diff --git a/packages/opencode/package.json b/packages/opencode/package.json
index 419f8ffa4b..b1eebd0f99 100644
--- a/packages/opencode/package.json
+++ b/packages/opencode/package.json
@@ -134,6 +134,7 @@
     "opencode-poe-auth": "0.0.1",
     "opentui-spinner": "catalog:",
     "partial-json": "0.1.7",
+    "playwright-core": "1.62.1",
     "remeda": "catalog:",
     "semver": "^7.6.3",
     "solid-js": "catalog:",
diff --git a/packages/opencode/src/guard/index.ts b/packages/opencode/src/guard/index.ts
index 1e151ca4cc..974221f4c3 100644
--- a/packages/opencode/src/guard/index.ts
+++ b/packages/opencode/src/guard/index.ts
@@ -45,14 +45,28 @@ function hostOf(url: string): string {
   }
 }
 
-export function installGuard() {
+export function egressCheck(url: string) {
   const mode = process.env.NEURON_GUARD ?? "log"
   const strict = mode === "strict"
   const allow = (process.env.NEURON_GUARD_ALLOW ?? "")
     .split(",")
     .map((h) => h.trim())
     .filter(Boolean)
+  const host = hostOf(url)
+  const entry: Entry = { t: new Date().toISOString(), host, url }
+  if (strict && !allow.includes(host)) {
+    for (const denied of DENYLIST) {
+      if (host === denied || host.endsWith("." + denied) || url.includes(denied)) {
+        entry.blocked = true
+        log(entry)
+        throw new Error(`Neuron guard: egress to ${denied} is blocked (NEURON_GUARD=strict)`)
+      }
+    }
+  }
+  log(entry)
+}
 
+export function installGuard() {
   const original = globalThis.fetch
   const guarded = async (input: RequestInfo | URL, init?: RequestInit) => {
     const url =
@@ -61,18 +75,7 @@ export function installGuard() {
         : input instanceof URL
           ? input.href
           : (input && "url" in input && typeof input.url === "string" ? input.url : String(input))
-    const host = hostOf(url)
-    const entry: Entry = { t: new Date().toISOString(), host, url }
-    if (strict && !allow.includes(host)) {
-      for (const denied of DENYLIST) {
-        if (host === denied || host.endsWith("." + denied) || url.includes(denied)) {
-          entry.blocked = true
-          log(entry)
-          throw new Error(`Neuron guard: egress to ${denied} is blocked (NEURON_GUARD=strict)`)
-        }
-      }
-    }
-    log(entry)
+    egressCheck(url)
     return original(input, init)
   }
   // preserve fetch-adjacent properties attached by the runtime
diff --git a/packages/opencode/src/tool/browser.ts b/packages/opencode/src/tool/browser.ts
new file mode 100644
index 0000000000..f693aa2cdc
--- /dev/null
+++ b/packages/opencode/src/tool/browser.ts
@@ -0,0 +1,132 @@
+import { Effect, Schema } from "effect"
+import { chromium, type Browser, type Page } from "playwright-core"
+import * as Tool from "./tool"
+import { egressCheck } from "@/guard"
+import DESCRIPTION from "./browser.txt"
+
+const MAX_CONTENT = 20_000
+
+const Parameters = Schema.Struct({
+  action: Schema.Literals(["navigate", "click", "fill", "content", "screenshot", "close"]).annotate({
+    description: "Browser operation to perform",
+  }),
+  url: Schema.optional(Schema.String).annotate({ description: "Absolute URL for navigate" }),
+  selector: Schema.optional(Schema.String).annotate({ description: "CSS selector for click/fill" }),
+  text: Schema.optional(Schema.String).annotate({ description: "Text to type for fill" }),
+  path: Schema.optional(Schema.String).annotate({ description: "Absolute PNG path for screenshot" }),
+  all: Schema.optional(Schema.Boolean).annotate({
+    description: "For close: true closes the whole browser, false (default) closes only the active tab",
+    default: false,
+  }),
+})
+
+let browserPromise: Promise<Browser> | undefined
+let active: Page | undefined
+
+const getBrowser = () =>
+  Effect.promise(async () => {
+    if (!browserPromise) {
+      browserPromise = chromium.launch({ channel: "chrome", headless: true })
+    }
+    return browserPromise
+  })
+
+const getPage = () =>
+  Effect.gen(function* () {
+    const browser = yield* getBrowser()
+    if (!active || active.isClosed()) {
+      active = yield* Effect.promise(() => browser.newPage())
+    }
+    return active
+  })
+
+const visibleText = (page: Page) =>
+  Effect.tryPromise({
+    try: async () => {
+      const text = await page.evaluate(() => document.body?.innerText ?? "")
+      const title = await page.title()
+      const trimmed = text.length > MAX_CONTENT ? `${text.slice(0, MAX_CONTENT)}\n...[truncated]` : text
+      return `# ${title}\n\n${trimmed}`
+    },
+    catch: (error) => new Error(error instanceof Error ? error.message : String(error)),
+  }).pipe(Effect.orDie)
+
+export const BrowserTool = Tool.define(
+  "browser",
+  Effect.gen(function* () {
+    return {
+      description: DESCRIPTION,
+      parameters: Parameters,
