feat: model dual-era ChatGPT protocol selection

mcpjam-inspector/client/src/components/connection/ServerDetailModal.tsx

@@ -92,7 +92,7 @@ interface ServerDetailModalProps {
    * Undefined = no host-level pin = "Legacy · default" attribution on
    * the chip.
    */
-  hostDefaultMcpProtocolVersion?: McpProtocolVersion;
+  hostDefaultMcpProtocolVersion?: McpProtocolVersion | "auto";
   /** Project default XAA test identity — shown as override placeholders. */
   projectXaaDefaultIdentity?: { subject: string; email: string } | null;
 }
@@ -176,8 +176,12 @@ export function ServerDetailModal({
   // without forcing the Servers tab to also wire up the provider just
   // for the chip's source attribution.
   const activeMcpProfile = useActiveMcpProfile();
-  const resolvedHostDefaultMcpProtocolVersion: McpProtocolVersion | undefined =
+  const storedHostDefaultMcpProtocolVersion =
     hostDefaultMcpProtocolVersion ?? activeMcpProfile?.mcpProtocolVersion;
+  const resolvedHostDefaultMcpProtocolVersion: McpProtocolVersion | undefined =
+    storedHostDefaultMcpProtocolVersion === "auto"
+      ? undefined
+      : storedHostDefaultMcpProtocolVersion;
   const canEditMcpProtocolVersionOverride = Boolean(
     canQueryProjectServerConfig &&
       serverId &&

mcpjam-inspector/client/src/components/hosts/redesigned/focus/ProtocolTab.tsx

@@ -42,10 +42,9 @@ import type { HostAttentionIssue } from "../types";
 import { useJsonDraftBuffer } from "./useJsonDraftBuffer";
 
 /**
- * "auto" is the UI-only sentinel for "no pin stored" — it maps to
- * `mcpProfile.mcpProtocolVersion === undefined`, NOT to a wire literal.
- * Deliberately not labelled with a version number: absence means the SDK
- * picks the version at connect time, so hardcoding a revision into that
+ * "auto" is a stored selection policy, NOT a wire literal. The SDK negotiates
+ * at connect time and never emits the string itself. Deliberately not labelled
+ * with a version number: hardcoding a revision into that
  * label would go stale the moment the SDK's default moves (the sequenced
  * Phase-5 `versionNegotiation: 'auto'` activation) without anything in
  * this file changing.
@@ -124,23 +123,20 @@ const HOST_PROTOCOL_OPTIONS: Array<{
 /**
  * Which versions this client may actually be pinned to.
  *
- * The backend refuses to store a STATEFUL pin the client does not also
+ * The backend refuses to store a concrete pin the client does not also
  * advertise in `initialize.supportedProtocolVersions` — the SDK's
  * `ConflictingProtocolVersionPin` rule in `canonicalizeMcpProfile`. Presets
  * carry that list (VS Code ships `["2025-11-25"]`), so offering every version
  * on those clients produced choices that could only fail at Save with an
  * opaque "Server Error". Offer what actually saves instead.
  *
  * The advertised list is the whole answer, INCLUDING for stateless revisions.
- * The backend only validates stateful pins (stateless ones skip the initialize
- * handshake, so `ConflictingProtocolVersionPin` never fires for them), but
- * "the backend would accept it" is not the same as "this client speaks it":
- * offering `2026-07-28` on a client that never advertised it emulates a
+ * Offering `2026-07-28` on a client that never advertised it would emulate a
  * product capability that does not exist. A client supports a revision when it
  * lists that revision — there is no separate stateless-support flag.
  *
  * Exempt from the filter:
- * - `"auto"`, which stores no pin at all and so claims nothing.
+ * - `"auto"`, which is a negotiation policy rather than a concrete pin.
  * - The stored value, so a row already pinned outside its own advertised list
  *   keeps rendering its selection instead of silently reading as "Automatic".
  *   Same don't-strand-the-user rule as the policy controls further down.
@@ -226,7 +222,7 @@ type ProtocolDoc = {
    * persistence; per-server pins live on the server card's Connection
    * overrides section.
    */
-  mcpProtocolVersion?: McpProtocolVersion;
+  mcpProtocolVersion?: HostProtocolDropdownValue;
   /**
    * Whether the simulated client mirrors `x-mcp-header` tool arguments into
    * `Mcp-Param-*` request headers (SEP-2243, 2026-07-28). Absent → `"mirror"`,
@@ -529,14 +525,13 @@ export function applyJsonToDraft(
     if (cleaned.length > 0) supportedProtocolVersions = cleaned;
   }
 
