Merge pull request #1951 from edxeth/feat/custom-agents

feat(config): make custom agents first-class for planning and delegation

src/tools/delegate-task/subagent-resolver.test.ts

@@ -79,4 +79,56 @@ describe("resolveSubagentExecution", () => {
       error: "network timeout",
     })
   })
+
+  test("uses inherited model for custom agents without explicit model", async () => {
+    //#given
+    const args = createBaseArgs({ subagent_type: "translator" })
+    const executorCtx = createExecutorContext(async () => ({
+      data: [{ name: "translator", mode: "subagent" }],
+    }))
+
+    //#when
+    const result = await resolveSubagentExecution(
+      args,
+      executorCtx,
+      "sisyphus",
+      "deep",
+      "openai/gpt-5.3-codex",
+      "anthropic/claude-opus-4-6",
+    )
+
+    //#then
+    expect(result.error).toBeUndefined()
+    expect(result.agentToUse).toBe("translator")
+    expect(result.categoryModel).toEqual({
+      providerID: "openai",
+      modelID: "gpt-5.3-codex",
+    })
+  })
+
+  test("uses system default model when inherited model is unavailable", async () => {
+    //#given
+    const args = createBaseArgs({ subagent_type: "translator" })
+    const executorCtx = createExecutorContext(async () => ({
+      data: [{ name: "translator", mode: "subagent" }],
+    }))
+
+    //#when
+    const result = await resolveSubagentExecution(
+      args,
+      executorCtx,
+      "sisyphus",
+      "deep",
+      undefined,
+      "anthropic/claude-opus-4-6",
+    )
+
+    //#then
+    expect(result.error).toBeUndefined()
+    expect(result.agentToUse).toBe("translator")
+    expect(result.categoryModel).toEqual({
+      providerID: "anthropic",
+      modelID: "claude-opus-4-6",
+    })
+  })
 })

src/tools/delegate-task/subagent-resolver.ts

@@ -15,7 +15,9 @@ export async function resolveSubagentExecution(
   args: DelegateTaskArgs,
   executorCtx: ExecutorContext,
   parentAgent: string | undefined,
-  categoryExamples: string
+  categoryExamples: string,
+  inheritedModel?: string,
+  systemDefaultModel?: string,
 ): Promise<{ agentToUse: string; categoryModel: { providerID: string; modelID: string; variant?: string } | undefined; fallbackChain?: FallbackEntry[]; error?: string }> {
   const { client, agentOverrides } = executorCtx
 
@@ -124,6 +126,16 @@ Create the work plan directly - that's your job as the planning agent.`,
     if (!categoryModel && matchedAgent.model) {
       categoryModel = matchedAgent.model
     }
+
+    if (!categoryModel) {
+      const fallbackModel = inheritedModel ?? systemDefaultModel
+      if (fallbackModel) {
+        const parsedFallback = parseModelString(fallbackModel)
+        if (parsedFallback) {
+          categoryModel = parsedFallback
+        }
+      }
+    }
   } catch (error) {
     const errorMessage = error instanceof Error ? error.message : String(error)
     log("[delegate-task] Failed to resolve subagent execution", {

src/tools/delegate-task/tools.ts

@@ -226,7 +226,14 @@ export function createDelegateTask(options: DelegateTaskToolOptions): ToolDefini
           return executeUnstableAgentTask(args, ctx, options, parentContext, agentToUse, categoryModel, systemContent, actualModel)
         }
       } else {
-        const resolution = await resolveSubagentExecution(args, options, parentContext.agent, categoryExamples)
+        const resolution = await resolveSubagentExecution(
+          args,
+          options,
+          parentContext.agent,
+          categoryExamples,
+          inheritedModel,
+          systemDefaultModel,
+        )
         if (resolution.error) {
           return resolution.error
         }