# StackNext

> Local-first runtime debugging, deterministic diagnostics and Playwright regression evidence for Next.js App Router apps.

> ## 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](https://docs.stacknext.space/index.md): StackNext is a local-first debugging center for Next.js App Router apps, with deterministic diagnostics and Playwright regression evidence.
- [How StackNext works](https://docs.stacknext.space/overview/what-is-stacknext.md): The collector, sample, dashboard, diagnostics, snapshots and regression records that make up StackNext.
- [Core concepts](https://docs.stacknext.space/overview/core-concepts.md): The sample, traces, coverage, diagnostics, snapshots and regression records that StackNext exposes.
- [Limitations](https://docs.stacknext.space/limitations.md): Intentional boundaries of StackNext telemetry, diagnostics and regression evidence.
- [Installation](https://docs.stacknext.space/installation.md): Install StackNext in a Next.js App Router project, initialize it, verify the collector and remove it safely.
- [Quickstart](https://docs.stacknext.space/getting-started/quickstart.md): Install StackNext, start the collector and inspect your first request.
- [Runtime evidence](https://docs.stacknext.space/guides/runtime-evidence.md): Investigate requests, traces, errors and database activity with the dashboard, CLI and read-only MCP tools.
- [Diagnostics](https://docs.stacknext.space/guides/diagnostics.md): The six deterministic Next.js rules, finding statuses, evidence and limits behind every StackNext diagnostic.
- [Snapshots](https://docs.stacknext.space/guides/snapshots.md): Save, inspect, export and import frozen redacted samples without replaying them into the live store.
- [Runtime regression testing](https://docs.stacknext.space/regression-testing.md): Capture Playwright runs, save immutable baselines and compare deterministic runtime evidence.
- [CI integration](https://docs.stacknext.space/ci-integration.md): Run capture, comparison and evidence artifacts in a normal CI job.
- [Playwright integration](https://docs.stacknext.space/playwright-integration.md): Set up the optional fixture, scenario annotations and verified correlation.
- [Custom instrumentation](https://docs.stacknext.space/custom-instrumentation.md): Add application spans and record Server Actions with the @stacknext/next helpers.
- [Instrumentation coverage](https://docs.stacknext.space/instrumentation-coverage.md): Read evidence-based coverage statuses without turning them into a score.
- [Next.js integration](https://docs.stacknext.space/integrations/nextjs.md): How StackNext registers with Next.js, what it captures and how it coexists with an existing OpenTelemetry setup.
- [Database integrations](https://docs.stacknext.space/integrations/database.md): Add Drizzle or Prisma query evidence without capturing SQL bind parameters.
- [MCP server](https://docs.stacknext.space/mcp.md): Connect an AI coding client to StackNext's read-only stdio MCP server.
- [AI agent support](https://docs.stacknext.space/ai-agents/index.md): How StackNext gives coding agents version-matched docs, evidence-first workflows and read-only runtime access.
- [Agent setup](https://docs.stacknext.space/ai-agents/setup.md): Install managed AGENTS.md instructions, the Agent Skill and the read-only MCP server for OpenCode, Codex or Claude Code.
- [Agent workflows](https://docs.stacknext.space/ai-agents/workflows.md): An evidence-first loop for runtime errors, slow requests, diagnostics, regressions and snapshots.
- [Local documentation](https://docs.stacknext.space/ai-agents/local-docs.md): Find version-matched Markdown documentation in installed packages and use the site's AI-readable endpoints.
- [CLI commands](https://docs.stacknext.space/cli/commands.md): Complete reference for the stacknext binary, its commands, options and exit behavior.
- [Configuration](https://docs.stacknext.space/reference/configuration.md): stacknext.config.json fields, defaults and the environment variables stacknext dev sets.
- [MCP tools](https://docs.stacknext.space/reference/mcp-tools.md): The twenty read-only tools, five prompts and response metadata the StackNext MCP server exposes to AI coding agents.
- [Packages and public APIs](https://docs.stacknext.space/reference/packages.md): The StackNext packages you install directly, their public entry points and where version-matched reference lives.
- [Compatibility](https://docs.stacknext.space/compatibility.md): Supported Node.js, Next.js 15 and 16, package manager, Playwright and MCP client combinations, plus what StackNext does not support.
- [Troubleshooting](https://docs.stacknext.space/troubleshooting.md): Diagnose missing telemetry, connection, port, MCP and regression problems.
- [Privacy and data handling](https://docs.stacknext.space/privacy.md): What StackNext collects, how redaction works, where data is stored and when it is deleted.


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