-  // mcpProtocolVersion — membership-gate via `isKnownProtocolVersion`
-  // so typo strings fall back to `undefined` (= "SDK default") rather
-  // than slipping through to the SDK's open-routing predicate. Absent
-  // / wrong type also collapses to undefined for the same canonical-
-  // hash-stability reason documented in the type.
-  let mcpProtocolVersion: McpProtocolVersion | undefined;
+  // `auto` is a stored selection policy; every other accepted value is a
+  // concrete wire revision. Typo strings still collapse to undefined.
+  let mcpProtocolVersion: HostProtocolDropdownValue | undefined;
   const rawProtocolVersion = parsed.mcpProtocolVersion;
-  if (
+  if (rawProtocolVersion === "auto") {
+    mcpProtocolVersion = "auto";
+  } else if (
     typeof rawProtocolVersion === "string" &&
     isKnownProtocolVersion(rawProtocolVersion)
   ) {
@@ -670,8 +665,10 @@ export function ProtocolTab({
   // "Automatic" — matching what the connect path does with them anyway.
   const storedProtocolVersion = draft.mcpProfile?.mcpProtocolVersion;
   const selectedDropdownValue: HostProtocolDropdownValue =
-    storedProtocolVersion !== undefined &&
-    isKnownProtocolVersion(storedProtocolVersion)
+    storedProtocolVersion === "auto"
+      ? "auto"
+      : storedProtocolVersion !== undefined &&
+        isKnownProtocolVersion(storedProtocolVersion)
       ? storedProtocolVersion
       : "auto";
 
@@ -689,23 +686,20 @@ export function ProtocolTab({
   );
   const protocolOptionsRestricted =
     protocolOptions.length < HOST_PROTOCOL_OPTIONS.length;
-  // A stored stateful pin outside the advertised list — a legacy row, or one
+  // A stored concrete pin outside the advertised list — a legacy row, or one
   // hand-edited in the JSON. Its option is force-kept (see the helper), which
   // can pad the list back to full length, so this must be detected directly
   // rather than inferred from the option count. Saving such a draft throws
   // `ConflictingProtocolVersionPin`; warn before Save does.
   const selectedPinUnadvertised =
     selectedDropdownValue !== "auto" &&
-    !isStatelessProtocolVersion(selectedDropdownValue) &&
     advertisedProtocolVersions !== undefined &&
     advertisedProtocolVersions.length > 0 &&
     !advertisedProtocolVersions.includes(selectedDropdownValue);
 
-  // Dropdown handler. Writes through to `draft.mcpProfile.mcpProtocolVersion`
-  // directly (parallel to the JSON editor's applyJsonToDraft path) so the
-  // JSON view round-trips immediately. Maps the UI-only "default" sentinel
-  // to `undefined` — preserves canonical-hash stability so the SDK can
-  // upgrade its default version without churning every stored host config.
+  // Dropdown handler. `undefined` here means the user selected Automatic;
+  // persist the explicit policy so ChatGPT's default can differ from a legacy
+  // row whose field is genuinely absent.
   const setProtocolVersion = (next: McpProtocolVersion | undefined) => {
     const warning = legacyProtocolSupportWarning(
       draft.hostStyle,
@@ -736,7 +730,7 @@ export function ProtocolTab({
       const updated: HostConfigMcpProfileV1 = {
         ...base,
         initialize,
-        mcpProtocolVersion: next,
+        mcpProtocolVersion: next ?? "auto",
       };
       return {
         ...prev,
@@ -870,7 +864,7 @@ export function ProtocolTab({
         <div className="flex items-center gap-3">
           <span
             className="text-[12px] font-medium"
-            title="Automatic: store no pin — MCPJam picks the wire version at connect time. Any other choice pins that exact revision for every server on this client."
+            title="Automatic: negotiate at connect time. Any other choice pins that exact revision for every server on this client."
           >
             {fProtocolVersion.label}
           </span>
@@ -905,7 +899,7 @@ export function ProtocolTab({
             materially, so they get their own copy: a stateless pin has no
             legacy fallback, while a stateful pin narrows the initialize
             handshake to that one version. "Automatic" gets no line — the
-            absence of a pin needs no explanation and keeps the panel quiet in
+            selection policy needs no extra explanation and keeps the panel quiet in
             the default state. */}
         {selectedDropdownValue !== "auto" && (
           <p className="mt-1.5 text-[11px] leading-snug text-muted-foreground">
@@ -917,8 +911,7 @@ export function ProtocolTab({
         {/* Without this line a preset-backed client reads as a broken control:
             the missing revisions look arbitrary, and the list that removed them
             is invisible unless the JSON editor below is open. Name both. The
-            claim is scoped to pre-2026 revisions — stateless versions skip the
-            initialize handshake and stay pinnable regardless of the list. */}
+            list constrains every concrete pin, including 2026. */}
         {protocolOptionsRestricted && (
           <p className="mt-1.5 text-[11px] leading-snug text-muted-foreground">
             This client advertises{" "}

