feat: expose negotiated protocol era and version in MCP server status

.specgit.yaml

@@ -1,12 +1,8 @@
 version: 1
-delivery: open-issues-batch
+delivery: expose-negotiated-protocol
 context:
   kind: branch
-  branch: feat/434-open-issues-batch
+  branch: feat/450-expose-negotiated-protocol
 issues:
-  - 434
-  - 442
-  - 443
-  - 440
-  - 436
-pr: 444
+  - 450
+pr: 451

package.json

@@ -76,7 +76,7 @@
       "semver": "7.7.4",
       "typescript": "5.8.2",
       "@typescript/native-preview": "7.0.0-dev.20251207.1",
-      "zod": "4.1.8",
+      "zod": "^4.2.0",
       "remeda": "2.26.0",
       "sst": "4.13.1",
       "shiki": "4.2.0",
@@ -153,7 +153,6 @@
     "@ai-sdk/google@3.0.73": "patches/@ai-sdk%2Fgoogle@3.0.73.patch",
     "@tanstack/solid-virtual@3.13.28": "patches/@tanstack%2Fsolid-virtual@3.13.28.patch",
     "@pierre/trees@1.0.0-beta.4": "patches/@pierre%2Ftrees@1.0.0-beta.4.patch",
-    "@modelcontextprotocol/sdk@1.29.0": "patches/@modelcontextprotocol%2Fsdk@1.29.0.patch",
     "@tanstack/virtual-core@3.17.0": "patches/@tanstack%2Fvirtual-core@3.17.0.patch"
   }
 }

packages/core/src/v1/config/mcp.ts

@@ -20,6 +20,10 @@ export const Local = Schema.Struct({
   timeout: Schema.optional(PositiveInt).annotate({
     description: "Timeout in ms for MCP server requests. Defaults to 5000 (5 seconds) if not specified.",
   }),
+  protocol: Schema.optional(Schema.Literals(["auto", "legacy", "modern"])).annotate({
+    description:
+      "Protocol era negotiation: 'auto' probes server/discover and falls back to the 2025 initialize handshake, 'legacy' skips the probe and runs the 2025 initialize handshake, 'modern' speaks only 2026-07-28 with no fallback. Defaults to 'auto'.",
+  }),
 }).annotate({ identifier: "McpLocalConfig" })
 export type Local = Schema.Schema.Type<typeof Local>
 
@@ -56,6 +60,10 @@ export const Remote = Schema.Struct({
   timeout: Schema.optional(PositiveInt).annotate({
     description: "Timeout in ms for MCP server requests. Defaults to 5000 (5 seconds) if not specified.",
   }),
+  protocol: Schema.optional(Schema.Literals(["auto", "legacy", "modern"])).annotate({
+    description:
+      "Protocol era negotiation: 'auto' probes server/discover and falls back to the 2025 initialize handshake, 'legacy' skips the probe and runs the 2025 initialize handshake, 'modern' speaks only 2026-07-28 with no fallback. Defaults to 'auto'.",
+  }),
 }).annotate({ identifier: "McpRemoteConfig" })
 export type Remote = Schema.Schema.Type<typeof Remote>
 

packages/opencode/package.json

@@ -40,6 +40,7 @@
     "@tsconfig/bun": "catalog:",
     "@types/babel__core": "7.20.5",
     "@types/bun": "catalog:",
+    "@modelcontextprotocol/server": "2.0.0",
     "@types/cross-spawn": "catalog:",
     "@types/mime-types": "3.0.1",
     "@types/escape-html": "1.0.3",
@@ -84,7 +85,8 @@
     "@effect/platform-node": "catalog:",
     "@ff-labs/fff-bun": "0.9.4",
     "@gitlab/opencode-gitlab-auth": "1.3.3",
-    "@modelcontextprotocol/sdk": "1.29.0",
+    "@modelcontextprotocol/client": "2.0.0",
+    "@modelcontextprotocol/core": "2.0.0",
     "@octokit/graphql": "9.0.2",
     "@octokit/rest": "catalog:",
     "@openauthjs/openauth": "catalog:",

