fix(tui): summarize MCP sidebar errors

Co-authored-by: James Long <17031+jlongster@users.noreply.github.com>

packages/core/src/aisdk.ts

@@ -413,7 +413,7 @@ function mapBodyToProviderOptions(model: Info, packageName: string) {
 function callOptions(request: LLMRequest): LanguageModelV3CallOptions {
   return {
     prompt: prompt(request),
-    maxOutputTokens: request.generation?.maxTokens ?? request.model.route.defaults.limits?.output,
+    maxOutputTokens: request.generation?.maxTokens,
     temperature: request.generation?.temperature,
     stopSequences: request.generation?.stop === undefined ? undefined : [...request.generation.stop],
     topP: request.generation?.topP,

packages/core/src/filesystem/location-watcher.ts

@@ -71,6 +71,14 @@ const layer = Layer.effect(
           yield* updates.pipe(Stream.runForEach(publish), Effect.forkScoped)
         }
       }
+      if (location.vcs?.type === "hg") {
+        const store = location.vcs.store
+        const vcs = yield* fs.realPath(store).pipe(Effect.catch(() => Effect.succeed(store)))
+        if (!config.includes(".hg") && !config.includes(vcs)) {
+          const updates = yield* watcher.subscribe({ path: path.join(vcs, "branch"), type: "file" })
+          yield* updates.pipe(Stream.runForEach(publish), Effect.forkScoped)
+        }
+      }
     }).pipe(
       Effect.withSpan("LocationWatcher.start", { attributes: { directory: location.directory } }),
       Effect.catchCause((cause) => Effect.logError("failed to init location watcher service", { cause })),

packages/core/src/model-resolver.ts

@@ -209,12 +209,9 @@ export const fromCatalogModel = (
       body: Provider.mergeOverlay(mapping?.body, resolved.body),
       limits: { context: resolved.limit.context, input: resolved.limit.input, output: resolved.limit.output },
     }
-    const finalized = specifier.startsWith("@opencode-ai/ai/providers/amazon-bedrock")
-      ? yield* withBedrockCredentials(settings, configured)
-      : settings
     return yield* Effect.try({
       try: () => {
-        const runtime = module.model(resolved.modelID ?? resolved.id, finalized)
+        const runtime = module.model(resolved.modelID ?? resolved.id, settings)
         return LanguageModel.update(runtime, {
           provider: resolved.providerID,
           compatibility: resolved.compatibility
@@ -248,53 +245,6 @@ const withoutNativeAuthSettings = (settings: Record<string, unknown>) => {
   return rest
 }
 
-// Chain providers cache and refresh resolved credentials internally, so reuse one per
-// AWS profile instead of re-walking SSO, shared config, and instance metadata each turn.
-const bedrockChains = new Map<
-  string,
-  () => Promise<{ accessKeyId: string; secretAccessKey: string; sessionToken?: string }>
->()
-
-// Bedrock signs requests with static credentials captured at model build time; the route
-// never refreshes them. Model resolution runs before every provider turn, so falling back
-// to the AWS default chain (env, shared config, SSO, process, instance roles) here keeps
-// credentials fresh without persisting them.
-const withBedrockCredentials = Effect.fnUntraced(function* (
-  settings: Readonly<Record<string, unknown>>,
-  configured: Readonly<Record<string, unknown>>,
-) {
-  const base =
-    typeof settings.region !== "string" && process.env.AWS_REGION
-      ? { ...settings, region: process.env.AWS_REGION }
-      : settings
-  if (typeof base.apiKey === "string" || base.credentials !== undefined) return base
-  if (process.env.AWS_BEARER_TOKEN_BEDROCK) return { ...base, apiKey: process.env.AWS_BEARER_TOKEN_BEDROCK }
-  const profile = typeof configured.profile === "string" ? configured.profile : process.env.AWS_PROFILE
-  const identity = yield* Effect.tryPromise(() => {
-    const chain = bedrockChains.get(profile ?? "")
-    if (chain) return chain()
-    return import("@aws-sdk/credential-providers").then((mod) => {
-      const created = mod.fromNodeProviderChain(profile === undefined ? {} : { profile })
-      bedrockChains.set(profile ?? "", created)
-      return created()
-    })
-  }).pipe(
-    Effect.catch((cause) =>
-      Effect.logWarning("AWS credential chain resolution failed for Bedrock", { cause }).pipe(Effect.as(undefined)),
-    ),
-  )
-  if (!identity) return base
-  return {
-    ...base,
-    credentials: {
-      region: typeof base.region === "string" ? base.region : "us-east-1",
-      accessKeyId: identity.accessKeyId,
-      secretAccessKey: identity.secretAccessKey,
-      ...(identity.sessionToken === undefined ? {} : { sessionToken: identity.sessionToken }),
-    },
-  }
-})
-
 const unsupported = (model: Info) =>
   new UnsupportedPackageError({
     providerID: model.providerID,

packages/core/src/vcs.ts

@@ -1,12 +1,16 @@
 export * as Vcs from "./vcs"
 
-import { Context, Effect, Layer } from "effect"
+import path from "path"
+import { Context, Effect, Layer, Stream } from "effect"
 import { FileDiff } from "@opencode-ai/schema/file-diff"
+import { FileSystem } from "@opencode-ai/schema/filesystem"
 import { FileStatus, Info, Mode } from "@opencode-ai/schema/vcs"
+import { VcsEvent } from "@opencode-ai/schema/vcs-event"
 import { makeLocationNode } from "@opencode-ai/util/effect/app-node"
 import { FSUtil } from "@opencode-ai/util/fs-util"
 import { Location } from "./location"
 import { AppProcess } from "@opencode-ai/util/process"
+import { Bus } from "./bus"
 import { VcsGit } from "./vcs/git"
 import { VcsHg } from "./vcs/hg"
 
