feat: Add RESTful API Serving #348
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# Adding stand-alone support for RESTful API serving Though the RESTful API (JSON+HTTP) can be served from an envoy transcoding of the gRPC service that may not always make sense in all cases. Instead, this PR also adds the ability to serve the RESTful API stand-alone, without needing to also setup the gRPC service. --------- Co-authored-by: Holt Skinner <[email protected]> Co-authored-by: swapydapy <[email protected]>
…s and simplify client interfaces (#342) # Description Refactor the client codebase to support automated, configurable, client factory to generate a client based on the agent card details. Adds support for generation of clients based on JSONRPC, gRPC and RESTful interfaces. --------- Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com> Co-authored-by: Holt Skinner <[email protected]> Co-authored-by: Holt Skinner <[email protected]>
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Summary of Changes
Hello @holtskinner, I'm Gemini Code Assist1! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!
This pull request significantly refactors the client-side architecture to support multiple communication transports (JSON-RPC, gRPC, and a newly introduced RESTful API) for interacting with agents. It also adds the necessary server-side components to enable agents to serve their functionalities via a RESTful interface. These changes enhance the flexibility and interoperability of the system by allowing clients and agents to negotiate and utilize the most suitable communication protocol.
Highlights
- Multi-Transport Client Refactor: Introduced an abstract
Clientinterface and concrete implementations for JSON-RPC, gRPC, and a new RESTful API, enabling flexible communication with agents. The previousA2AClientis now aliased for backward compatibility. - New Client Factory: Added a
ClientFactoryto dynamically create the appropriate client instance based on the agent's advertised capabilities and the client's configured preferences, simplifying client instantiation and transport negotiation. - RESTful API Serving: Implemented a new RESTful API layer for agents, including
RESTApplicationandA2ARESTFastAPIApplication, allowing agents to expose their functionalities via standard HTTP/JSON endpoints. This new API leverages Protocol Buffers for data consistency. - Centralized Task Management: Introduced
ClientTaskManagerto standardize the handling and updating ofTaskobjects and related events across different client transports, centralizing state management. - Transport Enumeration: A new
Transportsenum has been added to define standard protocol transport labels (GRPC, JSONRPC, RESTful), improving clarity and type safety.
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Code Review
This pull request introduces multi-transport support for the client, including a new RESTful API implementation. The introduction of a ClientFactory and a common Client interface is a great step towards a more maintainable and extensible client library. However, I've identified several critical issues, particularly in the new REST client and server implementations, as well as some regressions and incomplete features in the new transport clients. Please see my detailed comments below.
Looks like a merge failure Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
Lock file update with latest dev dependencies
…ad of global installations
…ase variable renaming and module name change for patches
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A refactor of the refactor. This pulls out the common code from across transport-specific clients into one BaseClient, then shoves all the transport-specific code into implementations of `ClientTransport`. --------- Co-authored-by: Holt Skinner <[email protected]>
Fix merge conflicts when merging from main
… app frameworks to request handlers - This avoids confusion between frameworks like fast api app and the rest application (which does not have any server hosting)
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Code Review
This pull request introduces a significant and valuable refactoring of the client architecture to support multiple transport protocols, and adds a new RESTful API for the server. The changes are extensive, touching many parts of the codebase, and generally move the project in a good direction by improving modularity and extensibility.
I've identified a few key areas for improvement:
- Interceptor Implementation: The new
RestTransportandGrpcTransportdo not seem to apply client-side interceptors, which is a critical feature for functionality like authentication. This needs to be addressed to ensure consistent behavior across all transports. - Encapsulation: There's an instance of accessing a "protected" member from outside its class, which could be improved by adjusting the member's visibility.
Overall, this is a great step forward for the project. Addressing the feedback below will help ensure the new architecture is robust, consistent, and secure.
🤖 I have created a release *beep* *boop* --- ## [0.3.0](v0.2.16...v0.3.0) (2025-07-31) ### ⚠ BREAKING CHANGES * **deps:** Make opentelemetry an optional dependency ([#369](#369)) * **spec:** Update Agent Card Well-Known Path to `/.well-known/agent-card.json` ([#320](#320)) * Remove custom `__getattr__` and `__setattr__` for `camelCase` fields in `types.py` ([#335](#335)) * Add mTLS to SecuritySchemes, add oauth2 metadata url field, allow Skills to specify Security ([#362](#362)) * Support for serving agent card at deprecated path ([#352](#352)) ### Features * Add `metadata` as parameter to `TaskUpdater.update_status()` ([#371](#371)) ([9444ed6](9444ed6)) * Add mTLS to SecuritySchemes, add oauth2 metadata url field, allow Skills to specify Security ([#362](#362)) ([be6c517](be6c517)) * Add RESTful API Serving ([#348](#348)) ([82a6b7c](82a6b7c)) * Add server-side support for plumbing requested and activated extensions ([#333](#333)) ([4d5b92c](4d5b92c)) * Allow agent cards (default and extended) to be dynamic ([#365](#365)) ([ee92aab](ee92aab)) * Support for serving agent card at deprecated path ([#352](#352)) ([2444034](2444034)) * support non-blocking `sendMessage` ([#349](#349)) ([70b4999](70b4999)) * Type update to support fetching extended card ([#361](#361)) ([83304bb](83304bb)) ### Bug Fixes * Add Input Validation for Task Context IDs in new_task Function ([#340](#340)) ([a7ed7ef](a7ed7ef)) * **deps:** Reduce FastAPI library required version to `0.95.0` ([#372](#372)) ([a319334](a319334)) * Remove `DeprecationWarning` for regular properties ([#345](#345)) ([2806f3e](2806f3e)) * **spec:** Add `SendMessageRequest.request` `json_name` mapping to `message` proto ([bc97cba](bc97cba)) * **spec:** Add Transport enum to specification (a2aproject/A2A#909) ([d9e463c](d9e463c)) ### Documentation * Address typos in docstrings and docs. ([#370](#370)) ([ee48d68](ee48d68)) ### Miscellaneous Chores * Add support for authenticated extended card method ([#356](#356)) ([b567e80](b567e80)) ### Code Refactoring * **deps:** Make opentelemetry an optional dependency ([#369](#369)) ([9ad8b96](9ad8b96)) * Remove custom `__getattr__` and `__setattr__` for `camelCase` fields in `types.py` ([#335](#335)) ([cd94167](cd94167)) * **spec:** Update Agent Card Well-Known Path to `/.well-known/agent-card.json` ([#320](#320)) ([270ea9b](270ea9b)) --- This PR was generated with [Release Please](https://github.com/googleapis/release-please). See [documentation](https://github.com/googleapis/release-please#release-please). Co-authored-by: release-please[bot] <55107282+release-please[bot]@users.noreply.github.com>
refactor: Update client code to support multi-transport
refactor: Refactor client into BaseClient + ClientTransport #363