PR Explainer (Beta) — Narrated Code Tours & Reviews

Saurabh Singh

7 installs

PR Explainer analyzes your code structure before generating anything. It traces dependencies, reads call sites, and classifies changes so tours reference real files at verified line numbers — not hallucinated paths. Run a narrated walkthrough of any PR or uncommitted changes, get severity-graded cod

Installation

Launch VS Code Quick Open (Ctrl+P), paste the following command, and press enter.

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PR Explainer — Narrated Code Tours & Reviews

Walks you through PRs with voice narration and code review findings, grounded in actual code analysis.

What it does

PR Explainer reads your codebase before it reads your diff. It traces imports, resolves dependencies, classifies changes by severity, and picks framework-specific context — then hands all of that to the LLM. The result: tours that reference real files at real line numbers, and review findings that understand how your change fits into the project.

Two main workflows:

Narrated tours — step-by-step audio walkthroughs of PRs, uncommitted changes, or individual files. Each stop highlights a code region and narrates what changed and why.
Code review — severity-graded findings (critical, warning, good practice) shown inline with gutter decorations. Run standalone or combined with tours.

Getting started

Install the extension
Open a project with changes
Cmd+Shift+P → PR Explainer: Explain Code Changes...
Sign in when prompted — no API keys needed

The Smart Diff Picker auto-detects your PR, uncommitted changes, or lets you pick a commit range. First tour takes a few seconds; replays are instant from cache.

Tour modes

Explain Code Changes — The main entry point. Picks up your PR or uncommitted changes automatically, lets you choose detail level, and optionally includes review findings.

Review Code Changes — Same analysis, but focused on finding issues. Each stop shows severity-graded findings with inline gutter markers in the editor.

Explain This File — Deep dive into a single file. Good for onboarding or understanding unfamiliar code.

Code review

When review mode is on (via the "Review Code Changes" command or the includeReview setting), each tour stop includes findings graded by severity:

Critical — breaking changes, security issues, bugs
Warning — code quality issues, missed edge cases
Good practice — things done well worth noting

Findings appear in the narration panel and as colored gutter decorations in the editor. The status bar shows accumulated counts across the tour.

Audio & video

Every tour is narrated with natural TTS. Pick from OpenAI, ElevenLabs, or the free Web Speech API. Pause, skip between stops, mute, or just read the text.

Export any tour as an MP4 with narration and closed captions — useful for async PR reviews or team onboarding. Requires ffmpeg on PATH.

Language & framework support

11 languages: Rust, Go, TypeScript, JavaScript, Python, Java, Kotlin, C#, PHP, Ruby, Scala.

7 framework-specific recipes: React, Next.js, Spring Boot, FastAPI, Django, Gin, Axum. Each recipe knows the framework's idioms — route handlers, middleware patterns, ORM models — so tours explain changes in the right context.

Detail levels

Critical — 3-5 stops, just the important changes
Medium — 5-10 stops, balanced (default)
All — up to 15 stops, comprehensive

Two ways to run

Managed mode (default): Sign in with Google, GitHub, or email. We handle the AI and TTS — no keys needed. Free tier gets 10 tours/month. Pro waitlist open.

Local mode: Set prexplainer.hostedMode to off and add your own API keys. All code stays on your machine. No account, no limits.

Commands

Command	What it does	Shortcut
Explain Code Changes...	Smart diff picker → tour	—
Review Code Changes...	Smart diff picker → review	—
Explain This File	Tour current file	—
Replay Last Tour	Play from cache	—
Export Tour as Video	MP4 with captions	—
Pause Tour	Pause/resume	`Alt+Space`
Mute/Unmute	Toggle voice	`Alt+M`
Previous Stop	Back one stop	`Alt+[`
Next Stop	Forward one stop	`Alt+]`
Stop Tour	Cancel	`Escape`
Sign In / Sign Out	Managed mode auth	—

Settings

LLM

Setting	Description
`prexplainer.llmProvider`	`anthropic`, `openai`, `google`, or auto-detect
`prexplainer.llmModel`	Model name (e.g. `claude-sonnet-4-6`, `gpt-5.4`)
`prexplainer.anthropicApiKey`	Anthropic key (or `PREXPLAINER_ANTHROPIC_API_KEY` env var)
`prexplainer.openaiApiKey`	OpenAI key (or `PREXPLAINER_OPENAI_API_KEY` env var)
`prexplainer.googleApiKey`	Google key (or `PREXPLAINER_GOOGLE_API_KEY` env var)

TTS

Setting	Description
`prexplainer.ttsProvider`	`openai`, `elevenlabs`, `web-speech`, or auto-detect
`prexplainer.ttsModel`	Model (e.g. `gpt-4o-mini-tts`, `tts-1-hd`)
`prexplainer.ttsVoice`	Voice (e.g. `nova`, `alloy`, `Rachel`)
`prexplainer.elevenLabsApiKey`	ElevenLabs key (or `PREXPLAINER_ELEVENLABS_API_KEY` env var)

Other

Setting	Description
`prexplainer.tourLevel`	Default detail: `critical`, `medium`, `all`
`prexplainer.hostedMode`	`on` (managed, default) or `off` (bring your own keys)
`prexplainer.includeReview`	Include code review findings in tours (default: off)

Privacy

Local mode: Code goes directly from your machine to your LLM/TTS provider. We never see it.

Managed mode: Code context is sent to our servers for processing and deleted immediately after. You opt in explicitly by signing in. See our privacy policy.

Tour data and audio are cached locally in .prexplainer/ (gitignored).

Requirements

VS Code 1.95+
Local mode: At least one LLM API key
Video export: ffmpeg and ffprobe on PATH

License

MIT