@@ -39,11 +43,35 @@ const layer = Layer.effect(
     const proc = yield* AppProcess.Service
     const fs = yield* FSUtil.Service
     const location = yield* Location.Service
+    const bus = yield* Bus.Service
     const impl = adapter(proc, fs, location)
+    const vcs = location.vcs
+    const state = { info: impl ? yield* impl.info() : { branch: {} } satisfies Info }
+
+    if (vcs && impl) {
+      const store = yield* fs.realPath(vcs.store).pipe(Effect.catch(() => Effect.succeed(vcs.store)))
+      const isBranchMetadata =
+        vcs.type === "git"
+          ? (file: string) => path.basename(file) === "HEAD" && FSUtil.contains(store, file)
+          : (file: string) => path.resolve(file) === path.join(store, "branch")
+      yield* bus.subscribe(FileSystem.Event.Changed).pipe(
+        Stream.filter((event) => isBranchMetadata(event.data.file)),
+        Stream.runForEach((event) =>
+          Effect.gen(function* () {
+            const next = yield* impl.info()
+            const changed = state.info.branch.current !== next.branch.current
+            state.info = next
+            if (!changed) return
+            yield* bus.publish(VcsEvent.BranchUpdated, { branch: next.branch.current })
+          }).pipe(Effect.withSpan("Vcs.refreshBranch", { attributes: { file: event.data.file } })),
+        ),
+        Effect.forkScoped({ startImmediately: true }),
+      )
+    }
+
     return Service.of({
       info: Effect.fn("Vcs.info")(function* () {
-        if (!impl) return { branch: {} }
-        return yield* impl.info()
+        return state.info
       }),
       status: Effect.fn("Vcs.status")(function* () {
         if (!impl) return []
@@ -60,5 +88,5 @@ const layer = Layer.effect(
 export const node = makeLocationNode({
   service: Service,
   layer: layer,
-  deps: [AppProcess.node, FSUtil.node, Location.node],
+  deps: [AppProcess.node, FSUtil.node, Location.node, Bus.node],
 })

packages/core/test/aisdk.test.ts

@@ -98,6 +98,23 @@ it.effect("projects request settings, headers, and body overlays", () =>
   }),
 )
 
+it.effect("leaves max output tokens unset when the request omits them", () =>
+  Effect.gen(function* () {
+    const aisdk = yield* AISDK.Service
+    yield* aisdk.hook.sdk((event) => {
+      event.sdk = { languageModel: () => ({ provider: event.model.providerID }) }
+    })
+
+    const resolved = yield* aisdk.model({
+      ...model("@openrouter/ai-sdk-provider"),
+      limit: { context: 500_000, output: 500_000 },
+    })
+    const prepared = yield* compileRequest(LLM.request({ model: resolved, prompt: "Hello" }))
+
+    expect(prepared.body.maxOutputTokens).toBeUndefined()
+  }),
+)
+
 it.effect("maps pro reasoning bodies to AI SDK provider options", () =>
   Effect.gen(function* () {
     const aisdk = yield* AISDK.Service

packages/core/test/filesystem/watcher.test.ts

@@ -153,12 +153,16 @@ function provide(directory: string, vcs?: Location.Interface["vcs"]) {
 
 function withTmp<A, E, R>(
   f: (directory: string, vcs?: Location.Interface["vcs"]) => Effect.Effect<A, E, R>,
-  options?: { git?: boolean; init?: (directory: string) => Promise<void> },
+  options?: { vcs?: "git" | "hg"; init?: (directory: string) => Promise<void> },
 ) {
   return Effect.acquireRelease(
     Effect.promise(async () => {
       const tmp = await tmpdir()
-      if (!options?.git) return { tmp, vcs: undefined }
+      if (options?.vcs === "hg") {
+        await fs.mkdir(path.join(tmp.path, ".hg"))
+        return { tmp, vcs: { type: "hg" as const, store: AbsolutePath.make(path.join(tmp.path, ".hg")) } }
+      }
+      if (options?.vcs !== "git") return { tmp, vcs: undefined }
       await $`git init`.cwd(tmp.path).quiet()
       await $`git config core.fsmonitor false`.cwd(tmp.path).quiet()
       await $`git config commit.gpgsign false`.cwd(tmp.path).quiet()
@@ -292,7 +296,7 @@ describeWatcher("LocationWatcher", () => {
             })
           }
         }),
-      { git: true },
+      { vcs: "git" },
     ),
   )
 
@@ -322,7 +326,7 @@ describeWatcher("LocationWatcher", () => {
             }),
           )
         }),
-      { git: true },
+      { vcs: "git" },
     ),
   )
 
@@ -359,7 +363,7 @@ describeWatcher("LocationWatcher", () => {
               .pipe(Effect.andThen(Effect.promise(() => $`git add .`.cwd(directory).quiet())), Effect.asVoid),
           )
         }),
-      { git: true },
+      { vcs: "git" },
     ),
   )
 
@@ -376,7 +380,7 @@ describeWatcher("LocationWatcher", () => {
             yield* nextUpdate((event) => event.file === head, fs.writeFileString(head, `ref: refs/heads/${branch}\n`)),
           ).toMatchObject({ file: head })
         }),
-      { git: true },
+      { vcs: "git" },
     ),
   )
 
@@ -401,7 +405,7 @@ describeWatcher("LocationWatcher", () => {
             ).toEqual({ file: path.join(actual, "HEAD"), event: "change" })
           }),
         {
-          git: true,
+          vcs: "git",
           init: async (directory) => {
             const actual = path.join(directory, "..", `actual_${path.basename(directory)}`)
             await fs.rename(path.join(directory, ".git"), actual)
@@ -411,4 +415,19 @@ describeWatcher("LocationWatcher", () => {
       ),
     )
   })
+
+  it.live("publishes .hg/branch events", () =>
+    withTmp(
+      (directory) =>
+        Effect.gen(function* () {
+          const fs = yield* FSUtil.Service
+          const branch = path.join(directory, ".hg", "branch")
+          yield* ready(directory)
+          expect(
+            yield* nextUpdate((event) => event.file === branch, fs.writeFileString(branch, "feature\n")),
+          ).toMatchObject({ file: branch })
+        }),
+      { vcs: "hg" },
+    ),
+  )
 })

packages/core/test/model-resolver.test.ts

@@ -21,22 +21,6 @@ interface ModelOptions {
   readonly limit?: Info["limit"]
 }
 
-const withEnv =
-  (env: Record<string, string | undefined>) =>
-  <A, E, R>(effect: Effect.Effect<A, E, R>) => {
-    const saved = Object.fromEntries(Object.keys(env).map((key) => [key, process.env[key]]))
-    const apply = (values: Record<string, string | undefined>) => {
-      for (const [key, value] of Object.entries(values)) {
-        if (value === undefined) delete process.env[key]
-        else process.env[key] = value
-      }
-    }
-    return Effect.sync(() => apply(env)).pipe(
-      Effect.andThen(effect),
-      Effect.ensuring(Effect.sync(() => apply(saved))),
-    )
-  }
-
 const model = (packageName: string | undefined, options: ModelOptions = {}) =>
   Info.make({
     id: ID.make("test-model"),
@@ -495,97 +479,6 @@ describe("ModelResolver", () => {
     }),
   )
 
