perf(tui): tighten markdown demo rendering

package.json

@@ -7,6 +7,8 @@
   "packageManager": "bun@1.3.13",
   "scripts": {
     "dev": "bun run --cwd packages/opencode --conditions=browser src/index.ts",
+    "dev:demo": "bun run --cwd packages/opencode --conditions=browser src/index.ts --demo",
+    "dev:run-demo": "bun run --cwd packages/opencode --conditions=browser src/index.ts run --interactive --demo",
     "dev:desktop": "bun --cwd packages/desktop dev",
     "dev:web": "bun --cwd packages/app dev",
     "dev:console": "ulimit -n 10240 2>/dev/null; bun run --cwd packages/console/app dev",

packages/opencode/package.json

@@ -13,6 +13,8 @@
     "build": "bun run script/build.ts",
     "fix-node-pty": "bun run script/fix-node-pty.ts",
     "dev": "bun run --conditions=browser ./src/index.ts",
+    "dev:demo": "bun run --conditions=browser ./src/index.ts --demo",
+    "dev:run-demo": "bun run --conditions=browser ./src/index.ts run --interactive --demo",
     "dev:temporary": "bun run --conditions=browser ./src/temporary.ts",
     "db": "bun drizzle-kit"
   },

packages/opencode/src/cli/cmd/demo-fixtures.ts

@@ -0,0 +1,181 @@
+export const SAMPLE_MARKDOWN = [
+  "# Direct Mode Demo",
+  "",
+  "This is a realistic assistant response for direct-mode formatting checks.",
+  "It mixes **bold**, _italic_, `inline code`, links, code fences, and tables in one streamed reply.",
+  "",
+  "## Summary",
+  "",
+  "- Restored the final markdown flush so the last block is committed on idle.",
+  "- Switched markdown scrollback commits back to top-level block boundaries.",
+  "- Added footer-level regression coverage for split-footer rendering.",
+  "",
+  "## Status",
+  "",
+  "| Area | Before | After | Notes |",
+  "| --- | --- | --- | --- |",
+  "| Direct mode | Missing final rows | Stable | Final markdown block now flushes on idle |",
+  "| Tables | Dropped in streaming mode | Visible | Block-based commits match the working OpenTUI demo |",
+  "| Tests | Partial coverage | Broader coverage | Includes a footer-level split render capture |",
+  "",
+  "> This sample intentionally includes a wide table so you can spot wrapping and commit bugs quickly.",
+  "",
+  "```ts",
+  "const result = { markdown: true, tables: 2, stable: true }",
+  "```",
+  "",
+  "## Files",
+  "",
+  "| File | Change |",
+  "| --- | --- |",
+  "| `scrollback.surface.ts` | Align markdown commit logic with the split-footer demo |",
+  "| `footer.ts` | Keep active surfaces across footer-height-only resizes |",
+  "| `footer.test.ts` | Capture real split-footer markdown payloads during idle completion |",
+  "",
+  "Next step: run `/fmt table` if you want a tighter table-only sample.",
+].join("\n")
+
+export const SAMPLE_TABLE = [
+  "# Table Sample",
+  "",
+  "| Kind | Example | Notes |",
+  "| --- | --- | --- |",
+  "| Pipe | `A\\|B` | Escaped pipes should stay in one cell |",
+  "| Unicode | `漢字` | Wide characters should remain aligned |",
+  "| Wrap | `LongTokenWithoutNaturalBreaks_1234567890` | Useful for width stress |",
+  "| Status | done | Final row should still appear after idle |",
+].join("\n")
+
+export const MARKDOWN_PATTERNS = {
+  "md-code": [
+    "# Interleaved Code",
+    "",
+    "Start with a short conclusion before any code appears.",
+    "",
+    "```ts",
+    "export function parse(input: string) {",
+    "  return input.trim().split(/\\s+/)",
+    "}",
+    "```",
+    "",
+    "Then continue with prose immediately after the code block. This should not inherit code styling or indentation.",
+    "",
+    "```tsx",
+    "<Show when={props.enabled}>",
+    "  <markdown content={props.text} streaming />",
+    "</Show>",
+    "```",
+    "",
+    "Final paragraph after a second fence with `inline code`, **bold text**, and _emphasis_ mixed together.",
+  ].join("\n"),
+  "md-fence": [
+    "# Fence Boundaries",
+    "",
+    "The renderer should recover cleanly around multiple fences and nearby paragraphs.",
+    "",
+    "```bash",
+    "bun run test -- --grep markdown",
+    "```",
+    "Text directly after a fence.",
+    "```json",
+    "{",
+    '  "status": "ok",',
+    '  "items": ["one", "two"]',
+    "}",
+    "```",
+    "Trailing paragraph after JSON. The next fence intentionally has no language.",
+    "```",
+    "plain fenced text",
+    "with multiple lines",
+    "```",
+  ].join("\n"),
+  "md-list": [
+    "# Lists With Code",
+    "",
+    "1. First ordered item with `inline code`.",
+    "2. Second ordered item before a nested list:",
+    "   - Nested bullet with a long phrase that should wrap without swallowing the marker or changing indentation.",
+    "   - Nested bullet before fenced code:",
+    "",
+    "     ```ts",
+    "     const nested = true",
+    "     ```",
+    "",
+    "3. Third ordered item after the nested fence.",
+    "",
+    "- Top-level bullet after ordered list.",
+    "- Another bullet with a paragraph below.",
+    "",
+    "  Continuation paragraph should stay associated with the bullet without becoming code.",
+  ].join("\n"),
+  "md-table-code": [
+    "# Tables And Code",
+    "",
+    "| Case | Input | Expected |",
+    "| --- | --- | --- |",
+    "| Inline code | `const x = 1` | stays inline |",
+    "| Escaped pipe | `A\\|B` | one cell |",
+    "| Long token | `LongTokenWithoutNaturalBreaks_1234567890_abcdefghijklmnopqrstuvwxyz` | wraps or scrolls predictably |",
+    "",
+    "A code block follows the table:",
+    "",
+    "```ts",
+    "const rows = [",
+    '  { case: "inline code", expected: "stays inline" },',
+    '  { case: "escaped pipe", expected: "one cell" },',
+    "]",
+    "```",
+    "",
+    "And then another compact table:",
+    "",
+    "| A | B |",
+    "| - | - |",
+    "| done | yes |",
+  ].join("\n"),
+  "md-inline": [
+    "# Inline Markdown",
+    "",
+    "This paragraph mixes [a normal link](https://opencode.ai), `https://example.com/code-link`, `inline code`, **strong**, _emphasis_, and ~~strikethrough~~.",
+    "",
+    "> Blockquote with `inline code` and [a link](https://example.com) should keep quote styling while wrapping.",
+    "",
+    "A horizontal rule follows.",
+    "",
+    "---",
+    "",
+    "After the rule, text should resume normal spacing.",
+  ].join("\n"),
+  "md-kitchen": [
+    "# Markdown Kitchen Sink",
+    "",
+    "This combines headings, paragraphs, lists, blockquotes, tables, inline code, and multiple code fences.",
+    "",
+    "## Steps",
+    "",
+    "1. Read the response.",
+    "2. Notice `inline code` before a block.",
+    "",
+    "```ts",
+    "type Result = { ok: boolean; reason?: string }",
+    "const result: Result = { ok: true }",
+    "```",
+    "",
+    "3. Continue the list after the block.",
+    "",
+    "> Quoted note after the list. It should not merge into the previous item.",
+    "",
+    "| Feature | Stress |",
+    "| --- | --- |",
+    "| Markdown | prose/code/table interleave |",
+    "| Renderer | wrapping and spacing |",
+    "",
+    "```diff",
+    "- const renderer = oldMarkdown",
+    "+ const renderer = experimentalMarkdown",
+    "```",
+    "",
+    "Final paragraph with [docs](https://opencode.ai/docs) and `https://example.com/from-code`.",
+  ].join("\n"),
+} as const
+
+export const MARKDOWN_PATTERN_KINDS = Object.keys(MARKDOWN_PATTERNS) as Array<keyof typeof MARKDOWN_PATTERNS>

packages/opencode/src/cli/cmd/run/demo.ts

@@ -19,9 +19,11 @@ import type { Event, ToolPart } from "@opencode-ai/sdk/v2"
 import { createSessionData, reduceSessionData, type SessionData } from "./session-data"
 import { writeSessionOutput } from "./stream"
 import type { FooterApi, PermissionReply, QuestionReject, QuestionReply, RunPrompt, StreamCommit } from "./types"
+import { MARKDOWN_PATTERN_KINDS, MARKDOWN_PATTERNS, SAMPLE_MARKDOWN, SAMPLE_TABLE } from "../demo-fixtures"
 
 const KINDS = [
   "markdown",
+  ...MARKDOWN_PATTERN_KINDS,
   "table",
   "text",
   "reasoning",
@@ -51,53 +53,9 @@ function questionKind(value: string | undefined): QuestionKind | undefined {
   return QUESTIONS.find((item) => item === next)
 }
 
