Genkit Python SDK v0.5.0

Release: Genkit Python SDK v0.5.0

Overview

This is a major release of the Genkit Python SDK with 178 commits and 680 files changed over 8 months since v0.4.0 (May 2025). This release represents the most significant update to the Python SDK to date, adding extensive new model providers, telemetry integrations, core framework features, and substantial improvements to type safety and developer experience.

Impact Summary

Category	Impact	Migration Required
New Model Plugins	🟢 High - 7 new providers	No (additive)
New Telemetry Plugins	🟢 High - 3 new providers	No (additive)
Core Features	🟢 High - rerankers, Dotprompt, tool calling	No (additive)
PluginV2 Refactor	🟡 Medium	Yes - plugin authors
Async-First Architecture	🟡 Medium	Yes - if using sync APIs
Type Safety	🟢 High	No (stricter checks)
Security Enhancements	🟢 High	No (automatic)
Python 3.14 Support	🟢 High	No (additive)
Performance	🟢 High	No (automatic)

What's New

New Model Provider Plugins (7)

Plugin	Provider	Key Features
genkit-plugin-anthropic	Anthropic	Claude models (Opus, Sonnet, Haiku)
genkit-plugin-aws-bedrock	AWS Bedrock	Claude, Titan, Llama via AWS
genkit-plugin-msfoundry	Azure OpenAI	Microsoft Foundry integration
genkit-plugin-cf-ai	Cloudflare	Workers AI models
genkit-plugin-deepseek	DeepSeek	DeepSeek models with structured output
genkit-plugin-xai	xAI	Grok models
genkit-plugin-mistral	Mistral AI	Large, Small, Codestral, Pixtral
genkit-plugin-huggingface	Hugging Face	17+ inference providers

New Telemetry Plugins (3)

Plugin	Provider	Key Features
genkit-plugin-aws	AWS X-Ray	SigV4 signing, OTLP export
genkit-plugin-observability	Third-party	Sentry, Honeycomb, Datadog
genkit-plugin-google-cloud	GCP	Full parity with JS/Go SDKs

Core Framework Features

• Agentive Tool Calling: Define tools with @ai.tool() decorator for AI agents
• Rerankers: Initial reranker implementation for RAG pipelines
• Background Models: Dynamic model discovery and background action support
• Evaluator Metrics: ANSWER_RELEVANCY, FAITHFULNESS, MALICIOUSNESS
• Output Formats: Array, enum, JSONL formats (JS SDK parity)
• Pydantic Output: Return typed Pydantic instances from generation

Dotprompt Integration (via google/dotprompt)

• Dotpromptz 0.1.5: Latest version with type-safe schema fields
• Python 3.14 Support: PyO3/maturin ABI compatibility for Rust-based Handlebars engine
• Directory/File Prompt Loading: Automatic prompt discovery matching JS SDK
• Handlebars Partials: define_partial for template reuse
• Render Methods: render_system_prompt and render_user_prompt
• Callable Support: Prompts can be used directly as callables
• Security: Cycle detection prevents infinite recursion, path traversal hardening (CWE-22)
• Helper Parity: Consistent Handlebars helper behavior across all runtimes
• Release Pipeline: Automated PyPI publishing, release time reduced from 30 min to 2 min

Breaking Changes

1. PluginV2 Refactor (#4132)

Impact: Plugin authors need to update their plugins.

Before:

class MyPlugin(Plugin):
    def __init__(self, config):
        self.config = config

After:

class MyPlugin(PluginV2):
    def __init__(self, config):
        super().__init__(config)
        # Use standardized registration pattern

2. Async-First Architecture (#4244)

Impact: Sync base classes removed. All operations are now async.

Before:

result = flow.run_sync(input)  # No longer available

After:

result = await flow.run(input)  # Use async/await
# Or use asyncio.run() at entry points

3. Embed API Refactor (#4269)

Impact: embed/embed_many API updated for JS parity.

Before:

# Old API signature

After:

# New API matches JS SDK patterns

Type Safety Improvements

This release integrates three type checkers for comprehensive coverage:

• ty (Astral/Ruff): Fast, strict checking - 0 errors
• pyrefly (Meta): Additional coverage - 0 errors
• pyright (Microsoft): Industry standard - 0 errors

All packages now pass all three type checkers with zero errors.

Security Enhancements

• Ruff Security Audit: All S-rules (Bandit) warnings addressed
• SigV4 Signing: AWS X-Ray exporter uses proper AWS authentication
• Path Traversal Hardening: CWE-22 vulnerability fix in Dotprompt
• PySentry Integration: Continuous vulnerability scanning in CI
• License Compliance: All configuration files have proper headers

Critical Fixes

• Race Condition: Dev server startup race condition resolved (#4225)
• Thread Safety: Per-event-loop HTTP client caching prevents event loop binding errors (#4419, #4429)
• Infinite Recursion: Cycle detection in Handlebars partial resolution (via Dotprompt)
• Structured Output: DeepSeek model structured output generation (#4374)
• JSON Schema: None type handling per JSON Schema spec (#4247)

Performance

• Per-Event-Loop HTTP Client Caching: Reuses HTTP connections within event loops, prevents connection overhead
• Dotprompt Release Pipeline: Reduced from 30 minutes to 2 minutes (15x faster)
• CI Consolidation: Single workflow, every commit is release-worthy
• ty Type Checker: Faster type checking than pyright alone

Developer Experience

• Hot Reloading: Watchdog-based autoreloading for all samples
• Sample Improvements: Consistent run scripts, browser auto-open, rich tracebacks
• TODO Linting: Automated GitHub issue creation for TODOs
• Release Automation: bin/release_check, bin/bump_version scripts
• Consistency Checks: bin/check_consistency validates all packages

Migration Guide

For Application Developers

1. Update imports if you were using internal APIs
2. Use async/await for all Genkit operations
3. Test with Python 3.10+ (3.14 now supported)

For Plugin Developers

1. Migrate to PluginV2 base class
2. Follow new registration pattern in plugin docs
3. Run bin/lint to verify type safety

Testing

All 22 plugins and 40+ samples have been tested. CI runs on Python 3.10, 3.11, 3.12, 3.13, and 3.14.