-  it.effect("resolves Bedrock credentials from the AWS default chain when none are configured", () =>
-    Effect.gen(function* () {
-      const native = yield* ModelResolver.fromCatalogModel(
-        model(Provider.aisdk("@ai-sdk/openai"), {
-          settings: { baseURL: "https://openai.example/v1" },
-        }),
-      )
-      const env = {
-        AWS_ACCESS_KEY_ID: "chain-access",
-        AWS_SECRET_ACCESS_KEY: "chain-secret",
-        AWS_SESSION_TOKEN: "chain-session",
-        AWS_REGION: "eu-west-1",
-        AWS_PROFILE: undefined,
-        AWS_BEARER_TOKEN_BEDROCK: undefined,
-      }
-      yield* Effect.gen(function* () {
-        const resolved = yield* ModelResolver.fromCatalogModel(
-          model("@opencode-ai/ai/providers/amazon-bedrock", { settings: {} }),
-          undefined,
-          {
-            loadPackage: () =>
-              Effect.succeed({
-                model: (modelID, settings) => {
-                  expect(settings.credentials).toEqual({
-                    region: "eu-west-1",
-                    accessKeyId: "chain-access",
-                    secretAccessKey: "chain-secret",
-                    sessionToken: "chain-session",
-                  })
-                  expect(settings).not.toHaveProperty("apiKey")
-                  return LanguageModel.make({ id: modelID, provider: "package-provider", route: native.route })
-                },
-              }),
-          },
-        )
-        expect(resolved).toMatchObject({ id: "api-test-model", provider: "test-provider" })
-      }).pipe(withEnv(env))
-    }),
-  )
-
-  it.effect("uses the Bedrock bearer token env before the AWS default chain", () =>
-    Effect.gen(function* () {
-      const native = yield* ModelResolver.fromCatalogModel(
-        model(Provider.aisdk("@ai-sdk/openai"), {
-          settings: { baseURL: "https://openai.example/v1" },
-        }),
-      )
-      yield* Effect.gen(function* () {
-        yield* ModelResolver.fromCatalogModel(
-          model("@opencode-ai/ai/providers/amazon-bedrock", { settings: { region: "us-west-2" } }),
-          undefined,
-          {
-            loadPackage: () =>
-              Effect.succeed({
-                model: (modelID, settings) => {
-                  expect(settings.apiKey).toBe("bearer-token")
-                  expect(settings).not.toHaveProperty("credentials")
-                  return LanguageModel.make({ id: modelID, provider: "package-provider", route: native.route })
-                },
-              }),
-          },
-        )
-      }).pipe(withEnv({ AWS_BEARER_TOKEN_BEDROCK: "bearer-token" }))
-    }),
-  )
-
-  it.effect("keeps explicitly configured Bedrock credentials untouched", () =>
-    Effect.gen(function* () {
-      const native = yield* ModelResolver.fromCatalogModel(
-        model(Provider.aisdk("@ai-sdk/openai"), {
-          settings: { baseURL: "https://openai.example/v1" },
-        }),
-      )
-      const credentials = { region: "us-east-1", accessKeyId: "configured", secretAccessKey: "configured-secret" }
-      yield* ModelResolver.fromCatalogModel(
-        model("@opencode-ai/ai/providers/amazon-bedrock", { settings: { credentials } }),
-        undefined,
-        {
-          loadPackage: () =>
-            Effect.succeed({
-              model: (modelID, settings) => {
-                expect(settings.credentials).toEqual(credentials)
-                expect(settings).not.toHaveProperty("apiKey")
-                return LanguageModel.make({ id: modelID, provider: "package-provider", route: native.route })
-              },
-            }),
-        },
-      )
-    }),
-  )
-
   it.effect("maps OAuth credentials to native provider auth settings", () =>
     Effect.gen(function* () {
       const native = yield* ModelResolver.fromCatalogModel(
@@ -732,14 +625,12 @@ describe("ModelResolver", () => {
           settings: { region: "us-east-1", topP: 0.8, serviceTier: "priority" },
           body: {},
         }),
-        Credential.Key.make({ type: "key", key: "secret" }),
       )
       const mantle = yield* ModelResolver.fromCatalogModel(
         model(Provider.aisdk("@ai-sdk/amazon-bedrock/mantle"), {
           modelID: "openai.gpt-oss-120b",
           settings: { region: "us-east-1" },
         }),
-        Credential.Key.make({ type: "key", key: "secret" }),
       )
 
       expect(google.route.id).toBe("gemini")

packages/core/test/vcs-hg.test.ts

@@ -2,11 +2,14 @@ import { $ } from "bun"
 import { describe, expect } from "bun:test"
 import fs from "fs/promises"
 import path from "path"
-import { Effect, Layer } from "effect"
+import { Effect, Fiber, Layer, Stream } from "effect"
 import { LayerNode } from "@opencode-ai/util/effect/layer-node"
+import { Bus } from "@opencode-ai/core/bus"
 import { Location } from "@opencode-ai/core/location"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { Vcs } from "@opencode-ai/core/vcs"
+import { FileSystem } from "@opencode-ai/schema/filesystem"
+import { VcsEvent } from "@opencode-ai/schema/vcs-event"
 import { location } from "./fixture/location"
 import { tmpdir } from "./fixture/tmpdir"
 import { it } from "./lib/effect"
@@ -15,7 +18,7 @@ const describeHg = Bun.which("hg") ? describe : describe.skip
 
 const provide = (directory: string) =>
   Effect.provide(
-    LayerNode.compile(Vcs.node, [
+    LayerNode.compile(LayerNode.group([Vcs.node, Bus.node]), [
       [
         Location.node,
         Layer.succeed(
@@ -37,6 +40,11 @@ const withTmp = <A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) =>
     (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
   ).pipe(Effect.flatMap((tmp) => f(tmp.path)))
 
