Readback

Hear your AI coding agent's replies in a Speechify voice, with the words highlighted as they are spoken.

Claude Code works through a task. Readback reads the notes Claude writes between tool calls as they land, then condenses the finished reply to a few spoken sentences, all in the VS Code sidebar with each word lit as it is said. The full reply is one click away. Click a word to jump to it. Step by sentence. Cycle the speed. Pick any voice your Speechify key can render, including your own clone, and hear a sample of each before you choose.

Install

Paste this into Claude Code:

Install the Readback VS Code extension, then run its "Install the Claude Code hook" command and tell me when it is done.

Or by hand: install the extension, then either answer the prompt that appears on first start, click Readback in the status bar, or run Readback: Set Speechify API key from the Command Palette. Then press Install the hook in the Readback view.

You need a Speechify API key. Create one at https://platform.speechify.ai/api-keys?utm_source=github&utm_medium=readme&utm_campaign=readback. Readback keeps it in VS Code's secret storage and every reply you listen to bills your own workspace.

After a reload, click once anywhere in the VS Code window before you expect to hear anything. The browser inside VS Code keeps audio silent until then, and the player shows a card until it has played once. Replies that arrive before that queue up.

How it works

• Five hooks in ~/.claude/settings.json, MessageDisplay, PreToolUse, Notification, UserPromptSubmit and Stop, post each assistant message, each tool call, each permission prompt left waiting, each prompt of yours and each finished turn to Readback. The hook is ten lines of POSIX shell and curl (the same lines in PowerShell on Windows). It needs no runtime on your PATH and never decides anything itself.
• Codex CLI can be a second source: a Stop hook in ~/.codex/hooks.json posts each finished turn the same way. Codex has no per-message hook, so its notes between tool calls are not read. See Codex below.
• A message followed by a tool call was a note written before it, and Readback reads it as it stands while the tool runs. A message followed by Stop is the finished reply and gets condensed, unless it is under 500 characters already, which is read as it stands. Turn the notes off with readback.progress.
• A permission prompt that has waited about six seconds (Claude Code's own threshold for the permission_prompt notification) is read at once, ahead of whatever is playing: "Claude is waiting for your permission to run npm install, in readback." The tool call comes from the PreToolUse that preceded it. Whatever was playing carries on afterwards. Turn it off with readback.alerts.
• When you submit your next prompt, Readback stops reading: the reply it was on has been read. A reply still being condensed when you type lands in the list without playing.
• Each turn opens with a one-word lead-in, the project's name, that renders once and plays from the cache, so you hear that a turn has started within a few milliseconds while its first paragraph renders. The time is shown next to it, not spoken.
• Readback condenses the reply with claude -p on Sonnet, on your own Claude subscription, so it holds no model key. The run loads no settings and is marked so the hook ignores it, which is what stops a reply about a reply. If claude is missing or the run fails, you hear the full reply instead. Turn it off with readback.summarize.
• Readback flattens the text to plain prose (code blocks become "code omitted", tables a short note, links their text), splits it into paragraphs, and synthesizes each one through /v1/audio/speech as the player reaches it.
• Speech marks come back with character offsets into the exact text sent, and that is what drives the highlight. No guessing, no token alignment.
• Renders are cached on disk by text, voice and model. Replaying is free. Changing voice re-renders.

Commands

Settings

Languages

Readback speaks whatever language Claude writes in, as long as the voice speaks it too. On simba-3.5, the default, every voice speaks its 48 languages. On simba-3.2, which is English only, a voice in another language renders on simba-3.0, which speaks German, Spanish (Spain and Mexico), French, Italian and Brazilian Portuguese. The voice's locale goes with every request.

To have Claude answer in Spanish, add language to ~/.claude/settings.json, or to a project's .claude/settings.json for that project only:

{
  "language": "spanish"
}

Claude Code applies it straight away. Readback reads the same setting:

• If you have not picked a voice, it uses one in that language.
• If you have, it keeps yours. The voice picker lists that language first and says when your voice speaks a different one. Pick a voice from that group.

The condensed summary is written in the reply's language, so it matches what Claude wrote. The catch-up lead-in ("Catching up on 3 replies") is still English. If Claude writes in a language no voice speaks, such as Japanese, the reply is read by your voice anyway and will not sound right.

Several windows

Each window shows and speaks only its own project's turns. A turn belongs to a window when the folder Claude Code ran in is inside one of its workspace folders, or contains one (running Claude at a monorepo's root while the window has a sub-project open is the same project). A turn that matches no open window is not read.

Catching up

A reply counts as heard when it started playing while this VS Code window was focused. One that played to an empty room, or that waited because autoplay was off, stays unheard. Catch me up (the history button, or the command) takes every unheard reply in the list, oldest first, and has claude -p brief them together: what landed, what is still open, what waits on you, grouped by project. The briefing is listed as its own turn and plays; the replies it covers stay in the list and count as heard. Without claude, or with readback.summarize off, the same replies are read one after another instead. At most 20 are read in detail; older ones are counted in the lead-in.

Codex

Open the settings panel and press Install on the Codex CLI row, or run Readback: Install the Codex hook. This writes one Stop entry to ~/.codex/hooks.json, next to whatever is already there. Codex runs a new hook only after you have trusted it once: open Codex, run /hooks, and approve Readback. Until then nothing arrives. Condensing still runs through claude -p when it is installed; without it Codex replies are read in full.

The player

Play, pause, back and forward a sentence, stop. Space, left and right do the same when the player has focus. The progress line tracks the current paragraph. The autoplay toggle decides whether a new reply plays at once or waits, marked with a dot, for you to press play. The speed pill cycles from 0.75× to 2×; the voice pill opens the voice picker. Each turn has its own play button, and a condensed turn has a "Full reply" section with one of its own.

Limits

• Claude Code and Codex CLI are the sources. The Claude Code hook fires for sessions in a terminal and in the Claude Code panel in VS Code.
• On Windows the hook is a PowerShell script run through powershell.exe with no shell in between. It has not yet been tried on a Windows machine by us; if you run it there, an issue with what you saw would help.
• Read-along needs speech marks, which the streaming endpoint does not return, so replies are read paragraph by paragraph at up to 2,000 characters per request.

Develop

npm install
npm run typecheck && npm test
npm run build          # dist/extension.js
npm run package        # readback-<version>.vsix

Press F5 in VS Code to run the extension in a development host.

MIT. Built by Speechify. The player's icons are VS Code's codicons (CC BY 4.0).