feat: add seedream-4.5 model for ByteDance image generation

[Kamilbenkirane]

Summary

Adds the new Seedream 4.5 model (seedream-4-5-251128) to the ByteDance image generation provider.

Changes

• Added seedream-4-5-251128 model with appropriate parameter constraints:
  • Aspect ratio: 2560x1440 to 4096x4096 pixels
  • Quality options: 2K, 4K
  • Watermark support
  • Multiple preset aspect ratios

Model Details

• Model ID: seedream-4-5-251128
• Display Name: Seedream 4.5
• Provider: ByteDance
• Release Date: December 2025 (v25.12)

Validation

• Model ID validated against official BytePlus API documentation
• Parameter constraints verified against API specifications

[claude]

Code Review: Add Seedream 4.5 Model

Overall Assessment

LGTM with minor suggestions - This is a clean, straightforward model addition that follows the established patterns in the codebase.

Code Quality & Best Practices

Strengths:

• Follows the established pattern used in seedream-4-0-250828
• Consistent code style with proper formatting and inline comments
• Uses the same import structure and constraint classes as other models
• Parameter constraints are well-defined

Code Structure:
The model definition at packages/image-generation/src/celeste_image_generation/providers/bytedance/models.py:34-58 is well-structured.

Potential Issues & Concerns

1. Preset Validation Concern

Some presets may not satisfy the min_pixels constraint (2560 * 1440 = 3,686,400):

• HD 16:9 (1920x1080) has 2,073,600 pixels - BELOW minimum
• Portrait HD (1080x1920) has 2,073,600 pixels - BELOW minimum

Impact: Users selecting these presets will get ConstraintViolationError at runtime (see constraints.py:52-57).

Recommendation: Either remove presets that don't meet minimum, adjust min_pixels, or verify BytePlus API docs.

2. Quality Options Differ from Seedream 4.0

• Seedream 4.0 supports: [1K, 2K, 4K]
• Seedream 4.5 supports: [2K, 4K]

Is dropping 1K support intentional? Should verify against BytePlus API documentation.

Performance Considerations

No performance concerns. Static data with no runtime overhead.

Security Concerns

No security issues identified. Uses proper type constraints for validation.

Test Coverage

Missing: No test coverage for the new model in integration tests.

Recommendation: Add test case to packages/image-generation/tests/integration_tests/test_image_generation/test_generate.py:
(Provider.BYTEDANCE, seedream-4-5-251128, {aspect_ratio: 2560x1440})

Action Items

High Priority:

1. Verify and fix preset dimensions that violate min_pixels constraint
2. Confirm quality options with BytePlus API docs

Medium Priority:
3. Add integration test coverage for the new model

Conclusion

Solid work overall! Main concern is potential runtime error from invalid presets. Once verified/fixed, ready to merge!

[claude]

Pull Request Review: Add Seedream 4.5 Model

Summary

This PR adds the new Seedream 4.5 model to the ByteDance image generation provider. The implementation follows the established patterns in the codebase and is well-structured.

✅ Code Quality & Best Practices

Strengths:

• ✅ Follows the existing code structure and conventions perfectly
• ✅ Consistent with Seedream 4.0 model definition pattern
• ✅ Proper use of Dimensions constraint with min/max pixels and aspect ratios
• ✅ Clear inline comments for pixel calculations (e.g., # 3,686,400)
• ✅ Appropriate use of preset aspect ratios matching existing patterns
• ✅ Clean, readable code with proper formatting

🔍 Technical Analysis

Model Configuration

The new model definition at models.py:34-58 includes:

• ID: seedream-4-5-251128 (follows naming convention)
• Display Name: "Seedream 4.5"
• Dimensions: 2560x1440 to 4096x4096 pixels (higher minimum than 4.0)
• Quality Options: ["2K", "4K"] (note: removed "1K" option from 4.0)
• Aspect Ratios: Same presets as 4.0 (good consistency)

Comparison with Seedream 4.0

Feature	4.0	4.5
Min Pixels	921,600 (1280x720)	3,686,400 (2560x1440)
Max Pixels	16,777,216 (4096x4096)	16,777,216 (4096x4096)
Quality Options	1K, 2K, 4K	2K, 4K

The higher minimum resolution makes sense for a newer model generation.

⚠️ Potential Issues

1. Preset Validation Concern (Low Priority)

Some presets in lines 47-51 fall below the minimum pixel threshold:

• "HD 16:9": "1920x1080" → 2,073,600 pixels (below 3,686,400 minimum)
• "Portrait HD": "1080x1920" → 2,073,600 pixels (below minimum)

Impact: If users try to use these presets, they will fail validation in the Dimensions constraint at constraints.py:52.

Recommendation: Either:

• Remove these presets for Seedream 4.5, or
• Update them to meet the minimum (e.g., "2K 16:9" as the minimum 16:9 option)

2. PR Description Date Accuracy

The PR description mentions "Release Date: December 2025 (v25.12)" but today is December 11, 2025. This might be:

• A typo (should be November 2025 based on model ID 251128)
• Or accurate if it's a pre-release

Recommendation: Verify the actual release date matches the model ID suffix 251128 (November 28, 2025).

🔒 Security

• ✅ No security concerns identified
• ✅ Proper input validation through Dimensions constraint
• ✅ No hardcoded credentials or sensitive data
• ✅ Uses existing secure ByteDance provider infrastructure

🚀 Performance

• ✅ No performance concerns
• ✅ Static configuration with no runtime overhead
• ✅ Efficient constraint validation using existing Dimensions class

🧪 Test Coverage

Missing Test Coverage

The integration test at test_generate.py:14 only tests Seedream 4.0.

Recommendation: Consider adding a test case for Seedream 4.5

Note: Since this is adding a new model to an existing provider with the same parameter structure, and the framework handles model registration automatically, comprehensive testing may not be critical. However, it would ensure the model is properly registered and functional.

📋 Recommendations

Priority 1: Fix Preset Validation

Update or remove HD presets that fall below the minimum pixel threshold.

Priority 2: Verify Release Date

Confirm the release date in the PR description matches the model ID.

Priority 3: Consider Integration Test

Add an integration test case for Seedream 4.5 to ensure the model is properly registered and functional.

✨ Overall Assessment

This is a well-implemented PR that follows all established conventions. The code quality is excellent, and the changes are minimal and focused. The only issues are minor validation inconsistencies with the presets that should be addressed before merging.

Recommendation: ✅ Approve with minor fixes for the preset validation issue.

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Review generated with assistance from Claude Code