+const withHg = <A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) =>
+  withTmp((directory) =>
+    Effect.promise(() => hg(directory, "init")).pipe(Effect.andThen(f(directory).pipe(provide(directory)))),
+  )
+
 async function hg(directory: string, ...args: string[]) {
   await $`hg ${args}`.cwd(directory).env({ ...process.env, HGPLAIN: "1" }).quiet()
 }
@@ -48,10 +56,9 @@ async function commitAll(directory: string, message: string) {
 
 describeHg("Vcs mercurial", () => {
   it.live("reports modified, missing, and untracked files", () =>
-    withTmp((directory) =>
+    withHg((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await hg(directory, "init")
           await fs.writeFile(path.join(directory, "keep.txt"), "one\ntwo\n")
           await fs.writeFile(path.join(directory, "gone.txt"), "bye\n")
           await commitAll(directory, "initial")
@@ -66,15 +73,14 @@ describeHg("Vcs mercurial", () => {
           { file: "keep.txt", additions: 1, deletions: 1, status: "modified" },
           { file: "new.txt", additions: 2, deletions: 0, status: "added" },
         ])
-      }).pipe(provide(directory)),
+      }),
     ),
   )
 
   it.live("diffs the working copy with synthesized untracked and missing patches", () =>
-    withTmp((directory) =>
+    withHg((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await hg(directory, "init")
           await fs.writeFile(path.join(directory, "keep.txt"), "one\ntwo\n")
           await fs.writeFile(path.join(directory, "gone.txt"), "bye\n")
           await commitAll(directory, "initial")
@@ -96,16 +102,47 @@ describeHg("Vcs mercurial", () => {
         expect(diff[1].deletions).toBe(1)
         expect(diff[2].patch).toContain("+hello")
         expect(diff[2].additions).toBe(1)
-      }).pipe(provide(directory)),
+      }),
+    ),
+  )
+
+  it.live("caches branch info and publishes branch metadata changes", () =>
+    withHg((directory) =>
+      Effect.gen(function* () {
+        yield* Effect.promise(async () => {
+          await fs.writeFile(path.join(directory, "file.txt"), "one\n")
+          await commitAll(directory, "initial")
+        })
+        const vcs = yield* Vcs.Service
+        const bus = yield* Bus.Service
+        expect(yield* vcs.info()).toEqual({ branch: { current: "default", default: "default" } })
+
+        const updated = yield* bus.subscribe(VcsEvent.BranchUpdated).pipe(
+          Stream.take(1),
+          Stream.runHead,
+          Effect.forkScoped({ startImmediately: true }),
+        )
+        yield* Effect.promise(() => hg(directory, "branch", "-q", "feature"))
+        expect(yield* vcs.info()).toEqual({ branch: { current: "default", default: "default" } })
+
+        yield* bus.publish(FileSystem.Event.Changed, {
+          file: path.join(directory, ".hg", "branch"),
+          event: "change",
+        })
+        expect(yield* Fiber.join(updated)).toMatchObject({
+          _tag: "Some",
+          value: { location: { directory }, data: { branch: "feature" } },
+        })
+        expect(yield* vcs.info()).toEqual({ branch: { current: "feature", default: "default" } })
+      }),
     ),
   )
 
   it.live("respects the context option", () =>
-    withTmp((directory) =>
+    withHg((directory) =>
       Effect.gen(function* () {
         const body = Array.from({ length: 20 }, (_, index) => `line-${index}`).join("\n") + "\n"
         yield* Effect.promise(async () => {
-          await hg(directory, "init")
           await fs.writeFile(path.join(directory, "file.txt"), body)
           await commitAll(directory, "initial")
           await fs.writeFile(path.join(directory, "file.txt"), body.replace("line-10", "changed"))
@@ -117,15 +154,14 @@ describeHg("Vcs mercurial", () => {
         const tight = yield* vcs.diff("working", { context: 1 })
         expect(tight[0].patch).toContain("line-9")
         expect(tight[0].patch).not.toContain("line-0")
-      }).pipe(provide(directory)),
+      }),
     ),
   )
 
   it.live("diffs before the first commit", () =>
-    withTmp((directory) =>
+    withHg((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await hg(directory, "init")
           await fs.writeFile(path.join(directory, "tracked.txt"), "a\nb\n")
           await hg(directory, "add", "-q", "tracked.txt")
           await fs.writeFile(path.join(directory, "loose.txt"), "hello\n")
@@ -139,15 +175,14 @@ describeHg("Vcs mercurial", () => {
         expect(diff).toHaveLength(2)
         expect(diff[0].patch).toContain("+hello")
         expect(diff[1].patch).toContain("+a")
-      }).pipe(provide(directory)),
+      }),
     ),
   )
 
   it.live("diffs a named branch against the default branch", () =>
-    withTmp((directory) =>
+    withHg((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await hg(directory, "init")
           await fs.writeFile(path.join(directory, "file.txt"), "one\n")
           await commitAll(directory, "initial")
         })
@@ -160,12 +195,11 @@ describeHg("Vcs mercurial", () => {
           await commitAll(directory, "feature change")
         })
         const diff = yield* vcs.diff("branch")
-        expect(yield* vcs.info()).toEqual({ branch: { current: "feature", default: "default" } })
         expect(diff.map((item) => ({ file: item.file, status: item.status }))).toEqual([
           { file: "file.txt", status: "modified" },
         ])
         expect(diff[0].patch).toContain("+two")
-      }).pipe(provide(directory)),
+      }),
     ),
   )
 })

