Install & Compatibility
Where this runs
tested against v1.43.76 · pip install
no network on importno background threads
Install × environment matrix
Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux
muslpy 3.10–3.95 runs
installs and imports cleanly · install 0.0s · import 0.692s · 52.4MB
glibcpy 3.10–3.95 runs
installs and imports cleanly · install 4.0s · import 0.636s · 53MB
51MB installed
● package 51MB
Code
Verified usage
Verified import paths — ran on the pinned version, not inferred.
LambdaClient
✓ from mypy_boto3_lambda.client import LambdaClient
Used for explicit type hinting of the Lambda client object.
ListFunctionsResponseTypeDef
✓ from mypy_boto3_lambda.type_defs import ListFunctionsResponseTypeDef
Used for explicit type hinting of method response objects.
This example demonstrates how to create a type-hinted `boto3` Lambda client. `mypy` will automatically pick up the installed stubs when `boto3.client('lambda')` is called, providing autocompletion and type validation. Explicit imports for `LambdaClient` and response `TypeDef` are used for clearer annotations.
import boto3
from mypy_boto3_lambda.client import LambdaClient
from mypy_boto3_lambda.type_defs import ListFunctionsResponseTypeDef
# Create a typed Lambda client
# mypy will automatically use the installed mypy-boto3-lambda stubs for type checking
lambda_client: LambdaClient = boto3.client("lambda")
try:
# Example: List Lambda functions
# The response object will be correctly typed
response: ListFunctionsResponseTypeDef = lambda_client.list_functions(MaxItems=1)
print("Successfully listed Lambda functions (first item): ")
for func in response.get("Functions", []):
print(f"- {func['FunctionName']}")
except Exception as e:
# This may happen if AWS credentials are not configured or if the user lacks permissions.
print(f"Error listing Lambda functions: {e}")
print("Ensure your AWS credentials are configured (e.g., via AWS CLI or environment variables).")
Debug
Known issues
breakingSupport for Python 3.8 was removed. Packages generated by `mypy-boto3-builder` v8.12.0 and later (which includes `mypy-boto3-lambda` v1.42.85) require Python 3.9 or higher.fixUpgrade your Python environment to 3.9 or newer. If you must use Python 3.8, you'll need to pin to older `mypy-boto3-lambda` versions, though this is not recommended due to potential `boto3` mismatches.
affects: Packages generated by `mypy-boto3-builder` v8.12.0+
breakingThe `sms-voice` service was deprecated and renamed to `pinpoint-sms-voice`. Direct usage of the `sms-voice` client will fail.fixUpdate your code to use `boto3.client("pinpoint-sms-voice")` instead of `boto3.client("sms-voice")`. affects: Packages generated by `mypy-boto3-builder` v8.11.0+
breakingTypeDef names for packed method arguments changed, becoming shorter (e.g., `CreateDistributionRequestRequestTypeDef` -> `CreateDistributionRequestTypeDef`). Conflicting TypeDef `Extra` postfixes also moved.fixReview and update explicit TypeDef annotations in your code to match the new naming conventions, or rely on implicit typing where possible and let `mypy` infer the correct types.
affects: Packages generated by `mypy-boto3-builder` v8.9.0+
gotchaThis package provides only type stubs. It is not the `boto3` library itself. You must install `boto3` separately for your code to function at runtime.fixEnsure `boto3` is included in your project's dependencies: `pip install boto3 mypy-boto3-lambda`.
affects: All versions
gotchaThe `mypy-boto3-*` stub packages are versioned to align with specific `boto3` versions. Using mismatched versions (e.g., `mypy-boto3-lambda` 1.42.85 with `boto3` 1.20.0) can lead to incorrect type hints or `mypy` errors.fixAlways try to keep your `mypy-boto3-*` stub versions as close as possible to your `boto3` version. The recommended approach is to install the latest versions of both.
affects: All versions
breaking`boto3` requires an AWS region to be configured. Without a specified region, client initialization will fail.fixConfigure an AWS region via environment variables (e.g., `AWS_REGION`), AWS shared configuration files (e.g., `~/.aws/config`), or by passing `region_name` directly to `boto3.client()` (e.g., `boto3.client('lambda', region_name='us-east-1')`). affects: All versions
breakingBoto3 clients require an AWS region to be explicitly configured or available through environment variables/configuration files. Without a region, service client initialization will fail.fixEnsure an AWS region is configured either by passing `region_name='your-region'` to `boto3.client()`, setting the `AWS_DEFAULT_REGION` environment variable, or configuring it in `~/.aws/config`.
affects: All versions
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Version history
1.43.76latest on PyPI · released Aug 20, 2026
Audit
Dependencies
boto3requiredThis package provides type stubs for `boto3`. `boto3` itself must be installed to use the Lambda client functionality at runtime.