mcpjam-inspector/client/src/components/hosts/redesigned/focus/__tests__/ProtocolTab.versionDropdown.test.tsx

@@ -118,7 +118,7 @@ describe("ProtocolTab protocol-version dropdown", () => {
     expect(screen.getByTestId("pin").textContent).toBe("2025-06-18");
   });
 
-  it("defaults an unpinned host to Automatic and stores no pin", () => {
+  it("renders a legacy unpinned host as Automatic without rewriting it", () => {
     render(<Harness initial={emptyHostConfigInputV2()} />);
 
     expect(
@@ -127,7 +127,7 @@ describe("ProtocolTab protocol-version dropdown", () => {
     expect(screen.getByTestId("pin").textContent).toBe("<undefined>");
   });
 
-  it("selecting Latest pins 2026-07-28; returning to Automatic clears it", async () => {
+  it("selecting Latest pins 2026-07-28; returning to Automatic stores auto", async () => {
     const user = userEvent.setup();
     render(<Harness initial={emptyHostConfigInputV2()} />);
 
@@ -137,14 +137,12 @@ describe("ProtocolTab protocol-version dropdown", () => {
     await user.click(screen.getByRole("option", { name: /Latest/i }));
     expect(screen.getByTestId("pin").textContent).toBe("2026-07-28");
 
-    // Back to Automatic must restore ABSENCE, not a 2025 literal — a stored
-    // literal would churn the canonical config hash against every
-    // pre-feature row.
+    // Automatic is an explicit selection policy, not a wire protocol literal.
     await user.click(
       screen.getByRole("combobox", { name: "MCP protocol version" })
     );
     await user.click(screen.getByRole("option", { name: "Automatic" }));
-    expect(screen.getByTestId("pin").textContent).toBe("<undefined>");
+    expect(screen.getByTestId("pin").textContent).toBe("auto");
   });
 
   it("shows a stored legacy pin as itself instead of collapsing it", () => {
@@ -178,7 +176,7 @@ describe("ProtocolTab protocol-version dropdown", () => {
 });
 
 /**
- * The backend (`canonicalizeMcpProfile`) refuses to store a STATEFUL pin that
+ * The backend (`canonicalizeMcpProfile`) refuses to store a concrete pin that
  * is absent from `initialize.supportedProtocolVersions` —
  * `ConflictingProtocolVersionPin`. Preset-backed clients carry that list, so
  * offering the full set on them produced choices that failed at Save with an
@@ -261,11 +259,9 @@ describe("ProtocolTab dropdown vs. the client's advertised versions", () => {
       screen.getByRole("combobox", { name: "MCP protocol version" })
     );
 