packages/opencode/src/cli/cmd/mcp.ts

@@ -2,10 +2,12 @@ import { cmd } from "./cmd"
 import { ConfigV1 } from "@opencode-ai/core/v1/config/config"
 import { effectCmd } from "../effect-cmd"
 import { Cause } from "effect"
-import { Client } from "@modelcontextprotocol/sdk/client/index.js"
-import { StreamableHTTPClientTransport } from "@modelcontextprotocol/sdk/client/streamableHttp.js"
-import { UnauthorizedError } from "@modelcontextprotocol/sdk/client/auth.js"
-import { LATEST_PROTOCOL_VERSION } from "@modelcontextprotocol/sdk/types.js"
+import {
+  Client,
+  StreamableHTTPClientTransport,
+  UnauthorizedError,
+  LATEST_PROTOCOL_VERSION,
+} from "@modelcontextprotocol/client"
 import * as prompts from "@clack/prompts"
 import { UI } from "../ui"
 import { MCP } from "../../mcp"
@@ -137,7 +139,7 @@ export const McpListCommand = effectCmd({
         statusText = "not initialized"
       } else if (status.status === "connected") {
         statusIcon = "✓"
-        statusText = "connected"
+        statusText = `connected${status.era ? ` · ${status.era}` : ""}${status.protocolVersion ? ` (${status.protocolVersion})` : ""}`
         if (hasOAuth && hasStoredTokens) {
           hint = " (OAuth)"
         }
@@ -787,10 +789,21 @@ export const McpDebugCommand = effectCmd({
           })
 
           try {
-            const client = new Client({
-              name: "opencode-debug",
-              version: InstallationVersion,
-            })
+            const client = new Client(
+              { name: "opencode-debug", version: InstallationVersion },
+              {
+                // Mirror createClient's per-server era mapping so diagnostics
+                // match the runtime connection behavior (#448).
+                versionNegotiation: {
+                  mode:
+                    serverConfig.protocol === "legacy"
+                      ? "legacy"
+                      : serverConfig.protocol === "modern"
+                        ? { pin: "2026-07-28" }
+                        : "auto",
+                },
+              },
+            )
             await client.connect(transport)
             prompts.log.success("Connection successful (already authenticated)")
             await client.close()

packages/opencode/src/mcp/catalog.ts

@@ -1,10 +1,6 @@
-import { Client } from "@modelcontextprotocol/sdk/client/index.js"
-import {
-  CallToolResultSchema,
-  ListToolsResultSchema,
-  ToolSchema,
-  type Tool as MCPToolDef,
-} from "@modelcontextprotocol/sdk/types.js"
+import { ListToolsResultSchema, ToolSchema } from "@modelcontextprotocol/core"
+import { Client } from "@modelcontextprotocol/client"
+import type { Tool as MCPToolDef } from "@modelcontextprotocol/client"
 import { dynamicTool, jsonSchema, type JSONSchema7, type Tool } from "ai"
 import { Effect } from "effect"
 
@@ -56,7 +52,6 @@ export function convertTool(mcpTool: MCPToolDef, client: Client, timeout?: numbe
           name: mcpTool.name,
           arguments: (args || {}) as Record<string, unknown>,
         },
-        CallToolResultSchema,
         {
           resetTimeoutOnProgress: true,
           signal: options.abortSignal,