-const SAMPLE_MARKDOWN = [
-  "# Direct Mode Demo",
-  "",
-  "This is a realistic assistant response for direct-mode formatting checks.",
-  "It mixes **bold**, _italic_, `inline code`, links, code fences, and tables in one streamed reply.",
-  "",
-  "## Summary",
-  "",
-  "- Restored the final markdown flush so the last block is committed on idle.",
-  "- Switched markdown scrollback commits back to top-level block boundaries.",
-  "- Added footer-level regression coverage for split-footer rendering.",
-  "",
-  "## Status",
-  "",
-  "| Area | Before | After | Notes |",
-  "| --- | --- | --- | --- |",
-  "| Direct mode | Missing final rows | Stable | Final markdown block now flushes on idle |",
-  "| Tables | Dropped in streaming mode | Visible | Block-based commits match the working OpenTUI demo |",
-  "| Tests | Partial coverage | Broader coverage | Includes a footer-level split render capture |",
-  "",
-  "> This sample intentionally includes a wide table so you can spot wrapping and commit bugs quickly.",
-  "",
-  "```ts",
-  "const result = { markdown: true, tables: 2, stable: true }",
-  "```",
-  "",
-  "## Files",
-  "",
-  "| File | Change |",
-  "| --- | --- |",
-  "| `scrollback.surface.ts` | Align markdown commit logic with the split-footer demo |",
-  "| `footer.ts` | Keep active surfaces across footer-height-only resizes |",
-  "| `footer.test.ts` | Capture real split-footer markdown payloads during idle completion |",
-  "",
-  "Next step: run `/fmt table` if you want a tighter table-only sample.",
-].join("\n")
-
-const SAMPLE_TABLE = [
-  "# Table Sample",
-  "",
-  "| Kind | Example | Notes |",
-  "| --- | --- | --- |",
-  "| Pipe | `A\\|B` | Escaped pipes should stay in one cell |",
-  "| Unicode | `漢字` | Wide characters should remain aligned |",
-  "| Wrap | `LongTokenWithoutNaturalBreaks_1234567890` | Useful for width stress |",
-  "| Status | done | Final row should still appear after idle |",
-].join("\n")
+function markdownPattern(value: string): keyof typeof MARKDOWN_PATTERNS | undefined {
+  if (value in MARKDOWN_PATTERNS) return value as keyof typeof MARKDOWN_PATTERNS
+}
 
 type Ref = {
   msg: string
@@ -1031,6 +989,12 @@ async function emitFmt(state: State, kind: string, body: string, signal?: AbortS
     return true
   }
 
+  const pattern = markdownPattern(kind)
+  if (pattern) {
+    await emitText(state, body || MARKDOWN_PATTERNS[pattern], signal)
+    return true
+  }
+
   if (kind === "table") {
     await emitText(state, body || SAMPLE_TABLE, signal)
     return true

packages/opencode/src/cli/cmd/run/runtime.ts

@@ -14,7 +14,7 @@
 //   4. runs the prompt queue until the footer closes.
 import { createOpencodeClient } from "@opencode-ai/sdk/v2"
 import { Flag } from "@opencode-ai/core/flag/flag"
-import { createRunDemo } from "./demo"
+import type { createRunDemo } from "./demo"
 import { resolveDiffStyle, resolveFooterKeybinds, resolveModelInfo, resolveSessionInfo } from "./runtime.boot"
 import { createRuntimeLifecycle } from "./runtime.lifecycle"
 import { recordRunSpanError, setRunSpanAttributes, withRunSpan } from "./otel"
@@ -135,6 +135,10 @@ function variantsFor(providers: RunProvider[], model: RunInput["model"]) {
   return Object.keys(providers.find((item) => item.id === model.providerID)?.models?.[model.modelID]?.variants ?? {})
 }
 
+async function createDemo(input: Parameters<typeof createRunDemo>[0]) {
+  return (await import("./demo")).createRunDemo(input)
+}
+
 async function resolveExitTitle(
   ctx: BootContext,
   input: RunRuntimeInput,
@@ -425,7 +429,7 @@ async function runInteractiveRuntime(input: RunRuntimeInput): Promise<void> {
 
       if (input.demo) {
         await ensureSession()
-        state.demo = createRunDemo({
+        state.demo = await createDemo({
           footer,
           sessionID: state.sessionID,
           thinking: input.thinking,
@@ -548,7 +552,7 @@ async function runInteractiveRuntime(input: RunRuntimeInput): Promise<void> {
                   state.history = []
                   includeFiles = true
                   state.demo = input.demo
-                    ? createRunDemo({
+                    ? await createDemo({
                         footer,
                         sessionID: state.sessionID,
                         thinking: input.thinking,

packages/opencode/src/cli/cmd/tui/context/theme.tsx

@@ -962,6 +962,8 @@ function getSyntaxRules(theme: Theme) {
       style: {
         foreground: theme.markdownHeading,
         bold: true,
+        italic: true,
+        underline: true,
       },
     },
     {
@@ -1175,6 +1177,7 @@ function getSyntaxRules(theme: Theme) {
       scope: ["markup.strikethrough"],
       style: {
         foreground: theme.textMuted,
+        strikethrough: true,
       },
     },
     {

