refactor(subagents): share effective model selection resolver

src/agents/model-selection.ts

@@ -1,5 +1,5 @@
 import type { OpenClawConfig } from "../config/config.js";
-import { resolveAgentModelPrimary } from "./agent-scope.js";
+import { resolveAgentConfig, resolveAgentModelPrimary } from "./agent-scope.js";
 import { DEFAULT_MODEL, DEFAULT_PROVIDER } from "./defaults.js";
 import type { ModelCatalogEntry } from "./model-catalog.js";
 import { normalizeGoogleModelId } from "./models-config.providers.js";
@@ -316,6 +316,38 @@ export function resolveDefaultModelForAgent(params: {
   });
 }
 
+export function resolveSubagentConfiguredModelSelection(params: {
+  cfg: OpenClawConfig;
+  agentId: string;
+}): string | undefined {
+  const agentConfig = resolveAgentConfig(params.cfg, params.agentId);
+  return (
+    normalizeModelSelection(agentConfig?.subagents?.model) ??
+    normalizeModelSelection(params.cfg.agents?.defaults?.subagents?.model) ??
+    normalizeModelSelection(agentConfig?.model)
+  );
+}
+
+export function resolveSubagentSpawnModelSelection(params: {
+  cfg: OpenClawConfig;
+  agentId: string;
+  modelOverride?: unknown;
+}): string {
+  const runtimeDefault = resolveDefaultModelForAgent({
+    cfg: params.cfg,
+    agentId: params.agentId,
+  });
+  return (
+    normalizeModelSelection(params.modelOverride) ??
+    resolveSubagentConfiguredModelSelection({
+      cfg: params.cfg,
+      agentId: params.agentId,
+    }) ??
+    normalizeModelSelection(params.cfg.agents?.defaults?.model?.primary) ??
+    `${runtimeDefault.provider}/${runtimeDefault.model}`
+  );
+}
+
 export function buildAllowedModelSet(params: {
   cfg: OpenClawConfig;
   catalog: ModelCatalogEntry[];

src/agents/openclaw-tools.subagents.sessions-spawn.model.e2e.test.ts

@@ -255,6 +255,40 @@ describe("openclaw-tools: subagents (sessions_spawn model + thinking)", () => {
     });
   });
 
+  it("sessions_spawn prefers target agent primary model over global default", async () => {
+    resetSubagentRegistryForTests();
+    callGatewayMock.mockReset();
+    setSessionsSpawnConfigOverride({
+      session: { mainKey: "main", scope: "per-sender" },
+      agents: {
+        defaults: { model: { primary: "minimax/MiniMax-M2.1" } },
+        list: [{ id: "research", model: { primary: "opencode/claude" } }],
+      },
+    });
+    const calls: GatewayCall[] = [];
+    mockPatchAndSingleAgentRun({ calls, runId: "run-agent-primary-model" });
+
+    const tool = await getSessionsSpawnTool({
+      agentSessionKey: "agent:research:main",
+      agentChannel: "discord",
+    });
+
+    const result = await tool.execute("call-agent-primary-model", {
+      task: "do thing",
+    });
+    expect(result.details).toMatchObject({
+      status: "accepted",
+      modelApplied: true,
+    });
+
+    const patchCall = calls.find(
+      (call) => call.method === "sessions.patch" && (call.params as { model?: string })?.model,
+    );
+    expect(patchCall?.params).toMatchObject({
+      model: "opencode/claude",
+    });
+  });
+
   it("sessions_spawn fails when model patch is rejected", async () => {
     resetSubagentRegistryForTests();
     callGatewayMock.mockReset();

src/agents/subagent-spawn.ts

@@ -6,7 +6,7 @@ import { normalizeAgentId, parseAgentSessionKey } from "../routing/session-key.j
 import { normalizeDeliveryContext } from "../utils/delivery-context.js";
 import { resolveAgentConfig } from "./agent-scope.js";
 import { AGENT_LANE_SUBAGENT } from "./lanes.js";
-import { normalizeModelSelection, resolveDefaultModelForAgent } from "./model-selection.js";
+import { resolveSubagentSpawnModelSelection } from "./model-selection.js";
 import { buildSubagentSystemPrompt } from "./subagent-announce.js";
 import { getSubagentDepthFromSessionStore } from "./subagent-depth.js";
 import { countActiveRunsForSession, registerSubagentRun } from "./subagent-registry.js";
@@ -149,16 +149,11 @@ export async function spawnSubagentDirect(
   const childDepth = callerDepth + 1;
   const spawnedByKey = requesterInternalKey;
   const targetAgentConfig = resolveAgentConfig(cfg, targetAgentId);
-  const runtimeDefaultModel = resolveDefaultModelForAgent({
+  const resolvedModel = resolveSubagentSpawnModelSelection({
     cfg,
     agentId: targetAgentId,
+    modelOverride,
   });
-  const resolvedModel =
-    normalizeModelSelection(modelOverride) ??
-    normalizeModelSelection(targetAgentConfig?.subagents?.model) ??
-    normalizeModelSelection(cfg.agents?.defaults?.subagents?.model) ??
-    normalizeModelSelection(cfg.agents?.defaults?.model?.primary) ??
-    normalizeModelSelection(`${runtimeDefaultModel.provider}/${runtimeDefaultModel.model}`);
 
   const resolvedThinkingDefaultRaw =
     readStringParam(targetAgentConfig?.subagents ?? {}, "thinking") ??

src/gateway/sessions-patch.ts

@@ -1,10 +1,10 @@
 import { randomUUID } from "node:crypto";
-import { resolveAgentConfig, resolveDefaultAgentId } from "../agents/agent-scope.js";
+import { resolveDefaultAgentId } from "../agents/agent-scope.js";
 import type { ModelCatalogEntry } from "../agents/model-catalog.js";
 import {
-  normalizeModelSelection,
   resolveAllowedModelRef,
   resolveDefaultModelForAgent,
+  resolveSubagentConfiguredModelSelection,
 } from "../agents/model-selection.js";
 import { normalizeGroupActivation } from "../auto-reply/group-activation.js";
 import {
@@ -62,15 +62,6 @@ function normalizeExecAsk(raw: string): "off" | "on-miss" | "always" | undefined
   return undefined;
 }
 
-function resolveSubagentModelHint(cfg: OpenClawConfig, agentId: string): string | undefined {
-  const agentConfig = resolveAgentConfig(cfg, agentId);
-  return (
-    normalizeModelSelection(agentConfig?.subagents?.model) ??
-    normalizeModelSelection(cfg.agents?.defaults?.subagents?.model) ??
-    normalizeModelSelection(agentConfig?.model)
-  );
-}
-
 export async function applySessionsPatchToStore(params: {
   cfg: OpenClawConfig;
   store: Record<string, SessionEntry>;
@@ -84,7 +75,7 @@ export async function applySessionsPatchToStore(params: {
   const sessionAgentId = normalizeAgentId(parsedAgent?.agentId ?? resolveDefaultAgentId(cfg));
   const resolvedDefault = resolveDefaultModelForAgent({ cfg, agentId: sessionAgentId });
   const subagentModelHint = isSubagentSessionKey(storeKey)
-    ? resolveSubagentModelHint(cfg, sessionAgentId)
+    ? resolveSubagentConfiguredModelSelection({ cfg, agentId: sessionAgentId })
     : undefined;
 
   const existing = store[storeKey];