packages/opencode/src/mcp/elicitation.ts

@@ -18,9 +18,8 @@
  *   ─▶ fire ElicitationResult hook (result | cancelled)
  *   ─▶ respond to server
  */
 import { Effect, Option, Schema } from "effect"
-import type { Client } from "@modelcontextprotocol/sdk/client/index.js"
-import { ElicitRequestSchema } from "@modelcontextprotocol/sdk/types.js"
+import type { Client } from "@modelcontextprotocol/client"
 import { Question } from "@/question"
 import { SettingsHook, type TriggerResult } from "@/hook/settings"
 import { Notification } from "@/notification"
@@ -85,10 +84,7 @@
  * reason. MCP form-mode allows flat objects whose properties are primitive
  * string/number/integer/boolean, optionally with an enum.
  */
-export function classifyProperty(
-  name: string,
-  prop: unknown,
-): { field: FieldSpec } | { reject: string } {
+export function classifyProperty(name: string, prop: unknown): { field: FieldSpec } | { reject: string } {
   if (typeof prop !== "object" || prop === null || Array.isArray(prop))
     return { reject: `property "${name}" must be an object` }
   const p = prop as Record<string, unknown>
@@ -97,19 +93,34 @@
   if (Array.isArray(p.enum)) {
     const enumValues = p.enum.filter((v): v is string => typeof v === "string")
     if (enumValues.length !== p.enum.length) return { reject: `property "${name}" enum must be all strings` }
-    return { field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "enum", enumValues } }
+    return {
+      field: {
+        name,
+        description: typeof p.description === "string" ? p.description : undefined,
+        kind: "enum",
+        enumValues,
+      },
+    }
   }
   if (type === "boolean") {
-    return { field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "boolean" } }
+    return {
+      field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "boolean" },
+    }
   }
   if (type === "string") {
-    return { field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "string" } }
+    return {
+      field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "string" },
+    }
   }
   if (type === "number") {
-    return { field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "number" } }
+    return {
+      field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "number" },
+    }
   }
   if (type === "integer") {
-    return { field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "integer" } }
+    return {
+      field: { name, description: typeof p.description === "string" ? p.description : undefined, kind: "integer" },
+    }
   }
   return { reject: `property "${name}" type "${String(type)}" not supported (flat primitives only)` }
 }
@@ -276,13 +287,11 @@
   // decline without surfacing the Question.
   if (settingsHook) {
     const hookResult = yield* settingsHook
-      .trigger(
-        { event: "Elicitation", prompt: input.message, schema: input.requestedSchema } as never,
-        { sessionID, transcriptPath: "" },
-      )
-      .pipe(
-        Effect.catch(() => Effect.succeed<TriggerResult>({ additionalContexts: [], systemMessages: [] })),
-      )
+      .trigger({ event: "Elicitation", prompt: input.message, schema: input.requestedSchema } as never, {
+        sessionID,
+        transcriptPath: "",
+      })
+      .pipe(Effect.catch(() => Effect.succeed<TriggerResult>({ additionalContexts: [], systemMessages: [] })))
     yield* SettingsHook.landSystemMessages(hookResult as TriggerResult, { sessionID })
     if ((hookResult as TriggerResult).blocked) {
       yield* Effect.logWarning("elicitation declined: hook blocked")
@@ -301,14 +310,12 @@
   // rejection (user dismissed) both resolve to decline; only a validated reply
   // resolves to accept.
   const fields = fieldSpecsFromSchema(input.requestedSchema)
-  const validated = yield* question
-    .ask({ sessionID: SessionID.make(sessionID), questions: mapped.questions })
-    .pipe(
-      // timeoutOption returns None on timeout; timeoutOrElse would also work.
-      Effect.timeoutOption(ELICITATION_TIMEOUT_MS),
-      Effect.map((opt) => (Option.isNone(opt) ? undefined : validateAndCoerce(fields, opt.value))),
-      Effect.catch(() => Effect.succeed<undefined>(undefined)), // user reject (RejectedError) → decline
-    )
+  const validated = yield* question.ask({ sessionID: SessionID.make(sessionID), questions: mapped.questions }).pipe(
+    // timeoutOption returns None on timeout; timeoutOrElse would also work.
+    Effect.timeoutOption(ELICITATION_TIMEOUT_MS),
+    Effect.map((opt) => (Option.isNone(opt) ? undefined : validateAndCoerce(fields, opt.value))),
+    Effect.catch(() => Effect.succeed<undefined>(undefined)), // user reject (RejectedError) → decline
+  )
 
   // ElicitationResult hook fires on resolution (result on accept, cancelled otherwise).
   if (settingsHook) {
@@ -330,17 +337,11 @@
  * Register the elicitation handler on a connected MCP client. The handler is a
  * plain async function (Promise-returning) that bridges into the Effect world.
  */
-export function registerElicitationHandler(
-  client: Client,
-  bridge: import("@/effect/bridge").EffectBridge.Shape,
-) {
-  // Dynamic import keeps the protocol schema lazy — the MCP SDK is only pulled
-  // in when elicitation is actually wired, not at module-eval time of callers.
+export function registerElicitationHandler(client: Client, bridge: import("@/effect/bridge").EffectBridge.Shape) {
   // The handler receives the full JSON-RPC request `{ method, params: {...} }`;
-  // the elicitation fields live under `params`.
-  const handler = async (request: {
-    params?: { message?: string; requestedSchema?: unknown; mode?: string }
-  }) => {
+  // the elicitation fields live under `params`. On 2026-era connections the
+  // client drives input_required retries through this same handler.
+  const handler = async (request: { params?: { message?: string; requestedSchema?: unknown; mode?: string } }) => {
     const params = request.params ?? {}
     const sessionID = SessionContext.sessionID ?? activeSession.at(-1)?.id
     const response = await bridge.promise(
@@ -353,7 +354,5 @@
     )
     return response
   }
-  // The schema is imported eagerly at module load so registration is synchronous
-  // (a lazy dynamic import would race with the first incoming request).
-  client.setRequestHandler(ElicitRequestSchema, handler as never)
+  client.setRequestHandler("elicitation/create", handler as never)
 }