packages/opencode/src/cli/cmd/tui/demo.ts

@@ -0,0 +1,285 @@
+import type {
+  Agent,
+  AssistantMessage,
+  Config,
+  Message,
+  Model,
+  Part,
+  Path,
+  Project,
+  Provider,
+  Session,
+} from "@opencode-ai/sdk/v2"
+import type { EventSource } from "./context/sdk"
+import { MARKDOWN_PATTERNS, SAMPLE_MARKDOWN, SAMPLE_TABLE } from "../demo-fixtures"
+
+const sessionID = "demo_tui_markdown"
+const userMessageID = "demo_tui_user"
+const assistantMessageID = "demo_tui_assistant"
+const now = Date.now()
+
+const markdown = [
+  "# Fullscreen TUI Markdown Demo",
+  "",
+  "This fake assistant response runs through the fullscreen session timeline without calling an LLM.",
+  "Use it to compare spacing, wrapping, code fence boundaries, table behavior, and inline markdown rendering.",
+  "",
+  "## Baseline",
+  "",
+  SAMPLE_MARKDOWN,
+  "",
+  "## Table Baseline",
+  "",
+  SAMPLE_TABLE,
+  "",
+  ...Object.entries(MARKDOWN_PATTERNS).flatMap(([name, value]) => ["## " + name, "", value, ""]),
+].join("\n")
+
+const model = {
+  id: "demo",
+  providerID: "demo",
+  api: {
+    id: "demo",
+    url: "https://example.com/demo",
+    npm: "demo",
+  },
+  name: "Demo",
+  capabilities: {
+    temperature: false,
+    reasoning: true,
+    attachment: false,
+    toolcall: true,
+    input: {
+      text: true,
+      audio: false,
+      image: false,
+      video: false,
+      pdf: false,
+    },
+    output: {
+      text: true,
+      audio: false,
+      image: false,
+      video: false,
+      pdf: false,
+    },
+    interleaved: true,
+  },
+  cost: {
+    input: 0,
+    output: 0,
+    cache: {
+      read: 0,
+      write: 0,
+    },
+  },
+  limit: {
+    context: 128_000,
+    output: 16_000,
+  },
+  status: "active",
+  options: {},
+  headers: {},
+  release_date: "2026-01-01",
+} satisfies Model
+
+const provider = {
+  id: "demo",
+  name: "Demo",
+  source: "custom",
+  env: [],
+  options: {},
+  models: {
+    demo: model,
+  },
+} satisfies Provider
+
+const agent = {
+  name: "build",
+  description: "Demo agent",
+  mode: "primary",
+  native: true,
+  permission: [],
+  model: {
+    providerID: "demo",
+    modelID: "demo",
+  },
+  options: {},
+} satisfies Agent
+
+function json(data: unknown, status = 200) {
+  return new Response(JSON.stringify(data), {
+    status,
+    headers: {
+      "content-type": "application/json",
+    },
+  })
+}
+
+export function createTuiDemo(input: { directory: string }) {
+  const paths = {
+    home: process.env.HOME ?? input.directory,
+    state: input.directory,
+    config: input.directory,
+    worktree: input.directory,
+    directory: input.directory,
+  } satisfies Path
+
+  const project = {
+    id: "demo_project",
+    worktree: input.directory,
+    vcs: "git",
+    name: "Markdown Demo",
+    time: {
+      created: now,
+      updated: now,
+    },
+    sandboxes: [],
+  } satisfies Project
+
+  const session = {
+    id: sessionID,
+    slug: "markdown-demo",
+    projectID: project.id,
+    directory: input.directory,
+    title: "Markdown Rendering Demo",
+    agent: agent.name,
+    model: {
+      id: model.id,
+      providerID: provider.id,
+    },
+    version: "demo",
+    time: {
+      created: now,
+      updated: now + 2,
+    },
+  } satisfies Session
+
+  const user = {
+    id: userMessageID,
+    sessionID,
+    role: "user",
+    time: {
+      created: now,
+    },
+    agent: agent.name,
+    model: {
+      providerID: provider.id,
+      modelID: model.id,
+    },
+  } satisfies Message
+
+  const assistant = {
+    id: assistantMessageID,
+    sessionID,
+    role: "assistant",
+    time: {
+      created: now + 1,
+      completed: now + 2,
+    },
+    parentID: userMessageID,
+    modelID: model.id,
+    providerID: provider.id,
+    mode: "demo",
+    agent: agent.name,
+    path: {
+      cwd: input.directory,
+      root: input.directory,
+    },
+    cost: 0,
+    tokens: {
+      input: 120,
+      output: 3_200,
+      reasoning: 0,
+      cache: {
+        read: 0,
+        write: 0,
+      },
+    },
+  } satisfies AssistantMessage
+
+  const messages = [
+    {
+      info: user,
+      parts: [
+        {
+          id: "demo_tui_user_text",
+          sessionID,
+          messageID: userMessageID,
+          type: "text",
+          text: "Show me the fullscreen TUI markdown rendering stress cases.",
+          time: {
+            start: now,
+            end: now,
+          },
+        },
+      ],
+    },
+    {
+      info: assistant,
+      parts: [
+        {
+          id: "demo_tui_assistant_text",
+          sessionID,
+          messageID: assistantMessageID,
+          type: "text",
+          text: markdown,
+          time: {
+            start: now + 1,
+            end: now + 2,
+          },
+        },
+      ],
+    },
+  ] satisfies Array<{ info: Message; parts: Part[] }>
+
+  const fetch = (async (...args: Parameters<typeof globalThis.fetch>) => {
+    const request = new Request(args[0], args[1])
+    const url = new URL(request.url)
+    const pathname = url.pathname
+
+    if (request.method === "GET" && pathname === "/path") return json(paths)
+    if (request.method === "GET" && pathname === "/project/current") return json(project)
+    if (request.method === "GET" && pathname === "/config/providers") {
+      return json({ providers: [provider], default: { build: "demo/demo" } })
+    }
+    if (request.method === "GET" && pathname === "/provider") {
+      return json({ all: [provider], default: { build: "demo/demo" }, connected: [provider.id] })
+    }
+    if (request.method === "GET" && pathname === "/experimental/console") {
+      return json({ consoleManagedProviders: [], switchableOrgCount: 0 })
+    }
+    if (request.method === "GET" && pathname === "/agent") return json([agent])
+    if (request.method === "GET" && pathname === "/config") {
+      return json({ model: "demo/demo", default_agent: agent.name } satisfies Config)
+    }
+    if (request.method === "GET" && pathname === "/session") return json([session])
+    if (request.method === "GET" && pathname === "/command") return json([])
+    if (request.method === "GET" && pathname === "/lsp") return json([])
+    if (request.method === "GET" && pathname === "/mcp") return json({})
+    if (request.method === "GET" && pathname === "/experimental/resource") return json({})
+    if (request.method === "GET" && pathname === "/formatter") return json([])
+    if (request.method === "GET" && pathname === "/session/status") return json({ [sessionID]: { type: "idle" } })
+    if (request.method === "GET" && pathname === "/provider/auth") return json({})
+    if (request.method === "GET" && pathname === "/vcs") return json({ branch: "demo", default_branch: "dev" })
+    if (request.method === "GET" && pathname === "/experimental/workspace") return json([])
+    if (request.method === "GET" && pathname === "/experimental/workspace/status") return json([])
+    if (request.method === "GET" && pathname === `/session/${sessionID}`) return json(session)
+    if (request.method === "GET" && pathname === `/session/${sessionID}/message`) return json(messages)
+    if (request.method === "GET" && pathname === `/session/${sessionID}/todo`) return json([])
+    if (request.method === "GET" && pathname === `/session/${sessionID}/diff`) return json([])
+    if (request.method === "GET" && pathname === `/session/${sessionID}/children`) return json([])
+
+    return json({ message: `Unhandled demo endpoint: ${request.method} ${pathname}` }, 404)
+  }) as typeof globalThis.fetch
+
+  const events = {
+    subscribe: async () => () => {},
+  } satisfies EventSource
+
+  return {
+    sessionID,
+    fetch,
+    events,
+  }
+}

