Latest Package Version Lookup

Query the deps.dev API to get the latest stable version of open source packages.

Supported Ecosystems

Ecosystem	System ID	Example Package
npm	npm	express, @types/node
PyPI	pypi	requests, django
Go	go	github.com/gin-gonic/gin
Cargo	cargo	serde, tokio
Maven	maven	org.springframework:spring-core
NuGet	nuget	Newtonsoft.Json

Workflow

Think step-by-step:

1. Identify the ecosystem from context:

   • package.json or node_modules → npm
   • requirements.txt, pyproject.toml, setup.py → pypi
   • go.mod, go.sum → go
   • Cargo.toml → cargo
   • pom.xml, build.gradle → maven
   • *.csproj, packages.config → nuget
   • If unclear, ask the user

2. Run the get-versions script:

SCRIPT=scripts/get-versions.py
python3 $SCRIPT <system> <pkg1> [pkg2] ...

3. Optionally chain CLI tools to transform output if needed
   • If JSON parsing/filtering is needed, use jq first
   • Then optionally use tools like awk, sort, cut, sed, uniq, column for formatting or aggregation
   • Latest versions only: package + version
   • Deprecation audit: only packages with isDeprecated: true
   • Error triage: only packages with error
   • If no transformation is needed, report directly from script output

Script Usage

Single package:

python3 scripts/get-versions.py npm express

Multiple packages:

python3 scripts/get-versions.py npm express lodash @types/node

Different ecosystems:

python3 scripts/get-versions.py pypi requests django flask
python3 scripts/get-versions.py go github.com/gin-gonic/gin
python3 scripts/get-versions.py maven org.springframework:spring-core

Optional CLI Transform Examples (Agent-Focused)

Use jq after the script output when you need to return only specific fields.

When needed, chain additional CLI tools after jq for sorting, tabular formatting, and summary transforms.

Version summary (package + version):

python3 scripts/get-versions.py npm express lodash @types/node \
  | jq -r '.packages[] | select(has("error") | not) | "\(.package)\t\(.version)"'

Single package version only:

python3 scripts/get-versions.py npm express lodash \
  | jq -r '.packages[] | select(.package == "express") | .version'

Deprecated packages only:

python3 scripts/get-versions.py npm express lodash \
  | jq '.packages[] | select(.isDeprecated == true) | {package, version, isDeprecated}'

Errors only (for troubleshooting):

python3 scripts/get-versions.py npm express nonexistent-pkg \
  | jq '.packages[] | select(has("error")) | {package, error}'

Tabular output with jq | awk (agent-friendly reporting):

python3 scripts/get-versions.py npm express lodash @types/node \
  | jq -r '.packages[] | select(has("error") | not) | "\(.package)\t\(.version)\t\(.publishedAt)"' \
  | awk -F '\t' '{printf "%-20s %-12s %s\n", $1, $2, $3}'

Stable sorted output (jq | sort):

python3 scripts/get-versions.py npm express lodash @types/node \
  | jq -r '.packages[] | select(has("error") | not) | "\(.package)\t\(.version)"' \
  | sort

Output Format

The script outputs JSON with the following structure:

{
  "system": "npm",
  "packages": [
    {
      "package": "express",
      "version": "5.0.0",
      "publishedAt": "2024-09-10T04:40:34Z",
      "isDeprecated": false
    },
    {
      "package": "lodash",
      "version": "4.17.21",
      "publishedAt": "2021-02-20T15:42:16Z",
      "isDeprecated": false
    }
  ]
}

Error response:

{
  "system": "npm",
  "packages": [
    {
      "package": "nonexistent-pkg",
      "error": "HTTP 404: Not Found"
    }
  ]
}

Error Handling

• HTTP 404: Package not found - check spelling and ecosystem
• Network error: deps.dev API may be temporarily unavailable
• No default version: Script returns the latest available version with a note

Rules

• Always use the script instead of manual curl commands
• CLI chaining (jq, awk, etc.) is optional; use it only when it improves clarity or efficiency
• If chaining is used, prefer jq for JSON parsing; use text tools after jq for formatting/aggregation
• The script handles URL encoding automatically
• Multiple packages are fetched in parallel for efficiency
• Use isDeprecated field to warn users about deprecated packages