diff --git a/doc/DEVELOPING.md b/doc/DEVELOPING.md
index f828a2c85e0..f06bb5c943b 100644
--- a/doc/DEVELOPING.md
+++ b/doc/DEVELOPING.md
@@ -2146,6 +2146,13 @@ Lifecycle, timeout, and interrupt grace settings live under **Advanced Run
 Policy**. Permission selectors with a single valid mode are hidden; a saved
 unsupported mode still exposes remediation.
 
+Saving an existing agent compares AI connection bindings by value, independent
+of PostgreSQL JSONB key order. Identity, thinking-effort and run-policy edits
+avoid the connection-adoption runtime probe when the connection and execution
+selection stay the same. Connection, harness, model, provider, engine and
+environment changes still validate adoption. Explicit runtime tests and
+required Copilot metadata checks keep their existing behavior.
+
 Model catalogs and refresh follow the selected provider. ACPX Claude uses the
 normal Claude catalog and accepts custom model IDs; the exact ID is sent to
 Claude, which can reject unavailable models. Package/version verification is
diff --git a/server/src/__tests__/agent-hire-ai-connections.test.ts b/server/src/__tests__/agent-hire-ai-connections.test.ts
index cba65a86d5a..2b397429aa8 100644
--- a/server/src/__tests__/agent-hire-ai-connections.test.ts
+++ b/server/src/__tests__/agent-hire-ai-connections.test.ts
@@ -9,7 +9,7 @@ import express from "express";
 import request from "supertest";
 import { and, eq } from "drizzle-orm";
 import { afterAll, beforeAll, describe, expect, it, vi } from "vitest";
-import { activityLog, agents, authUsers, companies, companyMemberships, createDb, closeRegisteredClients, heartbeatRuns, issues, plugins, principalPermissionGrants, toolConnectionInstalls } from "@paperclipai/db";
+import { activityLog, agents, authUsers, companies, companyMemberships, createDb, closeRegisteredClients, environments, heartbeatRuns, issues, plugins, principalPermissionGrants, toolConnectionInstalls } from "@paperclipai/db";
 import { type AiConnectionBinding, type AiConnectionPoolMember, type PaperclipPluginManifestV1 } from "@paperclipai/shared";
 import { startEmbeddedPostgresTestDatabase } from "./helpers/embedded-postgres.js";
 import { agentRoutes } from "../routes/agents.js";
@@ -209,6 +209,78 @@ describe("agent-created hires use managed AI connections", () => {
     expect(saved.runtimeConfig.aiConnection).toEqual(f.binding);
   });
 
+  it.each(["shared", "delegated", "responsible_user", "router"] as const)("saves unrelated edits without probing an unchanged %s connection read from PostgreSQL", async (mode) => {
+    const f = await fixture("openai");
+    await db.insert(principalPermissionGrants).values({ companyId: f.companyId, principalType: "user", principalId: f.userId, permissionKey: "agents:configure" });
+    const account = mode === "shared"
+      ? await aiConnectionService(db).save(f.companyId, f.userId, {
+        provider: "openai", method: "api_key", ownership: "shared", name: "Shared save fixture",
+        apiKey: "fixture", agentIds: [f.agentId], allAgents: false,
+      }, "fixture")
+      : f.account;
+    const binding = mode === "router" ? (await poolFixture(f)).binding
+      : mode === "responsible_user" ? f.binding
+        : { provider: "openai", method: "api_key", mode, ...account };
+    const adapterType = mode === "shared" ? "paperclip_runner" : f.adapterType;
+    await db.update(agents).set({ adapterType,
+      ...(adapterType === "paperclip_runner" ? { adapterConfig: { provider: "codex", model: "gpt-5.6-sol" } } : {}),
+      runtimeConfig: { aiConnection: binding },
+    }).where(eq(agents.id, f.agentId));
+    const [before] = await db.select().from(agents).where(eq(agents.id, f.agentId));
+    const app = express();
+    app.use(express.json());
+    app.use((req, _res, next) => {
+      req.actor = { type: "board", userId: f.userId, companyIds: [f.companyId], source: "session" };
+      next();
+    });
+    app.use("/api", agentRoutes(db));
+    app.use(errorHandler);
+    const original = getServerAdapter(adapterType);
+    const probe = vi.fn(async () => { throw new Error("The runtime is unavailable; unrelated edits must still save"); });
+    registerServerAdapter({ ...original, testEnvironment: probe });
+    try {
+      for (const patch of [
+        { title: "Updated title" },
+        { adapterConfig: { reasoningEffort: "high" } },
+        { defaultEnvironmentId: null },
+        { runtimeConfig: { ...before.runtimeConfig, heartbeat: { enabled: false } } },
+      ]) {
+        const response = await request(app).patch(`/api/agents/${f.agentId}`).send(patch);
+        expect(response.status, JSON.stringify(response.body)).toBe(200);
+        expect(response.body.runtimeConfig.aiConnection).toEqual(binding);
+      }
+      expect(probe).not.toHaveBeenCalled();
+      const [saved] = await db.select().from(agents).where(eq(agents.id, f.agentId));
+      expect(saved).toMatchObject({ title: "Updated title", adapterConfig: { reasoningEffort: "high" },
+        runtimeConfig: { aiConnection: binding, heartbeat: { enabled: false } } });
+      expect(await db.select().from(activityLog).where(and(eq(activityLog.entityId, f.agentId), eq(activityLog.action, "agent.updated")))).toHaveLength(4);
+    } finally { unregisterServerAdapter(adapterType); }
+  });
+
