diff --git a/extensions/openrouter/index.test.ts b/extensions/openrouter/index.test.ts
index eb93f922a539..78048ec7ae5f 100644
--- a/extensions/openrouter/index.test.ts
+++ b/extensions/openrouter/index.test.ts
@@ -597,6 +597,30 @@ describe("openrouter provider hooks", () => {
     expect(contribution?.dynamicSuffix).not.toContain("google/gemini-3.5-flash");
   });
 
+  it("omits Fusion prompt details when a narrower scope disables extra body", async () => {
+    const provider = await registerSingleProviderPlugin(openrouterPlugin);
+    const contribution = provider.resolveSystemPromptContribution?.({
+      provider: "openrouter",
+      modelId: "openrouter/fusion",
+      promptMode: "full",
+      agentId: "analyst",
+      config: {
+        agents: {
+          defaults: {
+            params: {
+              extra_body: {
+                plugins: [{ id: "fusion", analysis_models: ["default/model"] }],
+              },
+            },
+          },
+          entries: { analyst: { params: { extraBody: null } } },
+        },
+      },
+    } as never);
+
+    expect(contribution).toBeUndefined();
+  });
+
   it("reads per-agent Fusion config from the canonical agent roster", async () => {
     const provider = await registerSingleProviderPlugin(openrouterPlugin);
     const contribution = provider.resolveSystemPromptContribution?.({
diff --git a/extensions/openrouter/index.ts b/extensions/openrouter/index.ts
index 84c5aa168002..7672584a4725 100644
--- a/extensions/openrouter/index.ts
+++ b/extensions/openrouter/index.ts
@@ -162,12 +162,11 @@ function resolveFusionExtraBody(
   ];
   let effective: Record<string, unknown> | undefined;
   for (const source of sources) {
-    const raw =
-      source && Object.hasOwn(source, "extra_body") ? source.extra_body : source?.extraBody;
-    const candidate = readRecord(raw);
-    if (candidate) {
-      effective = candidate;
+    if (!source || (!Object.hasOwn(source, "extra_body") && !Object.hasOwn(source, "extraBody"))) {
+      continue;
     }
+    const raw = Object.hasOwn(source, "extra_body") ? source.extra_body : source.extraBody;
+    effective = readRecord(raw);
   }
   return effective;
 }
diff --git a/src/agents/command/model-selection.ts b/src/agents/command/model-selection.ts
index 432dfae2f03a..2e8702989e9c 100644
--- a/src/agents/command/model-selection.ts
+++ b/src/agents/command/model-selection.ts
@@ -514,6 +514,7 @@ export async function resolveEmbeddedModelSelection(params: {
       cfg: params.cfg,
       provider,
       model,
+      agentId: params.sessionAgentId,
     });
   let catalogForThinking =
     allowedModelCatalog.length > 0
diff --git a/src/agents/command/run-embedded-attempt.ts b/src/agents/command/run-embedded-attempt.ts
index 585e014cd894..3355923f144a 100644
--- a/src/agents/command/run-embedded-attempt.ts
+++ b/src/agents/command/run-embedded-attempt.ts
@@ -386,6 +386,7 @@ export async function runEmbeddedAgentAttempt(params: {
               cfg,
               provider: providerOverride,
               model: modelOverride,
+              agentId: sessionAgentId,
             });
           let candidateThinkingCatalog = thinkingCatalog;
           if (
diff --git a/src/agents/embedded-agent-runner/run/runtime-preparation.ts b/src/agents/embedded-agent-runner/run/runtime-preparation.ts
index 7a61bdf065fe..cf2b51b48b34 100644
--- a/src/agents/embedded-agent-runner/run/runtime-preparation.ts
+++ b/src/agents/embedded-agent-runner/run/runtime-preparation.ts
@@ -220,6 +220,7 @@ export async function prepareEmbeddedRunRuntime(input: {
     provider,
