  return await createConfigIO().readBestEffortConfig();
 }
 
 export async function readConfigFileSnapshot(): Promise<ConfigFileSnapshot> {