packages/opencode/src/cli/cmd/tui/routes/session/index.tsx

@@ -21,7 +21,20 @@ import { useEvent } from "@tui/context/event"
 import { SplitBorder } from "@tui/component/border"
 import { Spinner } from "@tui/component/spinner"
 import { selectedForeground, useTheme } from "@tui/context/theme"
-import { BoxRenderable, ScrollBoxRenderable, addDefaultParsers, TextAttributes, RGBA } from "@opentui/core"
+import {
+  BoxRenderable,
+  ScrollBoxRenderable,
+  addDefaultParsers,
+  TextAttributes,
+  RGBA,
+  type MarkdownOptions,
+  type MarkdownRenderable,
+  CodeRenderable,
+  TextTableRenderable,
+  TextRenderable,
+  StyledText,
+  type TextChunk,
+} from "@opentui/core"
 import { Prompt, type PromptRef } from "@tui/component/prompt"
 import type {
   AssistantMessage,
@@ -1525,15 +1538,180 @@ function ReasoningPart(props: { last: boolean; part: ReasoningPart; message: Ass
 function TextPart(props: { last: boolean; part: TextPart; message: AssistantMessage }) {
   const ctx = use()
   const { theme, syntax } = useTheme()
+  const text = createMemo(() => props.part.text.trim())
+  const diffCache = new Map<string, TextChunk[]>()
+  const colorDiffChunks = (text: string) => {
+    const key = `${theme.diffAdded.toString()}:${theme.diffRemoved.toString()}:${text}`
+    const cached = diffCache.get(key)
+    if (cached) return cached
+
+    let line: "added" | "removed" | undefined
+    let start = true
+    const chunks = (text.match(/[^\n]+|\n/g) ?? [text]).map((part): TextChunk => {
+      if (start && part !== "\n") {
+        line = part.startsWith("+") ? "added" : part.startsWith("-") ? "removed" : undefined
+        start = false
+      }
+      const next = {
+        __isChunk: true,
+        text: part,
+        ...(line === "added" ? { fg: theme.diffAdded } : {}),
+        ...(line === "removed" ? { fg: theme.diffRemoved } : {}),
+      } satisfies TextChunk
+      if (part === "\n") {
+        line = undefined
+        start = true
+      }
+      return next
+    })
+    diffCache.set(key, chunks)
+    if (diffCache.size > 20) diffCache.delete(diffCache.keys().next().value!)
+    return chunks
+  }
+  const renderBlockquoteBar = (chunks: TextChunk[]) => {
+    let lineStart = true
+    let spaces = 0
+    let replaced = false
+    let skipWhitespace = false
+    return chunks.flatMap((chunk) => {
+      const result: TextChunk[] = []
+      let next = ""
+      const flush = () => {
+        if (!next) return
+        result.push(next === chunk.text ? chunk : { ...chunk, text: next })
+        next = ""
+      }
+      for (const char of chunk.text) {
+        if (skipWhitespace && (char === " " || char === "\t")) {
+          skipWhitespace = false
+          continue
+        }
+        skipWhitespace = false
+        if (lineStart && !replaced && char === " " && spaces < 3) {
+          spaces++
+          next += char
+          continue
+        }
+        if (lineStart && !replaced && char === ">") {
+          flush()
+          result.push({ __isChunk: true, text: "│ ", fg: theme.textMuted, attributes: TextAttributes.NONE })
+          replaced = true
+          skipWhitespace = true
+          continue
+        }
+        next += char
+        if (char === "\n") {
+          lineStart = true
+          spaces = 0
+          replaced = false
+          skipWhitespace = false
+          continue
+        }
+        lineStart = false
+      }
+      flush()
+      return result
+    })
+  }
+  const trimCodeIndent = (value: string) => {
+    const lines = value.split("\n")
+    const indents = lines.filter((line) => line.trim()).map((line) => line.match(/^[ \t]*/)?.[0].length ?? 0)
+    const indent = Math.min(...indents)
+    if (!Number.isFinite(indent) || indent === 0) return value
+    return lines.map((line) => (line.trim() ? line.slice(indent) : line)).join("\n")
+  }
+  const padTableCells = (renderable: TextTableRenderable) => {
+    renderable.content = renderable.content.map((row) =>
+      row.map((cell) => {
+        const content = cell ?? []
+        return [{ __isChunk: true, text: " " }, ...content, { __isChunk: true, text: " " }] satisfies TextChunk[]
+      }),
+    )
+  }
+  const configureMarkdown = (node: MarkdownRenderable | undefined) => {
+    if (!node) return
+    const renderNode: NonNullable<MarkdownOptions["renderNode"]> = (token, context) => {
+      const content = text()
+      const firstBlock = content.startsWith(token.raw.trimStart())
+
+      if (token.type === "hr") {
+        return new BoxRenderable(node.ctx, {
+          width: "100%",
+          height: 1,
+          border: ["top"],
+          borderColor: theme.border,
+          flexShrink: 0,
+        })
+      }
+
+      if (token.type === "blockquote") {
+        const renderable = context.defaultRender()
+        if (renderable instanceof CodeRenderable) {
+          const code = renderable
+          const onChunks = code.onChunks
+          code.onChunks = (chunks, context) => {
+            const result = onChunks?.call(code, chunks, context)
+            if (result instanceof Promise) return result.then((next) => renderBlockquoteBar(next ?? chunks))
+            return renderBlockquoteBar(result ?? chunks)
+          }
+        }
+        if (!firstBlock && renderable) {
+          renderable.marginTop = typeof renderable.marginTop === "number" ? Math.max(renderable.marginTop, 1) : 1
+        }
+        return renderable
+      }
+
+      const needsCodeTopGap = token.type === "code" && !firstBlock
+      if (token.type === "code" && /^[ \t]{4,}(```|~~~)/.test(token.raw)) {
+        token.text = trimCodeIndent(token.text)
+      }
+
+      if (token.type === "table") {
+        const renderable = context.defaultRender()
+        if (renderable instanceof TextTableRenderable) padTableCells(renderable)
+        return renderable
+      }
+
+      if (token.type === "code" && token.lang?.trim().toLowerCase() === "diff") {
+        const renderable = new TextRenderable(node.ctx, {
+          content: new StyledText(colorDiffChunks(token.text)),
+          width: "100%",
+          flexShrink: 0,
+        })
+        if (needsCodeTopGap) renderable.marginTop = 1
+        return renderable
+      }
+
+      const renderable = context.defaultRender()
+      if (token.type === "heading" && token.depth === 1 && !firstBlock && renderable) {
+        renderable.marginTop = typeof renderable.marginTop === "number" ? Math.max(renderable.marginTop, 2) : 2
+      }
+      if (needsCodeTopGap && renderable) {
+        renderable.marginTop = typeof renderable.marginTop === "number" ? Math.max(renderable.marginTop, 1) : 1
+      }
+      return renderable
+    }
+
+    // OpenTUI Solid constructs elements with only `{ id }`, so constructor-only
+    // MarkdownOptions need to be installed on the renderable directly.
+    const target = node as unknown as {
+      _internalBlockMode: "top-level"
+      _renderNode: typeof renderNode
+    }
+    target._internalBlockMode = "top-level"
+    target._renderNode = renderNode
+  }
   return (
-    <Show when={props.part.text.trim()}>
+    <Show when={text()}>
       <box id={"text-" + props.part.id} paddingLeft={3} marginTop={1} flexShrink={0}>
         <Switch>
           <Match when={Flag.OPENCODE_EXPERIMENTAL_MARKDOWN}>
             <markdown
               syntaxStyle={syntax()}
               streaming={true}
-              content={props.part.text.trim()}
+              ref={configureMarkdown}
+              tableOptions={{ style: "grid", widthMode: "content" }}
+              content={text()}
               conceal={ctx.conceal()}
               fg={theme.markdownText}
               bg={theme.background}
@@ -1545,7 +1723,7 @@ function TextPart(props: { last: boolean; part: TextPart; message: AssistantMess
               drawUnstyledText={false}
               streaming={true}
               syntaxStyle={syntax()}
-              content={props.part.text.trim()}
+              content={text()}
               conceal={ctx.conceal()}
               fg={theme.text}
             />

packages/opencode/src/cli/cmd/tui/thread.ts

@@ -111,6 +111,10 @@ export const TuiThreadCommand = cmd({
       .option("agent", {
         type: "string",
         describe: "agent to use",
+      })
+      .option("demo", {
+        type: "boolean",
+        describe: "open a fake fullscreen TUI session for renderer debugging",
       }),
   handler: async (args) => {
     // Keep ENABLE_PROCESSED_INPUT cleared even if other code flips it.
@@ -130,7 +134,6 @@ export const TuiThreadCommand = cmd({
       // Resolve relative --project paths from PWD, then use the real cwd after
       // chdir so the thread and worker share the same directory key.
       const next = resolveThreadDirectory(args.project)
-      const file = await target()
       try {
         process.chdir(next)
       } catch {
@@ -138,6 +141,32 @@ export const TuiThreadCommand = cmd({
         return
       }
       const cwd = Filesystem.resolve(process.cwd())
+      const config = TuiConfig.get()
+      config.catch(() => {})
+
+      if (args.demo) {
+        const { createTuiDemo } = await import("./demo")
+        const { tui } = await import("./app")
+        const demo = createTuiDemo({ directory: cwd })
+        await tui({
+          url: "http://opencode.demo",
+          config: await config,
+          directory: cwd,
+          fetch: demo.fetch,
+          events: demo.events,
+          args: {
+            continue: false,
+            sessionID: demo.sessionID,
+            agent: args.agent,
+            model: args.model,
+            prompt: await input(args.prompt),
+            fork: false,
+          },
+        })
+        return
+      }
+
+      const file = await target()
       const env = sanitizedProcessEnv({
         [OPENCODE_PROCESS_ROLE]: "worker",
         [OPENCODE_RUN_ID]: ensureRunID(),
@@ -187,8 +216,6 @@ export const TuiThreadCommand = cmd({
       }
 
       const prompt = await input(args.prompt)
-      const config = await TuiConfig.get()
-
       const network = resolveNetworkOptionsNoConfig(args)
       const external =
         process.argv.includes("--port") ||
@@ -236,7 +263,7 @@ export const TuiThreadCommand = cmd({
             const server = await client.call("snapshot", undefined)
             return [tui, server]
           },
-          config,
+          config: await config,
           directory: cwd,
           fetch: transport.fetch,
           events: transport.events,

packages/opencode/src/effect/app-runtime.ts

@@ -30,6 +30,7 @@ import { SessionProcessor } from "@/session/processor"
 import { SessionCompaction } from "@/session/compaction"
 import { SessionRevert } from "@/session/revert"
 import { SessionSummary } from "@/session/summary"
+import { SessionTimeline } from "@/session/timeline"
 import { SessionPrompt } from "@/session/prompt"
 import { Instruction } from "@/session/instruction"
 import { LLM } from "@/session/llm"
@@ -85,6 +86,7 @@ export const AppLayer = Layer.mergeAll(
   SessionCompaction.defaultLayer,
   SessionRevert.defaultLayer,
   SessionSummary.defaultLayer,
+  SessionTimeline.defaultLayer,
   SessionPrompt.defaultLayer,
   Instruction.defaultLayer,
   LLM.defaultLayer,