packages/core/test/vcs.test.ts

@@ -2,18 +2,21 @@ import { $ } from "bun"
 import { describe, expect } from "bun:test"
 import fs from "fs/promises"
 import path from "path"
-import { Effect, Layer } from "effect"
+import { Effect, Fiber, Layer, Stream } from "effect"
 import { LayerNode } from "@opencode-ai/util/effect/layer-node"
+import { Bus } from "@opencode-ai/core/bus"
 import { Location } from "@opencode-ai/core/location"
 import { AbsolutePath } from "@opencode-ai/core/schema"
 import { Vcs } from "@opencode-ai/core/vcs"
+import { FileSystem } from "@opencode-ai/schema/filesystem"
+import { VcsEvent } from "@opencode-ai/schema/vcs-event"
 import { location } from "./fixture/location"
 import { tmpdir } from "./fixture/tmpdir"
 import { it } from "./lib/effect"
 
 const provide = (directory: string, input: { git?: boolean } = {}) =>
   Effect.provide(
-    LayerNode.compile(Vcs.node, [
+    LayerNode.compile(LayerNode.group([Vcs.node, Bus.node]), [
       [
         Location.node,
         Layer.succeed(
@@ -35,6 +38,13 @@ const withTmp = <A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) =>
     (tmp) => Effect.promise(() => tmp[Symbol.asyncDispose]()),
   ).pipe(Effect.flatMap((tmp) => f(tmp.path)))
 
+const withGit = <A, E, R>(f: (directory: string) => Effect.Effect<A, E, R>) =>
+  withTmp((directory) =>
+    Effect.promise(() => initRepo(directory)).pipe(
+      Effect.andThen(f(directory).pipe(provide(directory, { git: true }))),
+    ),
+  )
+
 async function initRepo(directory: string) {
   await $`git init -b main`.cwd(directory).quiet()
   await $`git config core.fsmonitor false`.cwd(directory).quiet()
@@ -62,10 +72,9 @@ describe("Vcs", () => {
   )
 
   it.live("reports modified, deleted, and untracked files", () =>
-    withTmp((directory) =>
+    withGit((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await initRepo(directory)
           await fs.writeFile(path.join(directory, "keep.txt"), "one\ntwo\n")
           await fs.writeFile(path.join(directory, "gone.txt"), "bye\n")
           await commitAll(directory, "initial")
@@ -80,15 +89,45 @@ describe("Vcs", () => {
           { file: "keep.txt", additions: 1, deletions: 1, status: "modified" },
           { file: "new.txt", additions: 2, deletions: 0, status: "added" },
         ])
-      }).pipe(provide(directory, { git: true })),
+      }),
+    ),
+  )
+
+  it.live("caches branch info and publishes HEAD changes", () =>
+    withGit((directory) =>
+      Effect.gen(function* () {
+        yield* Effect.promise(async () => {
+          await fs.writeFile(path.join(directory, "file.txt"), "one\n")
+          await commitAll(directory, "initial")
+        })
+        const vcs = yield* Vcs.Service
+        const bus = yield* Bus.Service
+        expect(yield* vcs.info()).toEqual({ branch: { current: "main", default: undefined } })
+
+        const updated = yield* bus.subscribe(VcsEvent.BranchUpdated).pipe(
+          Stream.take(1),
+          Stream.runHead,
+          Effect.forkScoped({ startImmediately: true }),
+        )
+        yield* Effect.promise(() => $`git checkout -q -b feature`.cwd(directory).quiet())
+
+        yield* bus.publish(FileSystem.Event.Changed, { file: path.join(directory, "HEAD"), event: "change" })
+        expect(yield* vcs.info()).toEqual({ branch: { current: "main", default: undefined } })
+
+        yield* bus.publish(FileSystem.Event.Changed, { file: path.join(directory, ".git", "HEAD"), event: "change" })
+        expect(yield* Fiber.join(updated)).toMatchObject({
+          _tag: "Some",
+          value: { location: { directory }, data: { branch: "feature" } },
+        })
+        expect(yield* vcs.info()).toEqual({ branch: { current: "feature", default: "main" } })
+      }),
     ),
   )
 
   it.live("diffs the working copy against HEAD with patches", () =>
-    withTmp((directory) =>
+    withGit((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await initRepo(directory)
           await fs.writeFile(path.join(directory, "keep.txt"), "one\ntwo\n")
           await commitAll(directory, "initial")
           await fs.writeFile(path.join(directory, "keep.txt"), "one\nthree\n")
@@ -106,16 +145,15 @@ describe("Vcs", () => {
         expect(diff[0].deletions).toBe(1)
         expect(diff[1].patch).toContain("+hello")
         expect(diff[1].additions).toBe(1)
-      }).pipe(provide(directory, { git: true })),
+      }),
     ),
   )
 
   it.live("respects the context option", () =>
-    withTmp((directory) =>
+    withGit((directory) =>
       Effect.gen(function* () {
         const body = Array.from({ length: 20 }, (_, index) => `line-${index}`).join("\n") + "\n"
         yield* Effect.promise(async () => {
-          await initRepo(directory)
           await fs.writeFile(path.join(directory, "file.txt"), body)
           await commitAll(directory, "initial")
           await fs.writeFile(path.join(directory, "file.txt"), body.replace("line-10", "changed"))
@@ -127,15 +165,14 @@ describe("Vcs", () => {
         const tight = yield* vcs.diff("working", { context: 1 })
         expect(tight[0].patch).toContain("line-9")
         expect(tight[0].patch).not.toContain("line-0")
-      }).pipe(provide(directory, { git: true })),
+      }),
     ),
   )
 
   it.live("diffs before the first commit", () =>
-    withTmp((directory) =>
+    withGit((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await initRepo(directory)
           await fs.writeFile(path.join(directory, "new.txt"), "hello\n")
         })
         const vcs = yield* Vcs.Service
@@ -143,15 +180,14 @@ describe("Vcs", () => {
         const diff = yield* vcs.diff("working")
         expect(diff).toHaveLength(1)
         expect(diff[0].patch).toContain("+hello")
-      }).pipe(provide(directory, { git: true })),
+      }),
     ),
   )
 
   it.live("diffs a feature branch against the default branch", () =>
-    withTmp((directory) =>
+    withGit((directory) =>
       Effect.gen(function* () {
         yield* Effect.promise(async () => {
-          await initRepo(directory)
           await fs.writeFile(path.join(directory, "file.txt"), "one\n")
           await commitAll(directory, "initial")
         })
@@ -164,12 +200,11 @@ describe("Vcs", () => {
           await commitAll(directory, "feature change")
         })
         const diff = yield* vcs.diff("branch")
-        expect(yield* vcs.info()).toEqual({ branch: { current: "feature", default: "main" } })
         expect(diff.map((item) => ({ file: item.file, status: item.status }))).toEqual([
           { file: "file.txt", status: "modified" },
         ])
         expect(diff[0].patch).toContain("+two")
-      }).pipe(provide(directory, { git: true })),
+      }),
     ),
   )
 })

