fix(s3): support get-object region override and robust S3 URL parsing

[waleedlatif1]

Summary

• add a dedicated optional region input for S3 get-object in the block UI
• align block/tool params so get-object uses URL region, optional override, then fallback
• harden S3 URL parsing to support virtual-hosted, path-style, dualstack, legacy, dotted buckets, and aws-cn hosts

Type of Change

• Bug fix

Testing

Tested manually

Checklist

• Code follows project style guidelines
• Self-reviewed my changes
• Tests added/updated and passing
• No new warnings introduced
• I confirm that I have read and agree to the terms outlined in the Contributor License Agreement (CLA)

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1 Skipped Deployment

Project	Deployment	Actions	Updated (UTC)
docs	Skipped		Feb 12, 2026 8:43am

[greptile-apps]

Greptile Overview

Greptile Summary

This PR enhances S3 get-object functionality with robust URL parsing and region handling. The changes add a dedicated optional region input field in the block UI and implement comprehensive S3 URL parsing that supports multiple URL formats including virtual-hosted style, path-style, dualstack, legacy formats, bucket names with dots, and AWS China (.cn) domains.

Key improvements:

• Added getObjectRegion field to S3 block UI for optional region override when downloading objects
• Implemented hierarchical region resolution: URL-embedded region → user-provided override → default us-east-1
• Enhanced parseS3Uri to handle diverse S3 URL formats with proper regex patterns for hostname parsing
• Simplified block-level parameter logic by delegating URL parsing to the tool layer
• Added defensive error handling for malformed URL encoding in object keys

The implementation correctly prioritizes region sources and maintains backward compatibility. The regex patterns properly handle edge cases like bucket names containing dots.

Confidence Score: 4/5

• This PR is safe to merge with minor considerations
• The implementation is well-structured with comprehensive URL format support and proper error handling. The hierarchical region resolution logic is sound. However, the PR lacks automated tests to verify the regex patterns work correctly for all supported URL formats (virtual-hosted, path-style, dualstack, dotted buckets, AWS China). Manual testing was performed but test coverage would increase confidence in edge case handling.
• No files require special attention - the changes are well-isolated to S3 functionality

Important Files Changed

Filename	Overview
apps/sim/tools/s3/utils.ts	Enhanced S3 URL parsing to support virtual-hosted, path-style, dualstack, and AWS China URLs with optional region fallback
apps/sim/tools/s3/get_object.ts	Added optional region parameter that passes through to parseS3Uri for region override functionality
apps/sim/blocks/blocks/s3.ts	Added dedicated getObjectRegion UI field and simplified get_object params logic to delegate URL parsing to tool layer

Sequence Diagram

sequenceDiagram
    participant User
    participant S3Block
    participant S3GetObjectTool
    participant parseS3Uri
    participant S3Service

    User->>S3Block: Provides S3 URL & optional region override
    S3Block->>S3Block: Validates inputs (accessKeyId, secretAccessKey, s3Uri)
    S3Block->>S3GetObjectTool: Passes credentials, s3Uri, region (getObjectRegion || region)
    S3GetObjectTool->>parseS3Uri: parseS3Uri(s3Uri, region)
    parseS3Uri->>parseS3Uri: Try URL hostname region extraction
    parseS3Uri->>parseS3Uri: Supports virtual-hosted & path-style URLs
    parseS3Uri->>parseS3Uri: Priority: URL region > fallback region > us-east-1
    parseS3Uri-->>S3GetObjectTool: Returns {bucketName, region, objectKey}
    S3GetObjectTool->>S3GetObjectTool: Builds request URL with parsed values
    S3GetObjectTool->>S3GetObjectTool: Generates AWS Signature V4 headers
    S3GetObjectTool->>S3Service: GET request with signed headers
    S3Service-->>S3GetObjectTool: Returns object data
    S3GetObjectTool->>S3GetObjectTool: Generates pre-signed URL
    S3GetObjectTool-->>User: Returns file data & pre-signed URL

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[waleedlatif1]

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