packages/opencode/src/server/routes/instance/httpapi/server.ts

@@ -41,6 +41,7 @@ import { SessionRevert } from "@/session/revert"
 import { SessionRunState } from "@/session/run-state"
 import { SessionStatus } from "@/session/status"
 import { SessionSummary } from "@/session/summary"
+import { SessionTimeline } from "@/session/timeline"
 import { Todo } from "@/session/todo"
 import { SessionShare } from "@/share/session"
 import { ShareNext } from "@/share/share-next"
@@ -210,6 +211,7 @@ export function createRoutes(corsOptions?: CorsOptions) {
       SessionRunState.defaultLayer,
       SessionStatus.defaultLayer,
       SessionSummary.defaultLayer,
+      SessionTimeline.defaultLayer,
       ShareNext.defaultLayer,
       Snapshot.defaultLayer,
       SyncEvent.defaultLayer,

packages/opencode/src/session/prompt.ts

@@ -4,7 +4,7 @@ import * as EffectZod from "@opencode-ai/core/effect-zod"
 import { SessionID, MessageID, PartID } from "./schema"
 import { MessageV2 } from "./message-v2"
 import * as Log from "@opencode-ai/core/util/log"
-import { SessionRevert } from "./revert"
+import { SessionTimeline } from "./timeline"
 import * as Session from "./session"
 import { Agent } from "../agent/agent"
 import { Provider } from "@/provider/provider"
@@ -114,7 +114,7 @@ export const layer = Layer.effect(
     const scope = yield* Scope.Scope
     const instruction = yield* Instruction.Service
     const state = yield* SessionRunState.Service
-    const revert = yield* SessionRevert.Service
+    const timeline = yield* SessionTimeline.Service
     const summary = yield* SessionSummary.Service
     const sys = yield* SystemPrompt.Service
     const llm = yield* LLM.Service
@@ -747,9 +747,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
           const { msg, part, cwd } = yield* Effect.gen(function* () {
             const ctx = yield* InstanceState.context
             const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
-            if (session.revert) {
-              yield* revert.cleanup(session)
-            }
+            if (session.revert) yield* timeline.commitPending({ sessionID: session.id })
             const agent = yield* agents.get(input.agent)
             if (!agent) {
               const available = (yield* agents.list()).filter((a) => !a.hidden).map((a) => a.name)
@@ -1378,7 +1376,7 @@ NOTE: At any point in time through this workflow you should feel free to ask the
       "SessionPrompt.prompt",
     )(function* (input: PromptInput) {
       const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
-      yield* revert.cleanup(session)
+      yield* timeline.commitPending({ sessionID: session.id })
       const message = yield* createUserMessage(input)
       yield* sessions.touch(input.sessionID)
 
@@ -1792,7 +1790,7 @@ export const defaultLayer = Layer.suspend(() =>
     Layer.provide(AppFileSystem.defaultLayer),
     Layer.provide(Plugin.defaultLayer),
     Layer.provide(Session.defaultLayer),
-    Layer.provide(SessionRevert.defaultLayer),
+    Layer.provide(SessionTimeline.defaultLayer),
     Layer.provide(SessionSummary.defaultLayer),
     Layer.provide(Image.defaultLayer),
     Layer.provide(

packages/opencode/src/session/revert.ts

@@ -1,16 +1,10 @@
 import { Effect, Layer, Context, Schema } from "effect"
-import { Bus } from "../bus"
-import { Snapshot } from "../snapshot"
-import { Storage } from "@/storage/storage"
-import { SyncEvent } from "../sync"
 import * as Log from "@opencode-ai/core/util/log"
 import { zod } from "@opencode-ai/core/effect-zod"
 import { withStatics } from "@opencode-ai/core/schema"
 import * as Session from "./session"
-import { MessageV2 } from "./message-v2"
-import { SessionID, MessageID, PartID } from "./schema"
-import { SessionRunState } from "./run-state"
-import { SessionSummary } from "./summary"
+import { SessionID, MessageID, PartID, RewindFilePolicy } from "./schema"
+import { SessionTimeline } from "./timeline"
 
 const log = Log.create({ service: "session.revert" })
 
@@ -18,6 +12,7 @@ export const RevertInput = Schema.Struct({
   sessionID: SessionID,
   messageID: MessageID,
   partID: Schema.optional(PartID),
+  files: Schema.optional(RewindFilePolicy),
 }).pipe(withStatics((s) => ({ zod: zod(s) })))
 export type RevertInput = Schema.Schema.Type<typeof RevertInput>
 
@@ -32,133 +27,25 @@ export class Service extends Context.Service<Service, Interface>()("@opencode/Se
 export const layer = Layer.effect(
   Service,
   Effect.gen(function* () {
-    const sessions = yield* Session.Service
-    const snap = yield* Snapshot.Service
-    const storage = yield* Storage.Service
-    const bus = yield* Bus.Service
-    const summary = yield* SessionSummary.Service
-    const state = yield* SessionRunState.Service
-    const sync = yield* SyncEvent.Service
+    const timeline = yield* SessionTimeline.Service
 
     const revert = Effect.fn("SessionRevert.revert")(function* (input: RevertInput) {
-      yield* state.assertNotBusy(input.sessionID)
-      const all = yield* sessions.messages({ sessionID: input.sessionID })
-      let lastUser: MessageV2.User | undefined
-      const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
-
-      let rev: Session.Info["revert"]
-      const patches: Snapshot.Patch[] = []
-      for (const msg of all) {
-        if (msg.info.role === "user") lastUser = msg.info
-        const remaining = []
-        for (const part of msg.parts) {
-          if (rev) {
-            if (part.type === "patch") patches.push(part)
-            continue
-          }
-
-          if (!rev) {
-            if ((msg.info.id === input.messageID && !input.partID) || part.id === input.partID) {
-              const partID = remaining.some((item) => ["text", "tool"].includes(item.type)) ? input.partID : undefined
-              rev = {
-                messageID: !partID && lastUser ? lastUser.id : msg.info.id,
-                partID,
-              }
-            }
-            remaining.push(part)
-          }
-        }
-      }
-
-      if (!rev) return session
-
-      rev.snapshot = session.revert?.snapshot ?? (yield* snap.track())
-      if (session.revert?.snapshot) yield* snap.restore(session.revert.snapshot)
-      yield* snap.revert(patches)
-      if (rev.snapshot) rev.diff = yield* snap.diff(rev.snapshot)
-      const range = all.filter((msg) => msg.info.id >= rev.messageID)
-      const diffs = yield* summary.computeDiff({ messages: range })
-      yield* storage.write(["session_diff", input.sessionID], diffs).pipe(Effect.ignore)
-      yield* bus.publish(Session.Event.Diff, { sessionID: input.sessionID, diff: diffs })
-      yield* sessions.setRevert({
-        sessionID: input.sessionID,
-        revert: rev,
-        summary: {
-          additions: diffs.reduce((sum, x) => sum + x.additions, 0),
-          deletions: diffs.reduce((sum, x) => sum + x.deletions, 0),
-          files: diffs.length,
-        },
-      })
-      return yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+      return yield* timeline.rewind(input)
     })
 
     const unrevert = Effect.fn("SessionRevert.unrevert")(function* (input: { sessionID: SessionID }) {
       log.info("unreverting", input)
-      yield* state.assertNotBusy(input.sessionID)
-      const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
-      if (!session.revert) return session
-      if (session.revert.snapshot) yield* snap.restore(session.revert.snapshot)
-      yield* sessions.clearRevert(input.sessionID)
-      return yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+      return yield* timeline.restore(input)
     })
 
     const cleanup = Effect.fn("SessionRevert.cleanup")(function* (session: Session.Info) {
-      if (!session.revert) return
-      const sessionID = session.id
-      const msgs = yield* sessions.messages({ sessionID })
-      const messageID = session.revert.messageID
-      const remove = [] as MessageV2.WithParts[]
-      let target: MessageV2.WithParts | undefined
-      for (const msg of msgs) {
-        if (msg.info.id < messageID) continue
-        if (msg.info.id > messageID) {
-          remove.push(msg)
-          continue
-        }
-        if (session.revert.partID) {
-          target = msg
-          continue
-        }
-        remove.push(msg)
-      }
-      for (const msg of remove) {
-        yield* sync.run(MessageV2.Event.Removed, {
-          sessionID,
-          messageID: msg.info.id,
-        })
-      }
-      if (session.revert.partID && target) {
-        const partID = session.revert.partID
-        const idx = target.parts.findIndex((part) => part.id === partID)
-        if (idx >= 0) {
-          const removeParts = target.parts.slice(idx)
-          target.parts = target.parts.slice(0, idx)
-          for (const part of removeParts) {
-            yield* sync.run(MessageV2.Event.PartRemoved, {
-              sessionID,
-              messageID: target.info.id,
-              partID: part.id,
-            })
-          }
-        }
-      }
-      yield* sessions.clearRevert(sessionID)
+      yield* timeline.commitPending({ sessionID: session.id })
     })
 
     return Service.of({ revert, unrevert, cleanup })
   }),
 )
 