packages/plugin/src/tui/context.ts

@@ -19,6 +19,7 @@ import type {
   SessionPendingInfo,
   ShellInfo,
   SkillInfo,
+  VcsInfo,
 } from "@opencode-ai/client"
 import type { ResolvedTheme } from "@opencode-ai/theme/tui"
 import type { CliRenderer, KeyEvent, Renderable } from "@opentui/core"
@@ -113,6 +114,11 @@ export interface Data {
     default(): LocationRef
     sync(location?: LocationRef): Promise<void>
     invalidate(location?: LocationRef): void
+    readonly vcs: {
+      info(location?: LocationRef): VcsInfo | undefined
+      sync(location?: LocationRef): Promise<void>
+      invalidate(location?: LocationRef): void
+    }
     readonly agent: LocationCollection<AgentInfo>
     readonly command: LocationCollection<CommandInfo>
     readonly integration: LocationCollection<IntegrationInfo>

packages/tui/src/app.tsx

@@ -799,8 +799,8 @@ function App(props: { pair?: DialogPairCredentials }) {
         title: "MCP servers",
         category: "Agent",
         slash: { name: "mcps" },
-        run: () => {
-          dialog.replace(() => <DialogMcp />)
+        run: (server?: string) => {
+          dialog.replace(() => <DialogMcp server={server} />)
         },
       },
       {

packages/tui/src/component/dialog-mcp.tsx

@@ -28,7 +28,7 @@ function Status(props: { enabled: boolean; loading: boolean }) {
   return <span style={{ fg: theme.text.subdued }}>○ Disabled</span>
 }
 
-export function DialogMcp() {
+export function DialogMcp(props: { server?: string }) {
   const data = useData()
   const dialog = useDialog()
   const client = useClient()
@@ -37,6 +37,7 @@ export function DialogMcp() {
   const [focused, setFocused] = createSignal<string>()
   const [detail, setDetail] = createSignal<McpServer>()
   const [loading, setLoading] = createSignal<string | null>(null)
+  const [initial, setInitial] = createSignal(props.server)
 
   const servers = createMemo(() =>
     pipe(
@@ -45,6 +46,16 @@ export function DialogMcp() {
     ),
   )
 
+  createEffect(() => {
+    const name = initial()
+    if (!name) return
+    const server = servers().find((entry) => entry.name === name)
+    if (!server) return
+    setInitial()
+    setFocused(name)
+    if (statusError(server.status)) setDetail(server)
+  })
+
   createEffect(() => {
     if (focused()) return
     const first = servers()[0]

packages/tui/src/component/prompt/index.tsx

@@ -1329,12 +1329,17 @@ export function Prompt(props: PromptProps) {
   const locationLabel = createMemo(() => {
     if (!props.sessionID) {
       // No session yet: show where the next session will be created.
-      const directory = currentLocation.ref?.directory ?? data.location.default().directory
-      return abbreviateHome(directory, paths.home)
+      const location = currentLocation.ref ?? data.location.default()
+      const directory = abbreviateHome(location.directory, paths.home)
+      const branch = data.location.vcs.info(location)?.branch.current
+      return branch ? `${directory}:${branch}` : directory
     }
     if (status() !== "idle") return
-    const directory = data.session.get(props.sessionID)?.location.directory
-    return directory ? abbreviateHome(directory, paths.home) : undefined
+    const location = data.session.get(props.sessionID)?.location
+    if (!location) return
+    const directory = abbreviateHome(location.directory, paths.home)
+    const branch = data.location.vcs.info(location)?.branch.current
+    return branch ? `${directory}:${branch}` : directory
   })
 
   const spinnerDef = createMemo(() => {

packages/tui/src/component/session-tabs.tsx

@@ -15,7 +15,7 @@ import {
   type SessionTab,
   type SessionTabUnread,
 } from "../context/session-tabs-model"
-import { createAnimatable, spring, tween } from "../ui/animation"
+import { createAnimatable, spring } from "../ui/animation"
 import { Locale } from "../util/locale"
 import { stringWidth } from "../util/string-width"
 import { TabPulse, unreadGlowIntensity } from "./tab-pulse"
@@ -554,21 +554,6 @@ function HorizontalSessionTabs(props: { controller?: SessionTabsController; anim
           const glowColor = () => feedbackColor() ?? accent()
           const glows = () => !selected() && (status().attention || (!status().busy && status().unread !== undefined))
           const title = () => tab.title ?? "Untitled session"
-          const [outgoingTitle, setOutgoingTitle] = createSignal<string>()
-          const wipe = createAnimatable({ front: 1 }, { enabled: animations, transition: tween({ duration: 0.3 }) })
-          createEffect((previous: string) => {
-            const next = title()
-            if (next === previous) return next
-            if (previous === NEW_SESSION_TAB_TITLE) {
-              setOutgoingTitle(undefined)
-              wipe.jump({ front: 1 })
-              return next
-            }
-            setOutgoingTitle(previous)
-            wipe.jump({ front: 0 })
-            wipe.animate({ front: 1 })
-            return next
-          }, title())
           const tabNumber = createMemo(() => items().findIndex((item) => item.sessionID === tab.sessionID) + 1)
           // The number cell keeps one trailing space, even for double-digit tabs.
           const numberWidth = () => String(tabNumber()).length + 1
@@ -577,20 +562,6 @@ function HorizontalSessionTabs(props: { controller?: SessionTabsController; anim
             Math.max(1, width() - 1 - numberWidth() - (hovered() === tab.sessionID ? 2 : 0))
           const visibleTitle = createMemo(() => Locale.takeWidth(title(), availableTitleWidth()))
           const visibleTitleParts = createMemo(() => Locale.graphemes(visibleTitle()))
-          const outgoingTitleParts = createMemo(() => {
-            const outgoing = outgoingTitle()
-            if (outgoing === undefined) return undefined
-            return Locale.graphemes(Locale.takeWidth(outgoing, availableTitleWidth()))
-          })
-          // A new title wipes in from the left over the previous one.
-          const displayedParts = createMemo(() => {
-            const front = wipe.value().front
-            const parts = visibleTitleParts()
-            const previous = outgoingTitleParts()
-            if (previous === undefined || front >= 1) return parts
-            const cut = Math.round(front * Math.max(parts.length, previous.length))
-            return [...parts.slice(0, cut), ...previous.slice(cut)]
-          })
           const titleFades = createMemo(
             () => stringWidth(title()) >= availableTitleWidth() && availableTitleWidth() > FADE_WIDTH,
           )
@@ -603,8 +574,8 @@ function HorizontalSessionTabs(props: { controller?: SessionTabsController; anim
           const characterColor = (index: number) => {
             const base = foreground()
             const color = glows() ? glowTextColor(base, glowColor(), 1 + numberWidth() + index, width()) : base
-            if (!titleFades() || index < displayedParts().length - FADE_WIDTH) return color
-            const position = index - (displayedParts().length - FADE_WIDTH)
+            if (!titleFades() || index < visibleTitleParts().length - FADE_WIDTH) return color
+            const position = index - (visibleTitleParts().length - FADE_WIDTH)
             return tint(color, background(), 0.2 + 0.72 * (position / Math.max(1, FADE_WIDTH - 1)))
           }
           // The running sweep's level under the number cell, reported by the pulse renderable.
@@ -677,8 +648,8 @@ function HorizontalSessionTabs(props: { controller?: SessionTabsController; anim
                   selectable={false}
                   attributes={bold()}
                 >
-                  <Show when={glows() || titleFades()} fallback={displayedParts().join("")}>
-                    <For each={displayedParts()}>
+                  <Show when={glows() || titleFades()} fallback={visibleTitle()}>
+                    <For each={visibleTitleParts()}>
                       {(character, index) => <span style={{ fg: characterColor(index()) }}>{character}</span>}
                     </For>
                   </Show>

