From 5ed02c1097e61aa5c3f7df17f5890f57bb68253d Mon Sep 17 00:00:00 2001
From: Peter Steinberger <steipete@gmail.com>
Date: Sun, 5 Apr 2026 18:11:55 +0100
Subject: [PATCH] fix: restore foundry model input repair

---
 src/agents/pi-embedded-runner/model.ts | 44 ++++++++++++++++++++++++++
 src/agents/system-prompt.test.ts       | 10 +++---
 2 files changed, 48 insertions(+), 6 deletions(-)

diff --git a/src/agents/pi-embedded-runner/model.ts b/src/agents/pi-embedded-runner/model.ts
index 66d6c4857d6..314c16bed04 100644
--- a/src/agents/pi-embedded-runner/model.ts
+++ b/src/agents/pi-embedded-runner/model.ts
@@ -178,6 +178,9 @@ function normalizeResolvedModel(params: {
   const normalizedInputModel = {
     ...params.model,
     input: resolveProviderModelInput({
+      provider: params.provider,
+      modelId: params.model.id,
+      modelName: params.model.name,
       input: params.model.input,
     }),
   } as Model<Api>;
@@ -293,7 +296,32 @@ function resolveConfiguredProviderConfig(
   return findNormalizedProviderValue(configuredProviders, provider);
 }
 
+function isLegacyFoundryVisionModelCandidate(params: {
+  provider?: string;
+  modelId?: string;
+  modelName?: string;
+}): boolean {
+  if (params.provider?.trim().toLowerCase() !== "microsoft-foundry") {
+    return false;
+  }
+  const normalizedCandidates = [params.modelId, params.modelName]
+    .filter((value): value is string => typeof value === "string")
+    .map((value) => value.trim().toLowerCase())
+    .filter(Boolean);
+  return normalizedCandidates.some(
+    (candidate) =>
+      candidate.startsWith("gpt-") ||
+      candidate.startsWith("o1") ||
+      candidate.startsWith("o3") ||
+      candidate.startsWith("o4") ||
+      candidate === "computer-use-preview",
+  );
+}
+
 function resolveProviderModelInput(params: {
+  provider?: string;
+  modelId?: string;
+  modelName?: string;
   input?: unknown;
   fallbackInput?: unknown;
 }): Array<"text" | "image"> {
@@ -301,6 +329,13 @@ function resolveProviderModelInput(params: {
   const normalizedInput = Array.isArray(resolvedInput)
     ? resolvedInput.filter((item): item is "text" | "image" => item === "text" || item === "image")
     : [];
+  if (
+    normalizedInput.length > 0 &&
+    !normalizedInput.includes("image") &&
+    isLegacyFoundryVisionModelCandidate(params)
+  ) {
+    return ["text", "image"];
+  }
   return normalizedInput.length > 0 ? normalizedInput : ["text"];
 }
 
@@ -344,6 +379,9 @@ function applyConfiguredProviderOverrides(params: {
     };
   }
   const normalizedInput = resolveProviderModelInput({
+    provider: params.provider,
+    modelId,
+    modelName: configuredModel?.name ?? discoveredModel.name,
     input: configuredModel?.input,
     fallbackInput: discoveredModel.input,
   });
@@ -424,6 +462,9 @@ export function buildInlineProviderModels(
         {
           ...model,
           input: resolveProviderModelInput({
+            provider: trimmed,
+            modelId: model.id,
+            modelName: model.name,
             input: model.input,
           }),
           provider: trimmed,
@@ -605,6 +646,9 @@ function resolveConfiguredFallbackModel(params: {
         baseUrl: requestConfig.baseUrl,
         reasoning: configuredModel?.reasoning ?? false,
         input: resolveProviderModelInput({
+          provider,
+          modelId,
+          modelName: configuredModel?.name ?? modelId,
           input: configuredModel?.input,
         }),
         cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
diff --git a/src/agents/system-prompt.test.ts b/src/agents/system-prompt.test.ts
index 4ea33e7373c..ca9dbb8a695 100644
--- a/src/agents/system-prompt.test.ts
+++ b/src/agents/system-prompt.test.ts
@@ -367,10 +367,8 @@ describe("buildAgentSystemPrompt", () => {
     });
 
     expect(prompt).toContain("sessions_spawn");
-    expect(prompt).toContain(
-      'runtime="acp" requires `agentId` unless `acp.defaultAgent` is configured',
-    );
-    expect(prompt).toContain("not agents_list");
+    expect(prompt).toContain("Set `agentId` explicitly unless `acp.defaultAgent` is configured");
+    expect(prompt).toContain("`subagents`/`agents_list`");
   });
 
   it("guides harness requests to ACP thread-bound spawns", () => {
@@ -778,7 +776,7 @@ describe("buildAgentSystemPrompt", () => {
 
     expect(boundaryIndex).toBeGreaterThan(-1);
     expect(dynamicIndex).toBeGreaterThan(boundaryIndex);
-    expect(heartbeatIndex).toBeGreaterThan(dynamicIndex);
+    expect(heartbeatIndex).toBe(-1);
   });
 
   it("summarizes the message tool when available", () => {
@@ -787,8 +785,8 @@ describe("buildAgentSystemPrompt", () => {
       toolNames: ["message"],
     });
 
-    expect(prompt).toContain("message: Send messages and channel actions");
     expect(prompt).toContain("### message tool");
+    expect(prompt).toContain("Use `message` for proactive sends + channel actions");
     expect(prompt).toContain(`respond with ONLY: ${SILENT_REPLY_TOKEN}`);
   });