NewYour coding agent can read the release notes before it upgrades.Set up the MCP server →
PyPI · #2473 most downloaded on PyPI
AWS Lambda Runtime Interface Client for Python
Last release 6 days ago
28 Sep 2026
Release timing varies
gaps range from 8 days to 9 months
Most releases are documented
notes for 26 of 33 stable releases
Nothing withdrawn
no release was ever pulled
6 years old
33 releases · first in 2020
One column per quarter.
Add pre-fork hooks for multi-concurrent (Lambda Managed Instances) mode. A function can register callables with the @register_pre_fork decorator from
@register_pre_fork decorator from awslambdaric.lambda_concurrency_hooks; they run once in the parent process, after the handler is imported and before worker processes are started. Workers re-import the handler in their own process, so hooks are for external side effects (starting a subprocess, warming a local service, writing to /tmp) and share no in-memory state with workers. A hook that raises is reported to the Runtime API as an INIT error with the type Runtime.PreForkError and no worker is started. No impact on the standard on-demand path.Use the level key (instead of log_level ) for the log level field in JSON-formatted uncaught error logs, aligning it with the key used by other struct
level key (instead of log_level) for the log level field in JSON-formatted uncaught error logs, aligning it with the key used by other structured log events (#221)Emit a structured runtime_worker_pool_initializing DEBUG log event once per execution environment during INIT in multi-concurrent (Lambda Managed Inst
runtime_worker_pool_initializing DEBUG log event once per execution environment during INIT in multi-concurrent (Lambda Managed Instances) mode, reporting workerCount and executionEnvironmentMaxConcurrency for worker pool observability. Only visible when the function log level is DEBUG or lower; no impact on the standard on-demand path.Add Lambda-Runtime-Invocation-Id header support for cross-wiring protection. The RIC now echoes the invocation ID received from RAPID on /next back on
Lambda-Runtime-Invocation-Id header support for cross-wiring protection. The RIC now echoes the invocation ID received from RAPID on /next back on /response and /error, enabling RAPID to detect and reject stale responses from timed-out invocations.Support building on Alpine Linux 3.17+ (musl) without libexecinfo-dev
Nothing published for this version
Move unhandled exception warning message to init errors. by @briensea in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/189
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/3.1.0...3.1.1
Full Changelog: 3.1.0...3.1.1
feat: add tenant-id to lambda context and structured log message by @ramisa2108 in https://github.com/aws/aws-lambda-python-runtime-interface-client/p
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/3.0.2...3.1.0
Full Changelog: 3.0.2...3.1.0
Update simplejson to 3.20.1 by @briensea in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/184
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/3.0.1...3.0.2
Don't enforce text format on uncaught exception warning message by @dtorok in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/1
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/3.0.0...3.0.1
Full Changelog: 3.0.0...3.0.1
Dropped Support: Deprecated Python runtimes below 3.9 are no longer supported.
Update version to 2.2.1 by @m-rph in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/170
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.1.1...2.2.1
Full Changelog: 2.1.1...2.2.1
Nothing published for this version
Use latest codebuild version by @m-rph in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/157
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.12...2.1.0
Full Changelog: 2.0.12...2.1.0
Fix alpine image breaking due to missing dependencies and curl by @m-rph in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/146
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.11...2.0.12
Upgrade simplejson to 3.18.4 by @kpark-hrp in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/136
3.18.4 by @kpark-hrp in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/136Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.10...2.0.11
Update format of unhandled exception warning message. by @briensea in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/132
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.9...2.0.10
Log warning on unhandled exception. by @briensea in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/120
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.8...2.0.9
Fix runtime_client blocking main thread from SIGTERM being handled. Enabled by default only for Python3.12 (#115) by @tgsong (#124) by @pushkarchawda
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.7...2.0.8
Use AWS_LAMBDA_LOG_LEVEL env var to set log level for text format by @kotyara1005 in https://github.com/aws/aws-lambda-python-runtime-interface-client
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.6...2.0.7
Emit logs in JSON format by @kotyara1005 in https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/101
Full Changelog: https://github.com/aws/aws-lambda-python-runtime-interface-client/compare/2.0.5...2.0.6
Emit multi-line logs with timestamps.
Nothing published for this version
Nothing published for this version
Nothing published for this version
Nothing published for this version
AWS Lambda Runtime Interface Client for Python with ARM64 support
AWS Lambda Runtime Interface Client for Python with ARM64 support
Remove importlib.metadata dependency & introduce \__version__ #55
Nothing published for this version
Add Support for / in handler name #45
- Update Curl version to 7.77.0
Replace usage of deprecated module imp with importlib
Release GIL (Global Interpreter Lock) while polling runtime/invocation/next (https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/33)
Replace usage of deprecated module imp with importlib (https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/28)
Ensure that errorMessage, errorType, and stackTrace are always part of error responses (https://github.com/aws/aws-lambda-python-runtime-interface-client/pull/15)
Initial release of AWS Lambda Runtime Interface Client for Python
Initial release of AWS Lambda Runtime Interface Client for Python
Your coding agent can read these notes before it upgrades. Set up the MCP server →