packages/tui/src/context/data.tsx

@@ -27,6 +27,7 @@ import type {
   SessionPendingInfo,
   ShellInfo,
   SkillInfo,
+  VcsInfo,
   OpenCodeEvent,
   WebSearchProvider,
 } from "@opencode-ai/client"
@@ -49,6 +50,7 @@ type ShellWithLocation = ShellInfo & { readonly location: LocationRef }
 
 type LocationData = {
   info?: LocationGetOutput
+  vcs?: VcsInfo
   agent?: AgentInfo[]
   command?: CommandInfo[]
   integration?: IntegrationInfo[]
@@ -339,6 +341,17 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
           result.location.skill.invalidate(event.location)
           void result.location.skill.sync(event.location)
           break
+        case "vcs.branch.updated":
+          setStore("location", locationKey(event.location ?? defaultLocation()), (data) => ({
+            ...data,
+            vcs: {
+              branch: {
+                ...data?.vcs?.branch,
+                current: event.data.branch,
+              },
+            },
+          }))
+          break
         case "session.agent.selected":
           if (store.session.info[event.data.sessionID])
             setStore("session", "info", event.data.sessionID, "agent", event.data.agent)
@@ -1152,6 +1165,7 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
           })
           const location = ref ?? defaultLocation()
           await Promise.all([
+            result.location.vcs.sync(location),
             result.location.agent.sync(location),
             result.location.command.sync(location),
             result.location.integration.sync(location),
@@ -1168,6 +1182,7 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
         invalidate(ref?: LocationRef) {
           const location = ref ?? defaultLocation()
           sync.invalidate(`location:${locationKey(location)}`)
+          result.location.vcs.invalidate(location)
           result.location.agent.invalidate(location)
           result.location.command.invalidate(location)
           result.location.integration.invalidate(location)
@@ -1180,6 +1195,22 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
           result.shell.invalidate(location)
           result.session.form.invalidate("global", location)
         },
+        vcs: {
+          info(location?: LocationRef) {
+            return store.location[locationKey(location ?? defaultLocation())]?.vcs
+          },
+          sync(ref?: LocationRef) {
+            const location = ref ?? defaultLocation()
+            return sync.run(`location.vcs:${locationKey(location)}`, async () => {
+              const response = await client.api.vcs.get({ location: locationQuery(location) })
+              const key = locationKey(response.location)
+              setStore("location", key, { ...store.location[key], vcs: response.data })
+            })
+          },
+          invalidate(ref?: LocationRef) {
+            sync.invalidate(`location.vcs:${locationKey(ref ?? defaultLocation())}`)
+          },
+        },
         agent: {
           list(location?: LocationRef) {
             return store.location[locationKey(location ?? defaultLocation())]?.agent
@@ -1377,6 +1408,7 @@ export const { use: useData, provider: DataProvider } = createSimpleContext({
               setStore("location", key, { ...store.location[key], info: location })
             })
             .catch((error) => console.error("Failed to preload location", error))
+          void result.location.vcs.sync().catch((error) => console.error("Failed to preload VCS info", error))
           void result.project.sync().catch((error) => console.error("Failed to preload projects", error))
           return
         }

packages/tui/src/feature-plugins/sidebar/footer.tsx

@@ -3,9 +3,12 @@ import { createMemo, Show } from "solid-js"
 import { FilePath } from "../../ui/file-path"
 
 function View(props: { context: Plugin.Context }) {
-  const directory = createMemo(() =>
-    props.context.location ? props.context.ui.format.path(props.context.location.directory) : undefined,
-  )
+  const directory = createMemo(() => {
+    if (!props.context.location) return undefined
+    const value = props.context.ui.format.path(props.context.location.directory)
+    const branch = props.context.data.location.vcs.info(props.context.location)?.branch.current
+    return branch ? `${value}:${branch}` : value
+  })
   return (
     <Show when={directory()}>
       {(value) => <FilePath value={value()} maxWidth={38} fg={props.context.theme.text.subdued} />}

packages/tui/src/feature-plugins/sidebar/mcp.tsx

@@ -1,7 +1,7 @@
 import { Plugin } from "@opencode-ai/plugin/tui"
 import { createMemo, For, Match, Show, Switch, createSignal } from "solid-js"
 