-    // The backend WOULD accept a stateless pin here (it only validates
-    // stateful ones), but accepting it is not the same as the client speaking
-    // it: offering 2026-07-28 to a client that never advertised it emulates a
-    // capability the real product does not have. Only Automatic — which claims
-    // nothing — survives alongside the advertised revision.
+    // Every concrete pin is constrained by the advertised support list,
+    // including the stateless 2026 revision. Automatic remains available as
+    // the negotiation policy.
     expect(
       (await screen.findAllByRole("option")).map((o) => o.textContent)
     ).toEqual(["Automatic", "November (2025-11-25)"]);
@@ -390,19 +386,16 @@ describe("ProtocolTab dropdown vs. the client's advertised versions", () => {
     ).toBeInTheDocument();
   });
 
-  it("does not warn on an advertised or stateless pin", () => {
+  it("does not warn on an advertised pin and warns on any unadvertised pin", () => {
     // Advertised pin: fine.
     const { unmount } = render(
       <Harness initial={withAdvertised(["2025-11-25"], "2025-11-25")} />
     );
     expect(screen.queryByText(/does not advertise/)).toBeNull();
     unmount();
 
-    // Stateless pin: the dropdown no longer OFFERS an unadvertised stateless
-    // version, but a config that already carries one still saves — the backend
-    // rule never reaches it. The warning speaks only to save failure, so it
-    // must stay silent here rather than crying wolf.
+    // The stateless wire path also has to match the client's advertised list.
     render(<Harness initial={withAdvertised(["2025-11-25"], "2026-07-28")} />);
-    expect(screen.queryByText(/does not advertise/)).toBeNull();
+    expect(screen.getByText(/does not advertise/)).toBeInTheDocument();
   });
 });

mcpjam-inspector/client/src/lib/__tests__/client-config-v2-mcp-profile.test.ts

@@ -73,14 +73,12 @@ describe("resolveClientInfo", () => {
   });
 
   test("returns undefined when initialize.clientInfo is unset (even with profile present)", () => {
-    expect(
-      resolveClientInfo({ profileVersion: 1 }),
-    ).toBeUndefined();
+    expect(resolveClientInfo({ profileVersion: 1 })).toBeUndefined();
     expect(
       resolveClientInfo({
         profileVersion: 1,
         initialize: { supportedProtocolVersions: ["2025-11-25"] },
-      }),
+      })
     ).toBeUndefined();
   });
 
@@ -152,14 +150,13 @@ describe("emptyHostConfigInputV2 mcpProfile handling", () => {
     // (Hit this exact bug during initial test writing — shared mutable
     // fixtures + an aliasing assertion is a foot-gun.)
     const source = JSON.parse(
-      JSON.stringify(SAMPLE_PROFILE),
+      JSON.stringify(SAMPLE_PROFILE)
     ) as HostConfigMcpProfileV1;
     const partial: Partial<HostConfigInputV2> = { mcpProfile: source };
     const input = emptyHostConfigInputV2(partial);
     expect(input.mcpProfile).toEqual(SAMPLE_PROFILE);
     // Mutate the source — input must be unaffected.
-    (source.initialize!.clientInfo as Record<string, unknown>).name =
-      "mutated";
+    (source.initialize!.clientInfo as Record<string, unknown>).name = "mutated";
     expect(input.mcpProfile?.initialize?.clientInfo?.name).toBe("chatgpt");
   });
 });
@@ -173,7 +170,7 @@ describe("hostConfigDtoToInput mcpProfile round-trip", () => {
   test("DTO with mcpProfile → input with cloned mcpProfile", () => {
     // Same aliasing-test trap — deep-clone the fixture before mutation.
     const sourceProfile = JSON.parse(
-      JSON.stringify(SAMPLE_PROFILE),
+      JSON.stringify(SAMPLE_PROFILE)
     ) as HostConfigMcpProfileV1;
     const dto = { ...BASE_DTO, mcpProfile: sourceProfile };
     const input = hostConfigDtoToInput(dto);
@@ -282,7 +279,7 @@ describe("hostConfigInputsEqual mcpProfile semantics", () => {
 });
 