+      execute: (params: Schema.Schema.Type<typeof Parameters>, _ctx: Tool.Context) =>
+        Effect.gen(function* () {
+          switch (params.action) {
+            case "navigate": {
+              if (!params.url) throw new Error("url is required for navigate")
+              if (!params.url.startsWith("http://") && !params.url.startsWith("https://"))
+                throw new Error("URL must start with http:// or https://")
+              egressCheck(params.url)
+              const page = yield* getPage()
+              yield* Effect.tryPromise({
+                try: () => page.goto(params.url!, { waitUntil: "domcontentloaded", timeout: 45_000 }),
+                catch: (error) => new Error(error instanceof Error ? error.message : String(error)),
+              }).pipe(Effect.orDie)
+              const body = yield* visibleText(page)
+              return { title: `navigate ${params.url}`, metadata: {}, output: body }
+            }
+
+            case "click": {
+              if (!params.selector) throw new Error("selector is required for click")
+              const page = yield* getPage()
+              yield* Effect.tryPromise({
+                try: () => page.click(params.selector!, { timeout: 10_000 }),
+                catch: (error) => new Error(error instanceof Error ? error.message : String(error)),
+              }).pipe(Effect.orDie)
+              yield* Effect.promise(() => page.waitForLoadState("domcontentloaded").catch(() => undefined))
+              return { title: `click ${params.selector}`, metadata: {}, output: "clicked" }
+            }
+
+            case "fill": {
+              if (!params.selector || params.text === undefined) throw new Error("selector and text are required for fill")
+              const page = yield* getPage()
+              yield* Effect.tryPromise({
+                try: () => page.fill(params.selector!, params.text!, { timeout: 10_000 }),
+                catch: (error) => new Error(error instanceof Error ? error.message : String(error)),
+              }).pipe(Effect.orDie)
+              return { title: `fill ${params.selector}`, metadata: {}, output: "filled" }
+            }
+
+            case "content": {
+              const page = yield* getPage()
+              const body = yield* visibleText(page)
+              return { title: `content ${page.url()}`, metadata: {}, output: body }
+            }
+
+            case "screenshot": {
+              if (!params.path) throw new Error("path is required for screenshot")
+              const page = yield* getPage()
+              yield* Effect.tryPromise({
+                try: () => page.screenshot({ path: params.path!, fullPage: false }),
+                catch: (error) => new Error(error instanceof Error ? error.message : String(error)),
+              }).pipe(Effect.orDie)
+              return { title: `screenshot ${params.path}`, metadata: {}, output: `saved to ${params.path}` }
+            }
+
+            case "close": {
+              if (!active) return { title: "close", metadata: {}, output: "no active page" }
+              const page = active
+              if (params.all) {
+                const browser = yield* getBrowser()
+                yield* Effect.promise(() => browser.close())
+                browserPromise = undefined
+                active = undefined
+                return { title: "close", metadata: {}, output: "browser closed" }
+              }
+              yield* Effect.promise(() => page.close())
+              active = undefined
+              return { title: "close", metadata: {}, output: "tab closed" }
+            }
+          }
+        }),
+    }
+  }),
+)
diff --git a/packages/opencode/src/tool/browser.txt b/packages/opencode/src/tool/browser.txt
new file mode 100644
index 0000000000..e2d9aed6d7
--- /dev/null
+++ b/packages/opencode/src/tool/browser.txt
@@ -0,0 +1,19 @@
+Drive a real headless Chrome browser.
+
+One browser instance is shared across calls in this session; pages persist
+between calls, so you can navigate once and then click, fill, and read on
+subsequent calls. Every navigation passes through the Neuron egress guard —
+in NEURON_GUARD=strict mode, denylisted hosts are refused.
+
+Actions:
+
+- `navigate` (url): open a URL in a new tab and make it active. Returns the
+  page title and readable text.
+- `click` (selector): click an element by CSS selector.
+- `fill` (selector, text): clear and type text into an input/textarea.
+- `content`: return the active page's visible text (truncated).
+- `screenshot` (path): save a PNG of the active page to an absolute path.
+- `close`: close the active tab (or the whole browser with `all: true`).
+
+Selectors are plain CSS (`#id`, `.class`, `a[href*="docs"]`). Prefer reading
+`content` before clicking blind — know the page before you act on it.