diff --git a/packages/plugin-browser/src/files.ts b/packages/plugin-browser/src/files.ts
index ea2729e4054..c7c8cb8578d 100644
--- a/packages/plugin-browser/src/files.ts
+++ b/packages/plugin-browser/src/files.ts
@@ -5,7 +5,7 @@ import { Browser } from "@opencode-ai/schema/browser"
 // Files cross machines as bytes. Only this endpoint interprets its local paths.
 export async function read(paths: readonly string[], directory: string): Promise<Browser.File[]> {
   const { open } = await import("node:fs/promises")
-  const { resolve, basename } = await import("node:path")
+  const { resolve, basename, extname } = await import("node:path")
   const files = await Promise.all(
     paths.map(async (input) => {
       const file = await open(resolve(directory, input), "r")
@@ -13,13 +13,11 @@ export async function read(paths: readonly string[], directory: string): Promise
         const stat = await file.stat()
         if (!stat.isFile() || stat.size > Browser.MAX_FILE_BYTES)
           throw new Error("Upload must be a file no larger than 5 MiB.")
-        const data = new Uint8Array(Number(stat.size))
-        const { bytesRead } = await file.read(data, 0, data.length, 0)
         return {
           id: Browser.FileID.make(`file_${crypto.randomUUID()}`),
           name: basename(input),
-          mime: "application/octet-stream",
-          data: data.subarray(0, bytesRead),
+          mime: types[extname(input).toLowerCase()] ?? "application/octet-stream",
+          data: new Uint8Array(await file.readFile()),
         }
       } finally {
         await file.close()
@@ -31,6 +29,22 @@ export async function read(paths: readonly string[], directory: string): Promise
   return files
 }
 
+const types: Record<string, string> = {
+  ".txt": "text/plain",
+  ".csv": "text/csv",
+  ".json": "application/json",
+  ".html": "text/html",
+  ".png": "image/png",
+  ".jpg": "image/jpeg",
+  ".jpeg": "image/jpeg",
+  ".webp": "image/webp",
+  ".gif": "image/gif",
+  ".svg": "image/svg+xml",
+  ".pdf": "application/pdf",
+  ".zip": "application/zip",
+  ".gz": "application/gzip",
+}
+
 export async function save(files: readonly Browser.File[]): Promise<Browser.FileInfo[]> {
   if (files.length === 0) return []
   if (files.reduce((size, file) => size + file.data.byteLength, 0) > Browser.MAX_FILE_BYTES)
diff --git a/packages/plugin-browser/src/index.ts b/packages/plugin-browser/src/index.ts
index a64e8bcf402..1dcd9ff991e 100644
--- a/packages/plugin-browser/src/index.ts
+++ b/packages/plugin-browser/src/index.ts
@@ -58,7 +58,7 @@ export default Plugin.define({
                 (browser) => (browsers.get(input.sessionID) === browser ? close(input.sessionID) : Effect.void),
               )
               yield* rpc.events
-                .emit("control", { type: "attached", connectionID: input.connectionID })
+                .emit("control", { type: "attached", connectionID: input.connectionID, version: 2 })
                 .pipe(Effect.orDie)
               yield* Deferred.await(browser.closed)
             }).pipe(Effect.scoped),
@@ -95,8 +95,16 @@ export default Plugin.define({
         })
         .pipe(Effect.orDie)
 
-      const execute = (operation: Browser.Operation, action: Browser.Action, tool: Tool.Context) =>
+      const execute = (operation: Browser.Operation, input: Browser.Action, tool: Tool.Context) =>
         Effect.gen(function* () {
+          const action = yield* Effect.try({
+            try: () => normalizeAction(input),
+            catch: (error) =>
+              new Tool.Error({
+                message: "Invalid browser URL. Use HTTP, HTTPS, or about:blank without credentials.",
+                error,
+              }),
+          })
           const browser = browsers.get(tool.sessionID)
           if (!browser)
             return yield* new Tool.Error({ message: "[browser.disconnected] No desktop browser is connected." })
@@ -225,3 +233,16 @@ function requireObject(value: unknown): Record<string, unknown> {
     throw new Error("Browser file output must be an object.")