 describe("resolveEffectiveCompatRuntime — per-method capability matrix", () => {
-  test('host style with `compatRuntime.openaiApps: false` resolves to `{ injected: false }` regardless of overrides', () => {
+  test("host style with `compatRuntime.openaiApps: false` resolves to `{ injected: false }` regardless of overrides", () => {
     // Claude doesn't inject the shim. Per-method overrides without
     // injection are meaningless — the resolver must short-circuit.
     const result = resolveEffectiveCompatRuntime({
@@ -391,20 +388,20 @@ describe("resolveEffectiveCompatRuntime — per-method capability matrix", () =>
 // but the runtime always uses the host default).
 describe("resolveEffectiveMcpProtocolVersion — per-server override precedence", () => {
   test("server override wins over host default", () => {
-    expect(
-      resolveEffectiveMcpProtocolVersion("2026-07-28", "2025-11-25"),
-    ).toBe("2026-07-28");
+    expect(resolveEffectiveMcpProtocolVersion("2026-07-28", "2025-11-25")).toBe(
+      "2026-07-28"
+    );
   });
 
   test("host default applies when no server override", () => {
     expect(resolveEffectiveMcpProtocolVersion(undefined, "2025-11-25")).toBe(
-      "2025-11-25",
+      "2025-11-25"
     );
   });
 
   test("returns undefined when neither layer has an opinion (SDK default semantics)", () => {
     expect(resolveEffectiveMcpProtocolVersion(undefined, undefined)).toBe(
-      undefined,
+      undefined
     );
   });
 
@@ -413,9 +410,9 @@ describe("resolveEffectiveMcpProtocolVersion — per-server override precedence"
     // migration test, one legacy server overridden back to 2025-11-25.
     // The override must reach the connect path or the legacy server
     // will fail with -32004.
-    expect(
-      resolveEffectiveMcpProtocolVersion("2025-11-25", "2026-07-28"),
-    ).toBe("2025-11-25");
+    expect(resolveEffectiveMcpProtocolVersion("2025-11-25", "2026-07-28")).toBe(
+      "2025-11-25"
+    );
   });
 });
 
@@ -425,7 +422,10 @@ describe("isMcpProfileEmpty (shared by every profile write path)", () => {
     // inlined at four write sites, so a field one of them didn't know about
     // silently collapsed the profile — losing the user's setting on save.
     for (const profile of [
-      { profileVersion: 1 as const, paginationTraversal: "firstPageOnly" as const },
+      {
+        profileVersion: 1 as const,
+        paginationTraversal: "firstPageOnly" as const,
+      },
       { profileVersion: 1 as const, mrtrSupport: "none" as const },
       { profileVersion: 1 as const, toolParamHeaderMirroring: "omit" as const },
     ]) {
@@ -436,20 +436,18 @@ describe("isMcpProfileEmpty (shared by every profile write path)", () => {
   it("treats an EMPTY initialize envelope as empty", () => {
     // The canonicalizer drops an empty `initialize`, so persisting a profile
     // that holds only one would mint a row hashing identically to no profile.
-    expect(
-      isMcpProfileEmpty({ profileVersion: 1, initialize: {} }),
-    ).toBe(true);
+    expect(isMcpProfileEmpty({ profileVersion: 1, initialize: {} })).toBe(true);
     expect(
       isMcpProfileEmpty({
         profileVersion: 1,
         initialize: { supportedProtocolVersions: [] },
-      }),
+      })
     ).toBe(true);
     expect(
       isMcpProfileEmpty({
         profileVersion: 1,
         initialize: { supportedProtocolVersions: ["2026-07-28"] },
-      }),
+      })
     ).toBe(false);
   });
 

mcpjam-inspector/client/src/lib/host-config-field-schema.ts

@@ -471,15 +471,16 @@ export const HOST_CONFIG_FIELDS: ReadonlyArray<HostConfigFieldDef> = [
     label: "Protocol version",
     path: "mcpProfile.mcpProtocolVersion",
     description:
-      "Host default pin. Per-server overrides win. Undefined = SDK chooses at request time.",
+      'Host default selection. "auto" negotiates at connect time; concrete versions pin that exact era. Per-server overrides win.',
     kind: {
       kind: "enum",
       options: [
+        "auto",
         "2025-03-26",
         "2025-06-18",
         "2025-11-25",
         "2026-07-28",
-      ] as ReadonlyArray<McpProtocolVersion>,
+      ] as ReadonlyArray<McpProtocolVersion | "auto">,
     },
     read: (cfg) => mcpProfile(cfg)?.mcpProtocolVersion,
   },