---
id: aws-cdk-cx-api
version: "2.265.0"
license: Apache-2.0
license_treatment: permissive
maintenance: active
---

# aws-cdk.cx-api — Cloud executable protocol

License: permissive · Maintenance: active · Downloads: 203.8K/mo

## What it is and what it does

aws-cdk.cx-api is the protocol layer and context API that underpins the AWS Cloud Development Kit. It defines how CDK synthesizes infrastructure code into cloud assembly artifacts—the intermediate representation that gets deployed to CloudFormation and other AWS services. The package handles serialization of CDK constructs, manages feature flags that control CDK behavior across versions, and provides the runtime context needed for CDK applications to generate correct CloudFormation templates.

This is a low-level component primarily consumed by other CDK modules rather than directly by application code. It depends on jsii for language bindings, cloud-assembly-schema for artifact structure, and publication for distribution. The package is actively maintained as part of the AWS CDK project and supports Python 3.10 through 3.14.

Use it for:

- Building custom CDK constructs or extensions that need to interact with the cloud assembly protocol.
- Configuring CDK feature flags in cdk.json to control S3 bucket policies, SNS-SQS security, API Gateway CloudWatch roles, and other infrastructure behaviors.
- Integrating CDK-generated infrastructure with custom deployment or validation tooling that consumes cloud assembly artifacts.
- Debugging CDK synthesis by accessing the context API and cloud executable format directly.

## Worth the install?

AI-flagged interpretation of the facts above — verify before relying.

Provides the cloud executable protocol and context API for AWS CDK, enabling the CDK to serialize and communicate infrastructure definitions to CloudFormation and other deployment targets.

Yes, but typically as a transitive dependency rather than a direct install. If you are building AWS CDK applications in Python, this package will be installed automatically. Install it directly only if you are extending CDK with custom constructs, building tooling around CDK synthesis, or need to configure advanced feature flags for your infrastructure code.

## Install

pip install aws-cdk-cx-api
uv add aws-cdk-cx-api
poetry add aws-cdk-cx-api

## Installing aws-cdk.cx-api

Before you install: Active maintenance with a release 1 day old. Low install friction with only 3 runtime dependencies. Part of the core AWS CDK ecosystem with strong repository signals (12868 stars, current commits).

License in practice: Licensed under Apache-2.0 (permissive), allowing free use, modification, and distribution with minimal restrictions—standard for AWS CDK components.

Quickstart:

pip install aws-cdk.cx-api

from aws_cdk.cloud_assembly_schema import CloudAssembly
from aws_cdk.cx_api import CloudAssemblyBuilder

builder = CloudAssemblyBuilder()
# Use builder to construct cloud assembly artifacts

Requires Python 3.10 or later; intended as an internal AWS CDK component, not typically installed directly by end users.

Verify before relying:

- Whether this package is intended for direct use or primarily as an internal CDK dependency.
- Specific use cases and APIs beyond feature flag configuration documented in the excerpt.

## Package facts

- License: Apache-2.0 (permissive)
- Python support: supports_current
- Install friction: low
- Maintenance: active
- Downloads: 203.8K/month (top 15,000 on PyPI)
- Known vulnerabilities: none known

## Tags

AWS CDK cloud assembly, CDK context API, infrastructure serialization, CDK protocol layer, cloud executable format, CDK deployment protocol, AWS infrastructure as code runtime, aws-cdk, infrastructure-as-code, cloudformation

[View on SkillFed](https://skillfed.io/packages/aws-cdk-cx-api) · [View on PyPI](https://pypi.org/project/aws-cdk-cx-api/)