> ## Documentation Index
> Fetch the complete documentation index at: https://docs.stacknext.space/llms.txt
> Use this file to discover all available pages before exploring further.

> ## Agent Instructions
> StackNext documentation is written for developers using StackNext in a Next.js App Router project. Use the getting-started and guides sections to install and operate the product, and the reference section for CLI, configuration, MCP and package surfaces. Version-matched package API reference ships inside each npm package under node_modules/@stacknext/<package>/docs/ and is preferred over this site for installed-version APIs. Diagnostic findings are evidence, not confirmed root causes; regression comparisons are deterministic and report-only. Contributor and repository-maintenance documentation is not part of this site.

# Introduction

> StackNext is a local-first debugging center for Next.js App Router apps, with deterministic diagnostics and Playwright regression evidence.

# StackNext documentation

StackNext shows you what your Next.js app actually did at runtime. It collects
OpenTelemetry spans, Drizzle and Prisma query events and request errors from your
development server, keeps them in a bounded local sample, and exposes that
evidence in a dashboard, a CLI and a read-only MCP server.

It also derives deterministic diagnostic findings from the same sample, freezes
redacted snapshots, and compares Playwright-linked captures against saved
baselines. Everything runs on your machine: there is no account, hosted backend,
AI API client or outbound telemetry.

![StackNext dashboard overview showing request counts, p95 latency, slow requests, recent latency, diagnostic findings and recent errors](https://mintcdn.com/stack-next/wvbZ0Zo0GO0UM1X7/screenshots/overview.png?fit=max\&auto=format\&n=wvbZ0Zo0GO0UM1X7\&q=85\&s=15920e8525b5548861d5772ebb134e45)

![StackNext dashboard overview showing request counts, p95 latency, slow requests, recent latency, diagnostic findings and recent errors](https://mintcdn.com/stack-next/wvbZ0Zo0GO0UM1X7/screenshots/overview-dark.png?fit=max\&auto=format\&n=wvbZ0Zo0GO0UM1X7\&q=85\&s=7c9e25092218332ce093a2cfffcb3f03)

## Start here

| I want to | Read |
| - | - |
| Install StackNext in my app | [Installation](https://docs.stacknext.space/installation.md) |
| See a first request in the dashboard | [Quickstart](https://docs.stacknext.space/getting-started/quickstart.md) |
| Configure ports, retention and diagnostics | [Configuration](https://docs.stacknext.space/reference/configuration.md) |
| Investigate an error or slow request | [Runtime evidence](https://docs.stacknext.space/guides/runtime-evidence.md) |
| Understand the diagnostic findings | [Diagnostics](https://docs.stacknext.space/guides/diagnostics.md) |
| Save or share a frozen sample | [Snapshots](https://docs.stacknext.space/guides/snapshots.md) |
| Compare a Playwright flow with a baseline | [Regression testing](https://docs.stacknext.space/regression-testing.md) |
| Use StackNext from an AI coding agent | [AI agents](https://docs.stacknext.space/ai-agents.md) |
| Look up a command or field | [Reference](https://docs.stacknext.space/cli/commands.md) |

## Install

```bash theme={null}
npm install --save-dev @stacknext/cli @stacknext/next
npx stacknext init
npx stacknext dev
```

Open the dashboard URL printed at startup, usually
`http://127.0.0.1:4400`, and make a request to your app. `init` never overwrites
an existing instrumentation file; it prints the hook to add instead.

## What StackNext is not

StackNext is a development tool, not production APM. It supports Next.js 15 and
16 with the App Router on the Node.js runtime only. It never captures request or
response bodies, headers, cookies, URL query values or SQL bind parameters, and
it does not run SQL, edit source code or call an AI provider. See
[limitations](https://docs.stacknext.space/limitations.md) and [privacy](https://docs.stacknext.space/privacy.md) for the full boundary.

The npm packages also ship their own version-matched documentation. When you are
writing code against an installed API, read
`node_modules/@stacknext/<package>/docs/` first. See
[local documentation](https://docs.stacknext.space/ai-agents/local-docs.md).


This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.