Up To Date

Rule

Before writing or debugging ANY code that touches an external package or API, fetch the real documentation first. Training data is stale — the docs are the only source of truth for current API contracts, parameter shapes, and SDK method signatures.

Before proceeding, confirm none of these apply:

1. Writing or changing an API call without reading current docs
2. Guessing why an API call silently fails
3. Proposing a fix based on intuition without verifying the actual API contract

If any apply → complete the Mandatory Steps below before writing a single line of code.

When This Triggers

This skill triggers on any of the following — load it BEFORE doing anything else:

Direct triggers (writing code)

• Installing a package (npm install, pip install, brew install)
• Importing or using any third-party library
• Calling any external API (REST, GraphQL, SDK methods)
• Modifying or refactoring existing integration code
• Moving API calls between files (e.g., centralizing into a service module)

Diagnostic triggers (debugging)

• An API returns success but the expected side-effect didn't happen — this is the #1 missed trigger
• User says something "doesn't work" and external services are involved
• The service dashboard shows the request was received but the expected result is missing
• A try/catch is swallowing errors and you need to understand what the API actually expects
• Any 4xx error from an API you haven't checked docs for recently

Refactoring triggers

• Changing how an SDK is initialized (singleton, lazy, etc.)
• Changing how SDK method parameters are constructed
• Moving SDK calls to a different file or module (parameter shapes may need adjustment)

Mandatory Steps

1. Check Version

# What's installed?
cat node_modules/<pkg>/package.json | grep '"version"'
# or: pip show <pkg> | grep Version

# What's latest?
npm info <pkg> version
# or: pip index versions <pkg>

Update if more than 1 major version behind.

2. Fetch Real Docs (pick one or more)

Context7 (preferred for popular libraries):

resolve-library-id → query-docs with specific endpoint/method question

Browser (fetch_webpage):

Fetch the official API reference page for the specific endpoint or method being used

DeepWiki (if available):

Fetch from deepwiki.com for GitHub-based packages

Do NOT skip this step. Do NOT write integration code from memory. Do NOT diagnose failures from memory.

3. Compare Code vs Docs

Check for mismatches:

• Parameters code sends vs parameters docs accept
• Value types and shapes — does the parameter expect a specific type, object structure, or callback signature?
• Endpoint paths code hits vs current paths
• Response shape code expects vs current shape
• Required vs optional fields
• Removed or renamed parameters
• How the SDK expects values to be constructed — wrapper functions, factory methods, specific class instances vs plain objects

4. After Changes

• Remove deprecated env vars and parameters
• Update all call sites
• Build to verify types
• Test live and verify the actual downstream effect — don't just check the HTTP status code. Confirm the resource appears where expected (service dashboard, database, UI). A 200 with a valid-looking response body can still mean nothing happened.

Common Failure Patterns

Anti-Patterns

Decision Flowchart

User reports bug with external service
  │
  ├─ Is there a try/catch swallowing the error?
  │   └─ YES → Temporarily log the full error BEFORE guessing
  │
  ├─ Does the API return success but side-effect is missing?
  │   └─ YES → FETCH DOCS FIRST. Do NOT guess the cause.
  │            Compare exact parameter shapes, types, and values
  │            against what the docs specify.
  │
  └─ Is the error a 4xx?
      └─ YES → FETCH DOCS. Check which parameters are valid
               for the current SDK version.

Bundled Resources

scripts/check_versions.py

Automated version checker for npm and pip packages. Run it to quickly identify outdated dependencies:

# Check a single npm package
python3 scripts/check_versions.py npm resend
# Check all package.json dependencies
python3 scripts/check_versions.py npm --all
# Check a pip package
python3 scripts/check_versions.py pip requests

references/doc-urls.md

Quick-reference table of official API documentation and changelog URLs for 30+ popular packages (email, payments, AI, databases, auth, cloud, analytics, frameworks). Consult this before searching — the correct URL may already be listed.

Related Skills

• dependency-management — use alongside when resolving version conflicts or managing lockfiles
• third-party-integration — use alongside when implementing the actual integration patterns after verifying docs
• api-versioning-strategy — use when designing your own API's versioning, not checking upstream