-export const defaultLayer = Layer.suspend(() =>
-  layer.pipe(
-    Layer.provide(SessionRunState.defaultLayer),
-    Layer.provide(Session.defaultLayer),
-    Layer.provide(Snapshot.defaultLayer),
-    Layer.provide(Storage.defaultLayer),
-    Layer.provide(Bus.layer),
-    Layer.provide(SessionSummary.defaultLayer),
-    Layer.provide(SyncEvent.defaultLayer),
-  ),
-)
+export const defaultLayer = Layer.suspend(() => layer.pipe(Layer.provide(SessionTimeline.defaultLayer)))
 
 export * as SessionRevert from "./revert"

packages/opencode/src/session/schema.ts

@@ -33,3 +33,6 @@ export const PartID = Schema.String.check(Schema.isStartsWith("prt")).pipe(
 )
 
 export type PartID = Schema.Schema.Type<typeof PartID>
+
+export const RewindFilePolicy = Schema.Union([Schema.Literal("revert"), Schema.Literal("keep")])
+export type RewindFilePolicy = Schema.Schema.Type<typeof RewindFilePolicy>

packages/opencode/src/session/session.ts

@@ -30,7 +30,7 @@ import { InstanceState } from "@/effect/instance-state"
 import { Snapshot } from "@/snapshot"
 import { ProjectID } from "../project/schema"
 import { WorkspaceID } from "../control-plane/schema"
-import { SessionID, MessageID, PartID } from "./schema"
+import { SessionID, MessageID, PartID, RewindFilePolicy } from "./schema"
 import { ModelID, ProviderID } from "@/provider/schema"
 
 import type { Provider } from "@/provider/provider"
@@ -166,6 +166,7 @@ const Time = Schema.Struct({
 const Revert = Schema.Struct({
   messageID: MessageID,
   partID: optionalOmitUndefined(PartID),
+  files: optionalOmitUndefined(RewindFilePolicy),
   snapshot: optionalOmitUndefined(Schema.String),
   diff: optionalOmitUndefined(Schema.String),
 })

packages/opencode/src/session/timeline.ts

@@ -0,0 +1,159 @@
+import { Effect, Layer, Context, Schema } from "effect"
+import { Bus } from "@/bus"
+import { Snapshot } from "@/snapshot"
+import { Storage } from "@/storage/storage"
+import { zod } from "@opencode-ai/core/effect-zod"
+import { withStatics } from "@opencode-ai/core/schema"
+import * as Session from "./session"
+import { MessageV2 } from "./message-v2"
+import { SessionID, MessageID, PartID, RewindFilePolicy } from "./schema"
+import { SessionRunState } from "./run-state"
+import { SessionSummary } from "./summary"
+
+export const RewindInput = Schema.Struct({
+  sessionID: SessionID,
+  messageID: MessageID,
+  partID: Schema.optional(PartID),
+  files: Schema.optional(RewindFilePolicy),
+}).pipe(withStatics((s) => ({ zod: zod(s) })))
+export type RewindInput = Schema.Schema.Type<typeof RewindInput>
+
+export interface Interface {
+  readonly rewind: (input: RewindInput) => Effect.Effect<Session.Info>
+  readonly restore: (input: { sessionID: SessionID }) => Effect.Effect<Session.Info>
+  readonly commitPending: (input: { sessionID: SessionID }) => Effect.Effect<void>
+}
+
+export class Service extends Context.Service<Service, Interface>()("@opencode/SessionTimeline") {}
+
+export const layer = Layer.effect(
+  Service,
+  Effect.gen(function* () {
+    const sessions = yield* Session.Service
+    const snap = yield* Snapshot.Service
+    const storage = yield* Storage.Service
+    const bus = yield* Bus.Service
+    const summary = yield* SessionSummary.Service
+    const state = yield* SessionRunState.Service
+
+    const rewind = Effect.fn("SessionTimeline.rewind")(function* (input: RewindInput) {
+      yield* state.assertNotBusy(input.sessionID)
+      const all = yield* sessions.messages({ sessionID: input.sessionID })
+      const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+      const files = input.files ?? "revert"
+      let lastUser: MessageV2.User | undefined
+      let rev: Session.Info["revert"]
+      const patches: Snapshot.Patch[] = []
+      const range: MessageV2.WithParts[] = []
+
+      for (const msg of all) {
+        if (msg.info.role === "user") lastUser = msg.info
+        const remaining = []
+        for (const part of msg.parts) {
+          if (rev) {
+            if (files === "revert" && part.type === "patch") patches.push(part)
+            continue
+          }
+
+          if ((msg.info.id === input.messageID && !input.partID) || part.id === input.partID) {
+            const partID = remaining.some((item) => ["text", "tool"].includes(item.type)) ? input.partID : undefined
+            rev = {
+              messageID: !partID && lastUser ? lastUser.id : msg.info.id,
+              partID,
+              ...(files === "keep" && { files }),
+            }
+          }
+          remaining.push(part)
+        }
+        if (rev) range.push(msg)
+      }
+
+      if (!rev) return session
+
+      if (session.revert?.snapshot) yield* snap.restore(session.revert.snapshot)
+      if (files === "revert") {
+        rev.snapshot = session.revert?.snapshot ?? (yield* snap.track())
+        yield* snap.revert(patches)
+        if (rev.snapshot) rev.diff = yield* snap.diff(rev.snapshot)
+      }
+      const diffs = yield* summary.computeDiff({ messages: range })
+      yield* storage.write(["session_diff", input.sessionID], diffs).pipe(Effect.ignore)
+      yield* bus.publish(Session.Event.Diff, { sessionID: input.sessionID, diff: diffs })
+      yield* sessions.setRevert({
+        sessionID: input.sessionID,
+        revert: rev,
+        summary: {
+          additions: diffs.reduce((sum, x) => sum + x.additions, 0),
+          deletions: diffs.reduce((sum, x) => sum + x.deletions, 0),
+          files: diffs.length,
+        },
+      })
+      return yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+    })
+
+    const restore = Effect.fn("SessionTimeline.restore")(function* (input: { sessionID: SessionID }) {
+      yield* state.assertNotBusy(input.sessionID)
+      const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+      if (!session.revert) return session
+      if (session.revert.files !== "keep" && session.revert.snapshot) yield* snap.restore(session.revert.snapshot)
+      yield* sessions.clearRevert(input.sessionID)
+      return yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+    })
+
+    const commitPending = Effect.fn("SessionTimeline.commitPending")(function* (input: { sessionID: SessionID }) {
+      const session = yield* sessions.get(input.sessionID).pipe(Effect.orDie)
+      if (!session.revert) return
+      const sessionID = session.id
+      const msgs = yield* sessions.messages({ sessionID })
+      const messageID = session.revert.messageID
+      const remove = [] as MessageV2.WithParts[]
+      let target: MessageV2.WithParts | undefined
+      for (const msg of msgs) {
+        if (msg.info.id < messageID) continue
+        if (msg.info.id > messageID) {
+          remove.push(msg)
+          continue
+        }
+        if (session.revert.partID) {
+          target = msg
+          continue
+        }
+        remove.push(msg)
+      }
+      for (const msg of remove) {
+        yield* sessions.removeMessage({
+          sessionID,
+          messageID: msg.info.id,
+        })
+      }
+      if (session.revert.partID && target) {
+        const idx = target.parts.findIndex((part) => part.id === session.revert?.partID)
+        if (idx >= 0) {
+          for (const part of target.parts.slice(idx)) {
+            yield* sessions.removePart({
+              sessionID,
+              messageID: target.info.id,
+              partID: part.id,
+            })
+          }
+        }
+      }
+      yield* sessions.clearRevert(sessionID)
+    })
+
+    return Service.of({ rewind, restore, commitPending })
+  }),
+)
+
+export const defaultLayer = Layer.suspend(() =>
+  layer.pipe(
+    Layer.provide(SessionRunState.defaultLayer),
+    Layer.provide(Session.defaultLayer),
+    Layer.provide(Snapshot.defaultLayer),
+    Layer.provide(Storage.defaultLayer),
+    Layer.provide(Bus.layer),
+    Layer.provide(SessionSummary.defaultLayer),
+  ),
+)
+
+export * as SessionTimeline from "./timeline"