   return value as Record<string, unknown>
 }
+
+function normalizeAction(action: Browser.Action): Browser.Action {
+  if (action.type !== "navigate" && action.type !== "tabs.open") return action
+  if (action.type === "tabs.open" && action.url === undefined) return action
+  const value = action.url?.trim() || "about:blank"
+  const local = /^(?:localhost|127(?:\.\d{1,3}){3}|\[::1\])(?::\d+)?(?:[/?#]|$)/i.test(value)
+  const url = new URL(
+    value === "about:blank" || /^[a-z][a-z\d+.-]*:\/\//i.test(value) ? value : `${local ? "http" : "https"}://${value}`,
+  )
+  if ((url.href !== "about:blank" && !/^https?:$/.test(url.protocol)) || url.username || url.password)
+    throw new Error("Unsupported browser URL")
+  return { ...action, url: url.href }
+}
diff --git a/packages/schema/src/browser.ts b/packages/schema/src/browser.ts
index faf0da2562c..c387cc649b5 100644
--- a/packages/schema/src/browser.ts
+++ b/packages/schema/src/browser.ts
@@ -16,13 +16,19 @@ const limit = optional(Schema.Int.check(Schema.isBetween({ minimum: 1, maximum:
 const timeoutMs = optional(Schema.Int.check(Schema.isBetween({ minimum: 1, maximum: 30_000 }))).annotate({
   description: "Timeout in milliseconds, 1–30000. Default 10000.",
 })
-export const TabID = Schema.String.check(Schema.isPattern(/^tab_[a-f0-9-]{36}$/)).pipe(Schema.brand("Browser.TabID"))
+export const TabID = Schema.String.check(Schema.isPattern(/^tab_[a-f0-9-]{36}$/))
+  .pipe(Schema.brand("Browser.TabID"))
+  .annotate({ identifier: "Browser.TabID" })
 export type TabID = typeof TabID.Type
-export const Ref = Schema.String.check(Schema.isPattern(/^@?e[1-9][0-9]*$/)).pipe(Schema.brand("Browser.Ref"))
+export const Ref = Schema.String.check(Schema.isPattern(/^@?e[1-9][0-9]*$/))
+  .pipe(Schema.brand("Browser.Ref"))
+  .annotate({ identifier: "Browser.Ref" })
 export type Ref = typeof Ref.Type
-export const FileID = Schema.String.check(Schema.isPattern(/^file_[a-f0-9-]{36}$/)).pipe(Schema.brand("Browser.FileID"))
+export const FileID = Schema.String.check(Schema.isPattern(/^file_[a-f0-9-]{36}$/))
+  .pipe(Schema.brand("Browser.FileID"))
+  .annotate({ identifier: "Browser.FileID" })
 export type FileID = typeof FileID.Type
-export const tab = {
+const tab = {
   tabID: TabID.annotate({
     description: "Exact tab ID returned by browser.tabs.open/list. Focus does not select a tool target.",
   }),
@@ -87,7 +93,7 @@ export const ResourceType = Schema.Literals([
   "websocket",
   "manifest",
   "other",
-])
+]).annotate({ identifier: "Browser.ResourceType" })
 export type ResourceType = typeof ResourceType.Type
 const headers = Schema.Array(Schema.Struct({ name: short, value: text }))
 export const Body = Schema.Union([
@@ -99,17 +105,19 @@ export const Body = Schema.Union([
   }),
 ]).annotate({ identifier: "Browser.Body" })
 export type Body = typeof Body.Type
-export const NetworkRequest = Schema.Struct({
+const requestFields = {
   id: short,
   url: text,
   method: short,
   resourceType: ResourceType,
   timestampMs: Schema.Finite,
-  state: Schema.Literals(["pending", "completed", "failed"]),
   statusCode: optional(count),
-  durationMs: optional(Schema.Finite),
-  failure: optional(short),
-}).annotate({ identifier: "Browser.NetworkRequest" })
+}
+export const NetworkRequest = Schema.Union([
+  Schema.Struct({ ...requestFields, state: Schema.Literal("pending") }),
+  Schema.Struct({ ...requestFields, state: Schema.Literal("completed"), durationMs: Schema.Finite }),
+  Schema.Struct({ ...requestFields, state: Schema.Literal("failed"), durationMs: Schema.Finite, failure: short }),
+]).annotate({ identifier: "Browser.NetworkRequest" })
 export type NetworkRequest = typeof NetworkRequest.Type
 export const ConsoleEntry = Schema.Struct({
   id: short,
@@ -489,7 +497,7 @@ const attachment = { sessionID: Session.ID, connectionID: Schema.String }
 const request = { ...attachment, requestID: Schema.String }
 const errors = { unavailable: Schema.Struct({}) }
 export const Control = Schema.Union([
-  Schema.Struct({ type: Schema.Literal("attached"), connectionID: Schema.String }),
+  Schema.Struct({ type: Schema.Literal("attached"), connectionID: Schema.String, version: Schema.Literal(2) }),
   Schema.Struct({
     type: Schema.Literal("command"),
     connectionID: Schema.String,
diff --git a/packages/schema/test/browser.test.ts b/packages/schema/test/browser.test.ts
index a7d2af8a3a5..89c9a98608e 100644
--- a/packages/schema/test/browser.test.ts
+++ b/packages/schema/test/browser.test.ts
@@ -39,3 +39,11 @@ test("browser files are bounded bytes, not remote filesystem paths", () => {
     }),
   ).toThrow()
 })
+
+test("network lifecycle and RPC version are explicit", () => {
+  const request = { id: "request", url: "https://example.com", method: "GET", resourceType: "document", timestampMs: 1 }
+  const decode = Schema.decodeUnknownSync(Browser.NetworkRequest)
+  expect(decode({ ...request, state: "completed", statusCode: 404, durationMs: 3 }).state).toBe("completed")
+  expect(() => decode({ ...request, state: "failed" })).toThrow()
+  expect(() => Schema.decodeUnknownSync(Browser.Control)({ type: "attached", connectionID: "old-client" })).toThrow()
+})
diff --git a/packages/sdk/test/browser-plugin.test.ts b/packages/sdk/test/browser-plugin.test.ts
index 998c2dc02d7..292ee0730db 100644
--- a/packages/sdk/test/browser-plugin.test.ts
+++ b/packages/sdk/test/browser-plugin.test.ts
@@ -95,7 +95,7 @@ const fixture = Effect.gen(function* () {
     attach: Effect.fn(function* (connectionID: string) {
       const input = { sessionID: session.id, connectionID }
       const lifetime = yield* rpc.attach({ ...input, version: 2 }, { location }).pipe(Effect.forkScoped)
-      expect((yield* next).data).toEqual({ type: "attached", connectionID })
+      expect((yield* next).data).toEqual({ type: "attached", connectionID, version: 2 })
       return { input, lifetime }
     }),
     command: Effect.fn(function* (action: Browser.Action) {