     modelId,
     model: effectiveModel,
+    agentId: params.agentId,
   });
   const initialThinkLevel = modelSelectionChangedByHook
     ? (resolveCandidateThinkingLevel({
diff --git a/src/agents/embedded-agent-runner/run/runtime-resolution.test.ts b/src/agents/embedded-agent-runner/run/runtime-resolution.test.ts
index 6c30078d9a9b..13992bca51b7 100644
--- a/src/agents/embedded-agent-runner/run/runtime-resolution.test.ts
+++ b/src/agents/embedded-agent-runner/run/runtime-resolution.test.ts
@@ -26,4 +26,27 @@ describe("resolveInitialThinkLevel", () => {
       }),
     ).toBe("ultra");
   });
+
+  it("uses the selected agent model thinking default", () => {
+    expect(
+      resolveInitialThinkLevel({
+        config: {
+          agents: {
+            defaults: {
+              models: { "openai/gpt-5.5": { params: { thinking: "low" } } },
+            },
+            entries: {
+              audit: {
+                models: { "openai/gpt-5.5": { params: { thinking: "high" } } },
+              },
+            },
+          },
+        },
+        provider: "openai",
+        modelId: "gpt-5.5",
+        model: { reasoning: true },
+        agentId: "audit",
+      }),
+    ).toBe("high");
+  });
 });
diff --git a/src/agents/embedded-agent-runner/run/runtime-resolution.ts b/src/agents/embedded-agent-runner/run/runtime-resolution.ts
index b78472174ce2..3285e6c08abf 100644
--- a/src/agents/embedded-agent-runner/run/runtime-resolution.ts
+++ b/src/agents/embedded-agent-runner/run/runtime-resolution.ts
@@ -57,6 +57,7 @@ export function resolveInitialThinkLevel(params: {
   provider: string;
   modelId: string;
   model: { reasoning?: boolean };
+  agentId?: string;
 }): ThinkLevel {
   if (params.requested) {
     return params.requested;
@@ -65,6 +66,7 @@ export function resolveInitialThinkLevel(params: {
     cfg: params.config ?? {},
     provider: params.provider,
     model: params.modelId,
+    agentId: params.agentId,
     catalog: [
       {
         provider: params.provider,
diff --git a/src/agents/model-thinking-default-core.ts b/src/agents/model-thinking-default-core.ts
index 36b0da36e709..b457f66fe237 100644
--- a/src/agents/model-thinking-default-core.ts
+++ b/src/agents/model-thinking-default-core.ts
@@ -14,6 +14,7 @@ import {
 } from "../auto-reply/thinking.shared.js";
 import type { OpenClawConfig } from "../config/types.openclaw.js";
 import type { ModelCatalogEntry } from "./model-catalog.types.js";
+import { resolveModelExtraParamSources } from "./model-extra-params.js";
 import { legacyModelKey, modelKey, normalizeProviderId } from "./model-ref-shared.js";
 import { normalizeModelSelection } from "./model-selection-resolve.js";
 import { buildConfiguredModelCatalog } from "./model-selection-shared.js";
@@ -24,19 +25,25 @@ type ThinkingDefaultParams = {
   model: string;
   catalog?: ModelCatalogEntry[];
   agentRuntime?: string | null;
+  agentId?: string;
 };
 
 export function resolveConfiguredThinkingDefaultCore(params: {
   cfg: OpenClawConfig;
   provider: string;
   model: string;
+  agentId?: string;
 }): ThinkLevel | undefined {
-  const configuredModels = params.cfg.agents?.defaults?.models;
-  const canonicalKey = modelKey(params.provider, params.model);
-  const legacyKey = legacyModelKey(params.provider, params.model);
+  const { modelParams, agentModelParams } = resolveModelExtraParamSources({
+    config: params.cfg,
+    provider: params.provider,
+    modelId: params.model,
+    agentId: params.agentId,
+  });
   const perModelThinking =
-    configuredModels?.[canonicalKey]?.params?.thinking ??