packages/opencode/test/session/prompt.test.ts

@@ -30,8 +30,8 @@ import { SessionSummary } from "../../src/session/summary"
 import { Instruction } from "../../src/session/instruction"
 import { SessionProcessor } from "../../src/session/processor"
 import { SessionPrompt } from "../../src/session/prompt"
-import { SessionRevert } from "../../src/session/revert"
 import { SessionRunState } from "../../src/session/run-state"
+import { SessionTimeline } from "../../src/session/timeline"
 import { MessageID, PartID, SessionID } from "../../src/session/schema"
 import { SessionStatus } from "../../src/session/status"
 import { SessionV2 } from "../../src/v2/session"
@@ -199,7 +199,7 @@ function makeHttp() {
   return Layer.mergeAll(
     TestLLMServer.layer,
     SessionPrompt.layer.pipe(
-      Layer.provide(SessionRevert.defaultLayer),
+      Layer.provide(SessionTimeline.defaultLayer),
       Layer.provide(Image.defaultLayer),
       Layer.provide(summary),
       Layer.provideMerge(run),

packages/opencode/test/session/revert-compact.test.ts

@@ -5,6 +5,7 @@ import { Effect, Layer } from "effect"
 import { Session } from "@/session/session"
 import { ModelID, ProviderID } from "../../src/provider/schema"
 import { SessionRevert } from "../../src/session/revert"
+import { SessionTimeline } from "../../src/session/timeline"
 import { MessageV2 } from "../../src/session/message-v2"
 import { Snapshot } from "../../src/snapshot"
 import * as Log from "@opencode-ai/core/util/log"
@@ -18,6 +19,7 @@ void Log.init({ print: false })
 const env = Layer.mergeAll(
   Session.defaultLayer,
   SessionRevert.defaultLayer,
+  SessionTimeline.defaultLayer,
   Snapshot.defaultLayer,
   CrossSpawnSpawner.defaultLayer,
 )
@@ -96,6 +98,51 @@ const tokens = {
   cache: { read: 0, write: 0 },
 }
 
+const fileTurn = Effect.fn("test.fileTurn")(function* (input: {
+  sessionID: SessionID
+  dir: string
+  file: string
+  content: string
+}) {
+  const session = yield* Session.Service
+  const snapshot = yield* Snapshot.Service
+  const userMsg = yield* user(input.sessionID)
+  yield* text(input.sessionID, userMsg.id, `${input.file}:${input.content}`)
+  const assistantMsg = yield* assistant(input.sessionID, userMsg.id, input.dir)
+  const before = yield* snapshot.track()
+  if (!before) throw new Error("expected snapshot")
+  yield* write(path.join(input.dir, input.file), input.content)
+  const after = yield* snapshot.track()
+  if (!after) throw new Error("expected snapshot")
+  const patch = yield* snapshot.patch(before)
+  yield* session.updatePart({
+    id: PartID.ascending(),
+    messageID: assistantMsg.id,
+    sessionID: input.sessionID,
+    type: "step-start",
+    snapshot: before,
+  })
+  yield* session.updatePart({
+    id: PartID.ascending(),
+    messageID: assistantMsg.id,
+    sessionID: input.sessionID,
+    type: "step-finish",
+    reason: "stop",
+    snapshot: after,
+    cost: 0,
+    tokens,
+  })
+  yield* session.updatePart({
+    id: PartID.ascending(),
+    messageID: assistantMsg.id,
+    sessionID: input.sessionID,
+    type: "patch",
+    hash: patch.hash,
+    files: patch.files,
+  })
+  return { user: userMsg, assistant: assistantMsg }
+})
+
 describe("revert + compact workflow", () => {
   it.live(
     "should properly handle compact command after revert",
@@ -636,4 +683,58 @@ describe("revert + compact workflow", () => {
       { git: true },
     ),
   )
+
+  it.live(
+    "timeline rewind can keep file changes while hiding future messages",
+    provideTmpdirInstance(
+      (dir) =>
+        Effect.gen(function* () {
+          const session = yield* Session.Service
+          const timeline = yield* SessionTimeline.Service
+
+          yield* write(path.join(dir, "a.txt"), "a0")
+
+          const info = yield* session.create({})
+          const sid = info.id
+          const turn = yield* fileTurn({ sessionID: sid, dir, file: "a.txt", content: "a1" })
+
+          const rewound = yield* timeline.rewind({ sessionID: sid, messageID: turn.user.id, files: "keep" })
+          expect(rewound.revert?.messageID).toBe(turn.user.id)
+          expect(rewound.revert?.files).toBe("keep")
+          expect(yield* read(path.join(dir, "a.txt"))).toBe("a1")
+
+          yield* timeline.commitPending({ sessionID: rewound.id })
+          expect((yield* session.messages({ sessionID: sid })).map((msg) => msg.info.id)).toEqual([])
+          expect(yield* read(path.join(dir, "a.txt"))).toBe("a1")
+        }),
+      { git: true },
+    ),
+  )
+
+  it.live(
+    "timeline restore keeps files for keep-file rewinds",
+    provideTmpdirInstance(
+      (dir) =>
+        Effect.gen(function* () {
+          const session = yield* Session.Service
+          const timeline = yield* SessionTimeline.Service
+
+          yield* write(path.join(dir, "a.txt"), "a0")
+
+          const info = yield* session.create({})
+          const sid = info.id
+          const turn = yield* fileTurn({ sessionID: sid, dir, file: "a.txt", content: "a1" })
+
+          yield* timeline.rewind({ sessionID: sid, messageID: turn.user.id, files: "keep" })
+          const restored = yield* timeline.restore({ sessionID: sid })
+          expect(restored.revert).toBeUndefined()
+          expect((yield* session.messages({ sessionID: sid })).map((msg) => msg.info.id)).toEqual([
+            turn.user.id,
+            turn.assistant.id,
+          ])
+          expect(yield* read(path.join(dir, "a.txt"))).toBe("a1")
+        }),
+      { git: true },
+    ),
+  )
 })

packages/opencode/test/session/schema-decoding.test.ts

@@ -4,6 +4,7 @@ import { Schema } from "effect"
 import { Session } from "@/session/session"
 import { SessionPrompt } from "../../src/session/prompt"
 import { SessionRevert } from "../../src/session/revert"
+import { SessionTimeline } from "../../src/session/timeline"
 import { SessionStatus } from "../../src/session/status"
 import { SessionSummary } from "../../src/session/summary"
 import { Todo } from "../../src/session/todo"
@@ -218,8 +219,8 @@ describe("Session input schemas", () => {
 describe("SessionRevert.RevertInput", () => {
   const decode = decodeUnknown(SessionRevert.RevertInput)
 
-  test("messageID is required, partID is optional", () => {
-    const withPart = { sessionID, messageID, partID }
+  test("messageID is required, partID and file policy are optional", () => {
+    const withPart = { sessionID, messageID, partID, files: "keep" as const }
     expect(decode(withPart)).toEqual(withPart)
     expect(SessionRevert.RevertInput.zod.parse(withPart)).toEqual(withPart)
 
@@ -232,6 +233,20 @@ describe("SessionRevert.RevertInput", () => {
   })
 })
 
+describe("SessionTimeline.RewindInput", () => {
+  const decode = decodeUnknown(SessionTimeline.RewindInput)
+
+  test("accepts optional file policy", () => {
+    const keep = { sessionID, messageID, files: "keep" as const }
+    expect(decode(keep)).toEqual(keep)
+    expect(SessionTimeline.RewindInput.zod.parse(keep)).toEqual(keep)
+
+    const revert = { sessionID, messageID, partID, files: "revert" as const }
+    expect(decode(revert)).toEqual(revert)
+    expect(SessionTimeline.RewindInput.zod.parse(revert)).toEqual(revert)
+  })
+})
+
 describe("SessionSummary.DiffInput", () => {
   const decode = decodeUnknown(SessionSummary.DiffInput)
 

packages/opencode/test/session/session-schema.test.ts

@@ -63,13 +63,14 @@ describe("Session schema", () => {
       revert: {
         messageID: MessageID.ascending(),
         partID: undefined,
+        files: undefined,
         snapshot: undefined,
         diff: undefined,
       },
     }) as Record<string, unknown>
 
     expect(Object.hasOwn(encoded.summary as Record<string, unknown>, "diffs")).toBe(false)
-    for (const key of ["partID", "snapshot", "diff"]) {
+    for (const key of ["partID", "files", "snapshot", "diff"]) {
       expect(Object.hasOwn(encoded.revert as Record<string, unknown>, key)).toBe(false)
     }
   })

