AWS SDK Knowledge Patch Skill

AWS SDK Knowledge Patch

Covers AWS SDK changes from 2024-12 through 2026-03. Applies to JS v3 ~3.600+, boto3 ~1.34+, aws-sdk-go-v2 ~1.26+, CDK v2 ~2.140+.

Index

| Topic | Reference | Key features | |---|---|---| | S3 checksums & vectors | references/s3-checksums-and-vectors.md | Default CRC checksums, CRC64NVME, full-object multipart checksums, S3 Vectors service | | Lambda Durable Functions | references/lambda-durable-functions.md | Checkpoint-and-replay, @durable_step, wait/callback, idempotency | | Bedrock AgentCore | references/bedrock-agentcore.md | Runtime deployment, memory client, identity/OAuth2, CLI | | CDK & SDK config | references/cdk-and-sdk-config.md | CDK Mixins .with(), SigV4a auth scheme preference, STS regional default, SDK lifecycle |

S3 Default Checksums (Dec 2024) — Breaking Change

SDKs now compute CRC checksums on every upload by default. S3 also computes server-side checksums on all uploads.

New algorithm: CRC64NVME. Default algorithms vary by SDK:

| SDK | Default algorithm | |---|---| | CLI, C++, Rust | CRC64NVME | | Go, Java, JS, Kotlin, .NET, PHP, Python, Ruby | CRC32 |

Config settings:

| Setting | Env var | Default | |---|---|---| | request_checksum_calculation | AWS_REQUEST_CHECKSUM_CALCULATION | WHEN_SUPPORTED | | response_checksum_validation | AWS_RESPONSE_CHECKSUM_VALIDATION | WHEN_SUPPORTED |

Multipart uploads now support ChecksumType='FULL_OBJECT' for a single whole-object checksum instead of per-part composites.

See references/s3-checksums-and-vectors.md for full examples.

S3 Vectors (GA Dec 2025)

New S3 service for storing/querying vector embeddings. Separate from regular S3 buckets.

aws s3vectors create-vector-bucket --vector-bucket-name my-vectors
aws s3vectors create-index \
    --vector-bucket-name my-vectors \
    --index-name my-index \
    --data-type float32 --dimension 1024 \
    --distance-metric cosine \
    --metadata-configuration "nonFilterableMetadataKeys=text_chunk"

Supports cosine and euclidean distance. Up to 2B vectors/index, 50 metadata keys/vector (10 non-filterable). Integrates with Bedrock Knowledge Bases and OpenSearch.

See references/s3-checksums-and-vectors.md for query examples.

Lambda Durable Functions (Dec 2025)

Checkpoint-and-replay execution for Lambda. Must be enabled at function creation time (cannot be added later). Open-source SDK.

from aws_durable_execution_sdk_python import (
    DurableContext, StepContext, durable_execution, durable_step,
)
from aws_durable_execution_sdk_python.config import Duration, StepConfig, CallbackConfig

@durable_step
def my_step(step_context: StepContext, data: str) -> dict:
    return {"result": data}

@durable_execution
def lambda_handler(event: dict, context: DurableContext) -> dict:
    result = context.step(my_step(event["data"]))
    context.wait(Duration.from_minutes(5))  # suspends without compute charges
    return result

Supports JS/TS (Node.js 22/24) and Python (3.13/3.14). See references/lambda-durable-functions.md for callbacks and retry strategies.

Bedrock AgentCore (GA Oct 2025)

Enterprise services for deploying AI agents at scale. Framework-agnostic (Strands, LangGraph, etc.).

from bedrock_agentcore.runtime import BedrockAgentCoreApp
app = BedrockAgentCoreApp()

@app.entrypoint
def invoke(payload):
    return agent(payload.get("prompt"))

Install: pip install bedrock-agentcore bedrock-agentcore-starter-toolkit CLI: agentcore configure, agentcore launch [--local], agentcore invoke.

See references/bedrock-agentcore.md for memory client, identity, and full API.

CDK Mixins (GA Mar 2026)

Composable, reusable abstractions for any CDK construct via .with() syntax:

const bucket = new s3.CfnBucket(this, 'Bucket').with(
  AutoDelete(),
  Encryption(),
  Versioning(),
  BlockPublicAccess(),
);
// Apply compliance policies across a scope:
Mixins.of(this).add(/* resource type or path pattern filtering */);

See references/cdk-and-sdk-config.md for details.

Auth Scheme Preference (SigV4a)

New config for cross-region signing (e.g., multi-region access points):

# ~/.aws/config
[default]
auth_scheme_preference = sigv4a, sigv4
sigv4a_signing_region_set = us-east-1, eu-west-1

Env vars: AWS_AUTH_SCHEME_PREFERENCE, AWS_SIGV4A_SIGNING_REGION_SET.

SDK Version Lifecycle

| SDK | Maintenance | End of Support | Migrate To | |---|---|---|---| | JS v2 | Sep 2024 | Sep 2025 | JS v3 | | Go v1 | Jul 2024 | Jul 2025 | Go v2 | | .NET v3 | Mar 2026 | Jun 2026 | .NET v4 (GA Apr 2025) |

JS v3 Node.js: Follows Node.js release + 8 months. Node.js 18 dropped Jan 2026 (requires 20+). Node.js 20 drops Jan 2027.

Python (boto3): 6-month grace after PSF EOL. Python 3.9 drops Apr 2026, 3.10 drops Apr 2027.

SDK Default Changes (July 2025)

STS endpoint: Python, PHP, C++, .NET, PowerShell switch to regional default (was global)
Retry strategy: Switch to standard (token-bucket throttling) delayed — AWS found concerns, will reschedule

Reference Files

| File | Contents | |---|---| | s3-checksums-and-vectors.md | Default checksums, CRC64NVME, multipart full-object checksums, S3 Vectors API | | lambda-durable-functions.md | Durable execution SDK, steps, wait/callback, retry strategies | | bedrock-agentcore.md | Runtime deployment, memory client, identity, CLI commands | | cdk-and-sdk-config.md | CDK Mixins, SigV4a, STS regional default, SDK lifecycle dates |

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