-    (legacyKey ? configuredModels?.[legacyKey]?.params?.thinking : undefined);
+    agentModelParams && Object.hasOwn(agentModelParams, "thinking")
+      ? agentModelParams.thinking
+      : modelParams?.thinking;
   if (
     perModelThinking === false ||
     perModelThinking === "disabled" ||
diff --git a/src/agents/model-thinking-default.ts b/src/agents/model-thinking-default.ts
index 6f243f2a97c2..caddbd32c259 100644
--- a/src/agents/model-thinking-default.ts
+++ b/src/agents/model-thinking-default.ts
@@ -17,6 +17,7 @@ export function resolveConfiguredThinkingDefault(params: {
   cfg: OpenClawConfig;
   provider: string;
   model: string;
+  agentId?: string;
 }): ThinkLevel | undefined {
   return resolveConfiguredThinkingDefaultCore(params);
 }
@@ -28,6 +29,7 @@ export function resolveThinkingDefault(params: {
   model: string;
   catalog?: ModelCatalogEntry[];
   agentRuntime?: string | null;
+  agentId?: string;
 }): ThinkLevel {
   return resolveThinkingDefaultCore(params);
 }
@@ -39,6 +41,7 @@ export async function resolveThinkingDefaultWithRuntimeCatalog(params: {
   model: string;
   loadRuntimeCatalog: () => Promise<ModelCatalogEntry[]>;
   agentRuntime?: string | null;
+  agentId?: string;
 }): Promise<ThinkLevel> {
   const configuredCatalog = buildConfiguredModelCatalog({ cfg: params.cfg });
   const configuredSelectedEntry = configuredCatalog.find(
diff --git a/src/auto-reply/reply/memory-flush.test.ts b/src/auto-reply/reply/memory-flush.test.ts
index 8f57bde36d95..ee37a6a3f928 100644
--- a/src/auto-reply/reply/memory-flush.test.ts
+++ b/src/auto-reply/reply/memory-flush.test.ts
@@ -305,4 +305,33 @@ describe("Anthropic server compaction host threshold", () => {
       }),
     ).toBe(expected);
   });
+
+  it("uses the selected agent context window for the fallback threshold", () => {
+    const cfg: OpenClawConfig = {
+      agents: {
+        defaults: {
+          params: { anthropicServerCompaction: true },
+          models: {
+            "anthropic/claude-opus-4-7": { params: { context1m: false } },
+          },
+        },
+        entries: {
+          audit: {
+            models: {
+              "anthropic/claude-opus-4-7": { params: { context1m: true } },
+            },
+          },
+        },
+      },
+    };
+
+    expect(
+      resolveResponsesServerCompactionThreshold({
+        cfg,
+        provider: "anthropic",
+        modelId: "claude-opus-4-7",
+        agentId: "audit",
+      }),
+    ).toBe(700_000);
+  });
 });
diff --git a/src/auto-reply/reply/memory-flush.ts b/src/auto-reply/reply/memory-flush.ts
index 7037c599b9f1..08e6fc5b5d01 100644
--- a/src/auto-reply/reply/memory-flush.ts
+++ b/src/auto-reply/reply/memory-flush.ts
@@ -78,7 +78,12 @@ export function resolveResponsesServerCompactionThreshold(params: {
         baseUrl: configuredModel?.baseUrl ?? providerConfig?.baseUrl,
         contextWindow:
           configuredModel?.contextWindow ??
-          resolveMemoryFlushContextWindowTokens({ cfg: params.cfg, provider, modelId }),
+          resolveMemoryFlushContextWindowTokens({
+            cfg: params.cfg,
+            provider,
+            modelId,
+            agentId: params.agentId,
+          }),
       },
       extraParams,
     ).threshold;
@@ -89,6 +94,7 @@ export function resolveResponsesServerCompactionThreshold(params: {
     cfg: params.cfg,
     provider,
     modelId,
+    agentId: params.agentId,
   });
   return resolveOpenAIResponsesServerCompactionPlan(
     {
diff --git a/src/cron/isolated-agent/run-executor.ts b/src/cron/isolated-agent/run-executor.ts
index 97d941534351..384b2e973f53 100644
--- a/src/cron/isolated-agent/run-executor.ts
+++ b/src/cron/isolated-agent/run-executor.ts
@@ -468,6 +468,7 @@ function createCronPromptExecutor(params: {
             cfg: params.cfgWithAgentDefaults,
             provider: providerOverride,
             model: modelOverride,
+            agentId: params.agentId,
           });
         if (
           candidateConfiguredThinkLevel !== "off" &&