packages/opencode/test/session/snapshot-tool-race.test.ts

@@ -19,8 +19,8 @@ import path from "path"
 import { Session } from "@/session/session"
 import { LLM } from "../../src/session/llm"
 import { SessionPrompt } from "../../src/session/prompt"
-import { SessionRevert } from "../../src/session/revert"
 import { SessionSummary } from "../../src/session/summary"
+import { SessionTimeline } from "../../src/session/timeline"
 import { MessageV2 } from "../../src/session/message-v2"
 import * as Log from "@opencode-ai/core/util/log"
 import { provideTmpdirServer } from "../fixture/fixture"
@@ -150,7 +150,7 @@ function makeHttp() {
     TestLLMServer.layer,
     SessionSummary.defaultLayer,
     SessionPrompt.layer.pipe(
-      Layer.provide(SessionRevert.defaultLayer),
+      Layer.provide(SessionTimeline.defaultLayer),
       Layer.provide(Image.defaultLayer),
       Layer.provide(SessionSummary.defaultLayer),
       Layer.provideMerge(run),

packages/sdk/js/src/v2/gen/sdk.gen.ts

@@ -3844,6 +3844,7 @@ export class Session2 extends HeyApiClient {
       workspace?: string
       messageID?: string
       partID?: string
+      files?: "revert" | "keep"
     },
     options?: Options<never, ThrowOnError>,
   ) {
@@ -3857,6 +3858,7 @@ export class Session2 extends HeyApiClient {
             { in: "query", key: "workspace" },
             { in: "body", key: "messageID" },
             { in: "body", key: "partID" },
+            { in: "body", key: "files" },
           ],
         },
       ],

packages/sdk/js/src/v2/gen/types.gen.ts

@@ -5,6 +5,12 @@ export type ClientOptions = {
 }
 
 export type Event =
+  | EventTuiPromptAppend
+  | EventTuiCommandExecute
+  | EventTuiToastShow1
+  | EventTuiSessionSelect
+  | EventServerConnected
+  | EventGlobalDisposed
   | EventServerInstanceDisposed
   | EventFileEdited
   | EventFileWatcherUpdated
@@ -24,10 +30,6 @@ export type Event =
   | EventSessionStatus
   | EventSessionIdle
   | EventSessionCompacted
-  | EventTuiPromptAppend
-  | EventTuiCommandExecute
-  | EventTuiToastShow1
-  | EventTuiSessionSelect
   | EventMcpToolsChanged
   | EventMcpBrowserOpenFailed
   | EventCommandExecuted
@@ -75,8 +77,6 @@ export type Event =
   | EventSessionNextCompactionStarted
   | EventSessionNextCompactionDelta
   | EventSessionNextCompactionEnded
-  | EventServerConnected
-  | EventGlobalDisposed
 
 export type OAuth = {
   type: "oauth"
@@ -103,6 +103,61 @@ export type WellKnownAuth = {
 
 export type Auth = OAuth | ApiAuth | WellKnownAuth
 
+export type EventTuiPromptAppend = {
+  id: string
+  type: "tui.prompt.append"
+  properties: {
+    text: string
+  }
+}
+
+export type EventTuiCommandExecute = {
+  id: string
+  type: "tui.command.execute"
+  properties: {
+    command:
+      | "session.list"
+      | "session.new"
+      | "session.share"
+      | "session.interrupt"
+      | "session.compact"
+      | "session.page.up"
+      | "session.page.down"
+      | "session.line.up"
+      | "session.line.down"
+      | "session.half.page.up"
+      | "session.half.page.down"
+      | "session.first"
+      | "session.last"
+      | "prompt.clear"
+      | "prompt.submit"
+      | "agent.cycle"
+      | string
+  }
+}
+
+export type EventTuiToastShow = {
+  id: string
+  type: "tui.toast.show"
+  properties: {
+    title?: string
+    message: string
+    variant: "info" | "success" | "warning" | "error"
+    duration?: number
+  }
+}
+
+export type EventTuiSessionSelect = {
+  id: string
+  type: "tui.session.select"
+  properties: {
+    /**
+     * Session ID to navigate to
+     */
+    sessionID: string
+  }
+}
+
 export type PermissionRequest = {
   id: string
   sessionID: string
@@ -280,61 +335,6 @@ export type SessionStatus =
       type: "busy"
     }
 
-export type EventTuiPromptAppend = {
-  id: string
-  type: "tui.prompt.append"
-  properties: {
-    text: string
-  }
-}
-
-export type EventTuiCommandExecute = {
-  id: string
-  type: "tui.command.execute"
-  properties: {
-    command:
-      | "session.list"
-      | "session.new"
-      | "session.share"
-      | "session.interrupt"
-      | "session.compact"
-      | "session.page.up"
-      | "session.page.down"
-      | "session.line.up"
-      | "session.line.down"
-      | "session.half.page.up"
-      | "session.half.page.down"
-      | "session.first"
-      | "session.last"
-      | "prompt.clear"
-      | "prompt.submit"
-      | "agent.cycle"
-      | string
-  }
-}
-
-export type EventTuiToastShow = {
-  id: string
-  type: "tui.toast.show"
-  properties: {
-    title?: string
-    message: string
-    variant: "info" | "success" | "warning" | "error"
-    duration?: number
-  }
-}
-
-export type EventTuiSessionSelect = {
-  id: string
-  type: "tui.session.select"
-  properties: {
-    /**
-     * Session ID to navigate to
-     */
-    sessionID: string
-  }
-}
-
 export type Project = {
   id: string
   worktree: string
@@ -762,6 +762,7 @@ export type Session = {
   revert?: {
     messageID: string
     partID?: string
+    files?: "revert" | "keep"
     snapshot?: string
     diff?: string
   }
@@ -778,6 +779,12 @@ export type GlobalEvent = {
   project?: string
   workspace?: string
   payload:
+    | EventTuiPromptAppend
+    | EventTuiCommandExecute
+    | EventTuiToastShow
+    | EventTuiSessionSelect
+    | EventServerConnected
+    | EventGlobalDisposed
     | EventServerInstanceDisposed
     | EventFileEdited
     | EventFileWatcherUpdated
@@ -797,10 +804,6 @@ export type GlobalEvent = {
     | EventSessionStatus
     | EventSessionIdle
     | EventSessionCompacted
-    | EventTuiPromptAppend
-    | EventTuiCommandExecute
-    | EventTuiToastShow
-    | EventTuiSessionSelect
     | EventMcpToolsChanged
     | EventMcpBrowserOpenFailed
     | EventCommandExecuted
@@ -848,8 +851,6 @@ export type GlobalEvent = {
     | EventSessionNextCompactionStarted
     | EventSessionNextCompactionDelta
     | EventSessionNextCompactionEnded
-    | EventServerConnected
-    | EventGlobalDisposed
     | SyncEventMessageUpdated
     | SyncEventMessageRemoved
     | SyncEventMessagePartUpdated
@@ -1450,6 +1451,7 @@ export type GlobalSession = {
   revert?: {
     messageID: string
     partID?: string
+    files?: "revert" | "keep"
     snapshot?: string
     diff?: string
   }
@@ -1913,6 +1915,7 @@ export type SyncEventSessionUpdated = {
       revert?: {
         messageID: string
         partID?: string
+        files?: "revert" | "keep"
         snapshot?: string
         diff?: string
       } | null
@@ -2330,6 +2333,22 @@ export type SyncEventSessionNextCompactionEnded = {
   }
 }
 
+export type EventServerConnected = {
+  id: string
+  type: "server.connected"
+  properties: {
+    [key: string]: unknown
+  }
+}
+
+export type EventGlobalDisposed = {
+  id: string
+  type: "global.disposed"
+  properties: {
+    [key: string]: unknown
+  }
+}
+
 export type EventServerInstanceDisposed = {
   id: string
   type: "server.instance.disposed"
@@ -3044,22 +3063,6 @@ export type EventSessionNextCompactionEnded = {
   }
 }
 
-export type EventServerConnected = {
-  id: string
-  type: "server.connected"
-  properties: {
-    [key: string]: unknown
-  }
-}
-
-export type EventGlobalDisposed = {
-  id: string
-  type: "global.disposed"
-  properties: {
-    [key: string]: unknown
-  }
-}
-
 export type SessionInfo = {
   id: string
   parentID?: string
@@ -5935,6 +5938,7 @@ export type SessionRevertData = {
   body?: {
     messageID: string
     partID?: string
+    files?: "revert" | "keep"
   }
   path: {
     sessionID: string