11 releases

Uses new Rust 2024

0.3.6	Apr 17, 2026
0.3.5	Apr 13, 2026
0.3.0	Mar 15, 2026
0.2.3	Mar 14, 2026
0.1.3	Mar 10, 2026

#1829 in Command line utilities

MIT license

700KB
15K SLoC

srcmap-cli

CLI tool to inspect, validate, compose, and manipulate source maps.

Agent-friendly with --json structured output on all commands and srcmap schema for runtime introspection.

Install

cargo install srcmap-cli

Commands

Command	Description
`info`	Show source map metadata and statistics
`validate`	Validate a source map file
`lookup`	Find original position for a generated position
`resolve`	Find generated position for an original position
`decode`	Decode a VLQ mappings string to JSON
`encode`	Encode decoded mappings JSON back to a VLQ string
`mappings`	List all mappings with pagination
`concat`	Concatenate multiple source maps into one
`remap`	Compose/remap source maps through a transform chain
`symbolicate`	Symbolicate a stack trace using source maps
`scopes`	Inspect scopes-proposal data and variable bindings
`fetch`	Fetch a JS/CSS bundle and its source map from a URL
`sources`	List or extract original sources from a source map
`schema`	Describe all commands as JSON (for agent introspection)

Usage

# Inspect a source map
srcmap info bundle.js.map

# Validate
srcmap validate bundle.js.map

# Look up original position (0-based line:column)
srcmap lookup bundle.js.map 42 12

# Look up with surrounding source context
srcmap lookup bundle.js.map 42 12 --context 5

# Reverse lookup
srcmap resolve bundle.js.map --source src/app.ts 10 0

# Decode VLQ mappings
srcmap decode "AAAA;AACA"

# List mappings with pagination
srcmap mappings bundle.js.map --limit 100 --offset 0

# Concatenate source maps
srcmap concat a.js.map b.js.map -o bundle.js.map

# Remap through upstream maps
srcmap remap minified.js.map --dir ./sourcemaps -o original.js.map

# Symbolicate a stack trace
srcmap symbolicate stacktrace.txt --dir ./sourcemaps

# Inspect scopes-proposal data
srcmap scopes bundle.js.map

# Fetch a bundle and its source map from a URL
srcmap fetch https://cdn.example.com/app.min.js -o ./debug

# List embedded original sources
srcmap sources bundle.js.map

# Extract all original sources to disk
srcmap sources bundle.js.map --extract -o ./src

# All commands support --json for structured output
srcmap info bundle.js.map --json

# Introspect all commands and their arguments
srcmap schema

Features

Structured JSON output — --json flag on all commands for machine-readable output
Agent introspection — srcmap schema describes all commands, args, types, and flags as JSON
stdin support — use - as file argument to read from stdin
Dry run — --dry-run on mutating commands (concat, remap) to validate without writing
Input hardening — rejects control characters, path traversals, and percent-encoding in source names
Output sandboxing — all file writes validated against the current working directory
Remote fetching — srcmap fetch downloads bundles and source maps from URLs, resolving sourceMappingURL automatically
Source extraction — srcmap sources --extract writes embedded sourcesContent to disk with directory structure
Context lines — srcmap lookup --context N shows surrounding original source around a mapped position
Structured errors — error codes (IO_ERROR, PARSE_ERROR, NOT_FOUND, VALIDATION_ERROR, PATH_TRAVERSAL, INVALID_INPUT, FETCH_ERROR) in JSON mode

app srcmap-cli