-function View(props: { context: Plugin.Context; sessionID: string }) {
+export function McpSidebar(props: { context: Plugin.Context; sessionID: string }) {
   const [open, setOpen] = createSignal(true)
   const theme = props.context.theme
   const session = createMemo(() => props.context.data.session.get(props.sessionID))
@@ -46,7 +46,14 @@ function View(props: { context: Plugin.Context; sessionID: string }) {
         <Show when={list().length <= 2 || open()}>
           <For each={list()}>
             {(item) => (
-              <box flexDirection="row" gap={1}>
+              <box
+                flexDirection="row"
+                gap={1}
+                onMouseUp={() => {
+                  if (item.status.status !== "failed" && item.status.status !== "needs_client_registration") return
+                  props.context.keymap.dispatch("mcp.list", item.name)
+                }}
+              >
                 <text
                   flexShrink={0}
                   style={{
@@ -60,9 +67,7 @@ function View(props: { context: Plugin.Context; sessionID: string }) {
                   <span style={{ fg: theme.text.subdued }}>
                     <Switch fallback={item.status.status}>
                       <Match when={item.status.status === "connected"}>Connected</Match>
-                      <Match when={item.status.status === "failed"}>
-                        <i>{item.status.status === "failed" ? item.status.error : undefined}</i>
-                      </Match>
+                      <Match when={item.status.status === "failed"}>Failed</Match>
                       <Match when={item.status.status === "disabled"}>Disabled</Match>
                       <Match when={item.status.status === "needs_auth"}>Needs auth</Match>
                       <Match when={item.status.status === "needs_client_registration"}>Needs client ID</Match>
@@ -81,6 +86,6 @@ function View(props: { context: Plugin.Context; sessionID: string }) {
 export default Plugin.define({
   id: "internal:sidebar-mcp",
   setup(context) {
-    context.ui.slot("sidebar.content", (props) => <View context={context} sessionID={props.sessionID} />)
+    context.ui.slot("sidebar.content", (props) => <McpSidebar context={context} sessionID={props.sessionID} />)
   },
 })

packages/tui/test/cli/tui/data.test.tsx

@@ -106,6 +106,49 @@ test("does not preload session summaries into the data context", async () => {
   }
 })
 
+test("syncs VCS info and applies branch updates", async () => {
+  const events = createEventStream()
+  const calls = createFetch((url) => {
+    if (url.pathname !== "/api/vcs") return undefined
+    return json({
+      location: { directory, project: { id: "proj_test", directory: worktree, canonical: worktree } },
+      data: { branch: { current: "main", default: "main" } },
+    })
+  }, events)
+  let data!: ReturnType<typeof useData>
+
+  function Probe() {
+    data = useData()
+    return <box />
+  }
+
+  const app = await testRender(() => (
+    <TestTuiContexts>
+      <ClientProvider api={createApi(calls.fetch)}>
+        <ProjectProvider>
+          <DataProvider>
+            <Probe />
+          </DataProvider>
+        </ProjectProvider>
+      </ClientProvider>
+    </TestTuiContexts>
+  ))
+
+  try {
+    await wait(() => data.location.vcs.info()?.branch.current === "main")
+    emitEvent(events, {
+      id: "evt_vcs_branch",
+      created: Date.now(),
+      type: "vcs.branch.updated",
+      data: { branch: "feature" },
+    })
+    await wait(() => data.location.vcs.info()?.branch.current === "feature")
+    expect(data.location.vcs.info()?.branch).toEqual({ current: "feature", default: "main" })
+  } finally {
+    app.renderer.destroy()
+  }
+})
+
 test("proactively syncs project metadata newest first", async () => {
   const events = createEventStream()
   const calls = createFetch((url) => {

packages/tui/test/feature-plugins/sidebar-mcp.test.tsx

@@ -0,0 +1,51 @@
+/** @jsxImportSource @opentui/solid */
+import { expect, test } from "bun:test"
+import { RGBA } from "@opentui/core"
+import { testRender } from "@opentui/solid"
+import type { Context } from "@opencode-ai/plugin/tui/context"
+import { McpSidebar } from "../../src/feature-plugins/sidebar/mcp"
+
+function context() {
+  const color = RGBA.fromInts(200, 200, 200)
+  return {
+    theme: {
+      text: {
+        default: color,
+        subdued: color,
+        feedback: { success: { default: color }, error: { default: color }, warning: { default: color } },
+      },
+    },
+    data: {
+      session: { get: () => ({ location: { directory: "/workspace" } }) },
+      location: {
+        mcp: {
+          server: {
+            list: () => [
+              {
+                name: "broken",
+                status: { status: "failed", error: "<!DOCTYPE html><html><body>raw response</body></html>" },
+              },
+            ],
+          },
+        },
+      },
+    },
+  } as unknown as Context
+}
+
+test("sidebar summarizes MCP failures without rendering error details", async () => {
+  const app = await testRender(() => <McpSidebar context={context()} sessionID="session" />, {
+    width: 42,
+    height: 8,
+  })
+
+  try {
+    await app.renderOnce()
+    const frame = app.captureCharFrame()
+    expect(frame).toContain("broken Failed")
+    expect(frame).not.toContain("DOCTYPE")
+    expect(frame).not.toContain("raw response")
+  } finally {
+    app.renderer.destroy()
+  }
+})

packages/tui/test/fixture/tui-client.ts

@@ -95,6 +95,11 @@ export function createFetch(override?: FetchHandler, events?: ReturnType<typeof
     if (url.pathname === "/path") return json({ home: "", state: "", config: "", worktree, directory })
     if (url.pathname === "/api/location")
       return json({ directory, project: { id: "proj_test", directory: worktree, canonical: worktree } })
+    if (url.pathname === "/api/vcs")
+      return json({
+        location: { directory, project: { id: "proj_test", directory: worktree, canonical: worktree } },
+        data: { branch: { current: "main", default: "main" } },
+      })
     if (url.pathname === "/api/fs/list")
       return json({ location: { directory, project: { id: "proj_test", directory: worktree, canonical: worktree } }, data: [] })
     if (url.pathname === "/api/project/current") return json({ id: "proj_test", directory: worktree })