+  it.each(["model", "engine", "environment", "harness", "connection"] as const)("probes a changed %s selection and preserves the saved configuration on failure", async (selection) => {
+    const f = await fixture("openai");
+    await db.insert(principalPermissionGrants).values({ companyId: f.companyId, principalType: "user", principalId: f.userId, permissionKey: "agents:configure" });
+    const [environment] = await db.select().from(environments).where(eq(environments.driver, "local"));
+    const adapterType = selection === "harness" ? "paperclip_runner" : f.adapterType;
+    const original = getServerAdapter(adapterType);
+    const probe = vi.fn(async () => ({ adapterType, status: "fail" as const, testedAt: new Date().toISOString(),
+      checks: [{ code: "fixture_runtime_unavailable", level: "error" as const, message: "The selected runtime is unavailable" }],
+    }));
+    registerServerAdapter({ ...original, testEnvironment: probe });
+    const patch = selection === "environment" ? { defaultEnvironmentId: environment.id }
+      : selection === "harness" ? { adapterType, adapterConfig: { provider: "codex", model: "gpt-5.6-sol" } }
+        : selection === "connection" ? { runtimeConfig: { aiConnection: { ...f.binding, mode: "delegated", ...f.account } } }
+        : { adapterConfig: { [selection]: selection === "model" ? "changed-model" : "cli" } };
+    try {
+      const response = await request(f.app).patch(`/api/agents/${f.agentId}`).send(patch);
+      expect(response.status, JSON.stringify(response.body)).toBe(422);
+      expect(probe).toHaveBeenCalledOnce();
+      const [saved] = await db.select().from(agents).where(eq(agents.id, f.agentId));
+      expect(saved).toMatchObject({ adapterType: f.adapterType, adapterConfig: {}, defaultEnvironmentId: null,
+        runtimeConfig: { aiConnection: f.binding } });
+    } finally { unregisterServerAdapter(adapterType); }
+  });
+
   it("does not install a restricted shared connection through pool membership", async () => {
     const f = await fixture("openai");
     const otherOwner = `other-${f.companyId}`;
diff --git a/server/src/routes/agents.ts b/server/src/routes/agents.ts
index e05270bc240..d81f90d21cb 100644
--- a/server/src/routes/agents.ts
+++ b/server/src/routes/agents.ts
@@ -50,6 +50,7 @@ import { executionProjectionForRun, executionProjectionsForRuns } from "../servi
 import { selectDashboardRunIds } from "../services/dashboard-run-selection.js";
 import { Router, type NextFunction, type Request, type Response } from "express";
 import { generateKeyPairSync, randomUUID } from "node:crypto";
+import { isDeepStrictEqual } from "node:util";
 import { readFile, rm } from "node:fs/promises";
 import path from "node:path";
 import type { Db } from "@paperclipai/db";
@@ -5599,7 +5600,7 @@ export function agentRoutes(
     const nextAiBinding = aiRuntimeConnectionBindingSchema.safeParse(requestedRuntimeConfig ? requestedRuntimeConfig.aiConnection : existing.runtimeConfig.aiConnection).data;
     if (nextAiBinding) {
       await assertCanConfigureAgentSetup(req, existing);
-      const changed = JSON.stringify(nextAiBinding) !== JSON.stringify(existing.runtimeConfig.aiConnection);
+      const changed = !isDeepStrictEqual(nextAiBinding, existing.runtimeConfig.aiConnection);
       if (changed && req.actor.type === "agent") {
         await connectionManagementService(db).authorize(req.actor, "connections:profiles", {
           type: "connection_management", companyId: existing.companyId, purpose: "ai", targetAgentId: existing.id,
@@ -5608,10 +5609,17 @@ export function agentRoutes(
         });
       }
       const aiConfig = (patchData.adapterConfig ?? existing.adapterConfig) as Record<string, unknown>;
+      const nextEnvironmentId = Object.prototype.hasOwnProperty.call(patchData, "defaultEnvironmentId")
+        ? patchData.defaultEnvironmentId : existing.defaultEnvironmentId;
+      const runtimeSelectionChanged = requestedAdapterType !== existing.adapterType
+        || nextEnvironmentId !== existing.defaultEnvironmentId
+        || (nextAiBinding.mode !== "router" && ["model", "provider", "acpxAgent", "engine"].some(
+          key => aiConfig[key] !== existing.adapterConfig[key],
+        ));
       if (nextAiBinding.mode !== "router" && !isAiConnectionCompatible(nextAiBinding, requestedAdapterType, aiConfig.model, aiConfig.provider, aiConfig.acpxAgent)) throw unprocessable("Select an AI connection compatible with the new harness and model");
       const copilotConfigurationChanged = requestedAdapterType === "paperclip_runner" && aiConfig.provider === "acpx" && aiConfig.acpxAgent === "copilot"
         && (touchesAdapterConfiguration || Object.prototype.hasOwnProperty.call(patchData, "defaultEnvironmentId"));
-      if (runtimeSettings || changed || copilotConfigurationChanged || (nextAiBinding.mode === "router" && requestedAdapterType !== existing.adapterType)) {
+      if (runtimeSettings || changed || runtimeSelectionChanged || copilotConfigurationChanged) {
         const configuringSetup = isAgentSetupDraft(existing);
         await validateManagedAgentBinding(req, existing.companyId, existing.id, requestedAdapterType, aiConfig, nextAiBinding,
           (patchData.defaultEnvironmentId !== undefined ? patchData.defaultEnvironmentId : existing.defaultEnvironmentId) as string | null,