Contributors

This release includes contributions from 13 developers across 188 PRs. Thank you to everyone who contributed!

Contributor	PRs	Commits	Key Contributions
@yesudeep	91	93	Core: async-first architecture (#4244), Genkit class methods (#4274), embed/embed_many API refactor (#4269), centralized action latency (#4267), array/enum/jsonl output formats (#4230). Plugins: AWS Bedrock (#4389), AWS X-Ray with SigV4 (#4390, #4402), Azure OpenAI (#4383), Cloudflare Workers AI (#4405), Mistral AI (#4406), Hugging Face (#4406), GCP telemetry (#4281). Type Safety: ty integration (#4094), pyrefly (#4316), pyright (#4310), comprehensive fixes (#4249-4270). DevEx: hot reloading (#4268), per-event-loop HTTP caching (#4419, #4429), PySentry security (#4273), TODO linting (#4376), CI consolidation (#4410), session/chat API (#4278, #4275), background models (#4327), docs (#4322, #4393, #4430). Samples: 20+ sample fixes and improvements (#4283, #4373, #4375, #4427).
@MengqinShen (Elisa Shen)	42	42	Core: Resource support implementation (#4204). Samples: menu sample fixes (#4239, #4403), short-n-long (#4404), tool-interrupt (#4408), prompt sample (#4223, #4183), ollama-hello (#4133), genai-image (#4122, #4234), code-execution (#4134), anthropic sample (#4131). Models: Google GenAI model config (#4306), TTS/Veo model config (#4411), Gemini bug fixes (#4432), system prompt fields (#4391, #4418). Docs: README updates (#4323), multi-round flow logic (#4137).
@AbeJLazaro	11	8	Plugins: Model Garden resolve/list actions (#3040), Ollama resolve action (#2972), type coverage and tests (#3011). Fixes: Gemini complex schema support (#3049), Firestore plugin naming (#3085), evaluator plugin requirements (#3166), optional dependencies setup (#3012). Tests: Model Garden tests (#3083).
@pavelgj	10	7	Core: Reflection API multi-runtime support (#3970), health check fixes (#3969). Fixes: Embedders reflection (#3969), Gemini version upgrades to 2.5 (#3909).
@zarinn3pal	9	9	Plugins: Anthropic (#3919), DeepSeek (#4051, structured output fix #4374), xAI/Grok (#4001, config #4289), ModelGarden (#2568). Telemetry: GCP telemetry for Firebase observability (#3826, #4386). Samples: OpenAI Compat tools (#3684).
@huangjeff5	7	7	Core: PluginV2 refactor with new registration pattern (#4132), type safety improvements (#4310), Pydantic output instances (#4413), session/chat refactor (#4321). Telemetry: Real-time telemetry and trace ID formatting (#4285).
@hendrixmar	7	7	Evaluators: ANSWER_RELEVANCY, FAITHFULNESS, MALICIOUSNESS metrics (#3806), ModelReference support (#3949, #3951). Plugins: OpenAI compat list_actions (#3240), resolve_method (#3055). Dotprompt: render_system_prompt (#3503), render_user_prompt (#3705).
@ssbushi	6	2	Evaluators: Simple evaluators plugin (#2835). Docs: MkDocs API reference updates (#2852), genkit-tools model optional (#3918).
@shrutip90	1	1	Types: ResourcePartSchema exports via genkit-tools (#3239).
@schlich	1	1	Types: Type annotations for ai module.
@ktsmadhav	1	1	Fixes: Windows support with file-safe timestamp format (#3727).
@junhyukhan	1	1	Docs: Typo fixes.
@CorieW	1	1	Community contribution.

google/dotprompt Contributors (Dotprompt Python integration):

Contributor	PRs	Commits	Key Contributions
@yesudeep	50+	100+	Rust Engine: dotpromptz-handlebars with PyO3/maturin (#365), Python 3.14 ABI support, Rust Handlebars runtime. Features: Cycle detection in partial resolution, path traversal hardening (CWE-22), directory/file prompt loading (#3955, #3971), Handlebars partials (#4088), callable prompts (#4053). Build: Bazel rules_dart/rules_flutter, release pipeline 15x faster (30min→2min), maturin wheel builds. IDE: Monaco syntax highlighting, CodeMirror 6 integration, Storybook demos. Polyglot: Python, Go, Dart, Rust, TypeScript implementations.
@MengqinShen	42	45	CI/CD: GitHub Actions workflows for Python package publishing, automated release-please, dotpromptz PyPI releases (0.1.2-0.1.5), handlebarrz releases, wheel artifact management.
@Zereker	1	1	Go: Closure fix preventing template sharing between instances.

Full Changelog

See CHANGELOG.md for the complete list of changes.