aws-ref : AWS IAM Service Reference Helper CLI

A powerful CLI tool designed for AWS Cloud Engineers to explore IAM actions and understand their condition key support - perfect for writing CloudFormation templates and IAM policies!

Problem It Solves

As an AWS Cloud Engineer, you know the pain of:

• Not knowing which IAM actions support aws:RequestTag/${TagKey}
• Being unsure if aws:ResourceTag/${TagKey} works with a specific action
• Wondering if aws:TagKeys condition is supported
• Trying to figure out which actions support aws:SourceArn conditions
• Debugging CloudFormation templates due to invalid condition keys

aws-ref solves all of this by providing instant, human-readable information about every IAM action across all AWS services!

Features

• Search Actions: Find IAM actions for any AWS service
• Tag Support Detection: Instantly see if an action supports RequestTag, ResourceTag, or TagKeys
• ARN Conditions: Check for SourceArn and SourceAccount support
• Policy Generation: Generate example IAM policies with condition keys
• Complete Coverage: Access data for all AWS services
• Fast: Direct API calls to AWS Service Reference

Installation

Using pip (Recommended)

pip3 install aws-ref

From Source

git clone https://github.com/yourusername/aws-ref.git
cd aws-ref
pip3 install -e .

Quick Start

List All AWS Services

aws-ref --list

Explore All S3 Actions

aws-ref s3

Search for Specific Action

aws-ref s3 -a PutObject

Verbose Mode (Show All Condition Keys)

aws-ref s3 -a PutObject -v

Generate Example IAM Policy

aws-ref s3 -a PutObject --policy

Usage Examples

Example 1: Check Tag Support for S3 PutObject

$ aws-ref s3 -a PutObject

================================================================================
Action: PutObject
================================================================================

Properties:
  • Is Write:       ✓ Yes
  • Is Read:        ✗ No
  • Is List:        ✗ No
  • Is Tagging:     ✗ No
  • Is Permission:  ✗ No

Resource Types: 2
  • accesspointobject
  • object

Condition Key Support:
  Total Keys: 21

  Tag-Based Conditions:
    • RequestTag/*:  ✓ Supported (2 keys)
    • ResourceTag/*: ✗ Not Supported
    • TagKeys:       ✓ Supported

  ARN-Based Conditions:
    • Source ARN:    ✗ Not Supported
    • Source Acct:   ✗ Not Supported

  Other Condition Keys (19):
    (use -v to see all 19 keys)

Example 2: Generate Policy with Condition Keys

$ aws-ref s3 -a PutObject --policy

Example IAM Policy:

Service: s3
Action: PutObject

Supported Resource Types:
  • accesspointobject
  • object

Policy JSON:
{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "s3:PutObject",
      "Resource": "*",
      "Condition": {
        "StringEquals": {
          "aws:RequestTag/Environment": "production"
        },
        "ForAllValues:StringEquals": {
          "aws:TagKeys": [
            "Environment",
            "Owner"
          ]
        }
      }
    }
  ]
}

Example 3: Search Multiple Actions

aws-ref ec2 -a Describe

This will show all EC2 actions containing "Describe" in their name.

Example 4: Check Lambda Function Tagging

aws-ref lambda -a TagResource -v

Output Information

For each action, the tool displays:

Properties

• Is Write: Whether the action modifies resources
• Is Read: Whether the action only reads data
• Is List: Whether the action lists resources
• Is Tagging: Whether the action is tagging-only
• Is Permission: Whether the action manages permissions

Tag-Based Conditions

• RequestTag/*: Conditions on tags in the request (e.g., during resource creation)
• ResourceTag/*: Conditions on existing resource tags
• TagKeys: Conditions on which tag keys are present

ARN-Based Conditions

• Source ARN: Whether action supports source ARN conditions
• Source Account: Whether action supports source account conditions

Other Information

• Resource Types: What resource types the action can operate on
• All Condition Keys: Complete list of supported condition keys (with -v)
• IAM Support: Whether supported by IAM Access Analyzer and Action Last Accessed

Common Use Cases

Writing CloudFormation IAM Policies

# Check what condition keys are available for your action
aws-ref dynamodb -a PutItem -v

# Generate a policy template
aws-ref dynamodb -a PutItem --policy

Debugging "Invalid Condition Key" Errors

# Verify if a condition key is actually supported
aws-ref s3 -a GetObject -v | grep -i "source"

Understanding Tag-Based Access Control

# See which actions support tag conditions
aws-ref ec2 -a CreateInstance -v

Exploring Service Permissions

# List all available services
aws-ref --list

# Explore a specific service
aws-ref secretsmanager

Command-Line Options

usage: aws-ref [-h] [-a ACTION] [-v] [-l] [-p] [--no-color] [service]

AWS IAM Explorer - Explore IAM actions and their condition key support

positional arguments:
  service               AWS service name (e.g., s3, ec2, lambda)

optional arguments:
  -h, --help            show this help message and exit
  -a ACTION, --action ACTION
                        Filter by action name (supports partial matching)
  -v, --verbose         Show all condition keys in detail
  -l, --list            List all available AWS services
  -p, --policy          Generate example IAM policy for the action
  --no-color            Disable colored output

Data Source

This tool uses the official AWS Service Authorization Reference API:

• Base URL: https://servicereference.us-east-1.amazonaws.com/
• Always up-to-date with the latest AWS services and actions
• No AWS credentials required!

Acknowledgments

• AWS Service Authorization Reference for providing the data API
• All AWS Cloud Engineers struggling with IAM policies (I feel your pain! : D)