Analyze Bundle

Documents

analyze-bundle

Analyze Bundle is an Agent Skill for documents published in the vercel-labs/dev3000 repository on GitHub: a SKILL.md instruction file an AI agent can load to do this task.

Convert Next.js bundle analyzer data to NDJSON and explore it

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QUICK START

How to use this skill

Bring this guide into your coding agent with a prompt tailored to the tool you use.

Open your project in Codex.
Copy and paste the prompt below.
Review files and risks before approving any action.

Prompt to paste

Inspect the Agent Skill at https://github.com/vercel-labs/dev3000/blob/HEAD/.agents/skills/analyze-bundle/SKILL.md and all supporting files. Report provenance, permissions, scripts, dependencies, and security risks. Propose an exact installation into .agents/skills/analyze-bundle, but wait for my approval before writing files or running scripts.

Copying this prompt does not install or run the skill. Review third-party files before use.

analyze-to-ndjson

Converts Next.js bundle analyzer binary .data files into grep/jq-friendly NDJSON.

Analyze artifacts

This workflow pre-generates analyzer artifacts in:

.next/diagnostics/analyze/ndjson/routes.ndjson
.next/diagnostics/analyze/ndjson/sources.ndjson
.next/diagnostics/analyze/ndjson/output_files.ndjson
.next/diagnostics/analyze/ndjson/module_edges.ndjson
.next/diagnostics/analyze/ndjson/modules.ndjson

Focus on reading these files and using their evidence to prioritize changes.

Output files

File	What's in it
`modules.ndjson`	Global module registry (`id`, `ident`, `path`)
`module_edges.ndjson`	Module dependency graph (`from`, `to`, `kind`: sync/async)
`sources.ndjson`	Per-route source tree with sizes and environment flags
`chunk_parts.ndjson`	Granular size data: one line per (source, output_file) pair
`output_files.ndjson`	Per-route output files with aggregated sizes
`routes.ndjson`	Route-level summaries

Browsing the output

Route overview

jq -s 'sort_by(-.total_compressed_size)' .next/diagnostics/analyze/ndjson/routes.ndjson

Find large sources

jq -s '
  group_by(.full_path)
  | map(max_by(.compressed_size))
  | sort_by(-.compressed_size)
  | .[0:10]
  | .[] | {full_path, compressed_size, size, route}
' .next/diagnostics/analyze/ndjson/sources.ndjson

Client-side JS

grep '"client":true' .next/diagnostics/analyze/ndjson/sources.ndjson \
  | grep '"js":true' \
  | jq -s 'sort_by(-.compressed_size) | .[0:10] | .[] | {full_path, compressed_size}'

Module dependencies

grep '"from":42,' .next/diagnostics/analyze/ndjson/module_edges.ndjson | jq .to
grep '"to":42,' .next/diagnostics/analyze/ndjson/module_edges.ndjson | jq .from
grep 'react-dom' .next/diagnostics/analyze/ndjson/modules.ndjson | jq '{id, path}'

Output files for a route

grep '"route":"/"' .next/diagnostics/analyze/ndjson/output_files.ndjson \
  | jq -s 'sort_by(-.total_compressed_size) | .[0:10] | .[] | {filename, total_compressed_size, num_parts}'

Directory tree for a route

grep '"route":"/"' .next/diagnostics/analyze/ndjson/sources.ndjson \
  | jq 'select(.parent_id == null)'