fix(spec): Remove reserved and fix tags ordering by herczyn · Pull Request #1494 · a2aproject/A2A

herczyn · 2026-02-17T20:50:48Z

fixes #1495 1495

gemini-code-assist · 2026-02-17T20:51:01Z

Summary of Changes

Hello @herczyn, 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 focuses on refining the protobuf specification by systematically reordering field tags within several messages and removing obsolete reserved field declarations. These changes aim to enhance the consistency and maintainability of the protocol definitions, ensuring a cleaner and more organized structure for future development.

Highlights

Protobuf Field Tag Reordering: Reordered field tags across multiple messages (e.g., Artifact, AgentCard, TaskPushNotificationConfig, and various request messages) to ensure sequential and logical ordering, improving specification clarity and potentially optimizing serialization.
Removal of Reserved Field Tags: Eliminated unnecessary reserved field tags from TaskStatusUpdateEvent, AgentCard, and AgentCapabilities messages, cleaning up the protobuf definitions by removing placeholders for previously used or deprecated fields.

Changelog

specification/a2a.proto
- Reordered field tags for name, description, parts, metadata, and extensions within the Artifact message.
- Removed reserved 4 and reordered metadata field tag in TaskStatusUpdateEvent.
- Removed reserved field tags (3, 9, 14, 15, 16) from AgentCard.
- Reordered field tags for supported_interfaces, security_requirements, signatures, and icon_url within the AgentCard message.
- Removed reserved 4 and reordered extended_agent_card field tag in AgentCapabilities.
- Reordered field tags for tenant, id, and push_notification_config within the TaskPushNotificationConfig message.
- Reordered field tags for tenant, message, configuration, and metadata within the SendMessageRequest message.
- Reordered field tags for tenant, id, and history_length within the GetTaskRequest message.
- Reordered field tags for tenant, context_id, status, page_size, page_token, history_length, status_timestamp_after, and include_artifacts within the ListTasksRequest message.
- Reordered field tags for tenant and id within the CancelTaskRequest message.
- Reordered field tags for tenant, task_id, and id within the GetTaskPushNotificationConfigRequest message.
- Reordered field tags for tenant, task_id, and id within the DeleteTaskPushNotificationConfigRequest message.
- Removed reserved 3 and reordered field tags for tenant, task_id, config_id, and config within the CreateTaskPushNotificationConfigRequest message.
- Reordered field tags for tenant and id within the SubscribeToTaskRequest message.

Activity

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Code Review

This pull request aims to reorder Protobuf field tags and remove reserved keywords. While the intention might be to optimize field numbering, the current implementation introduces critical backward compatibility issues. In Protobuf, field numbers are part of the wire format and must remain stable. Reusing field numbers for different field types or removing reserved statements without careful consideration can lead to data corruption when deserializing older data. It is crucial to ensure that once a field number is assigned, it is either kept for the same field or explicitly marked as reserved if the field is removed, to prevent its reuse for a different field.

specification/a2a.proto

muscariello

LGTM

🤖 I have created a release *beep* *boop* --- ## [1.0.0](v0.3.0...v1.0.0) (2026-03-12) ### ⚠ BREAKING CHANGES * **spec:** Combine `TaskPushNotificationConfig` and `PushNotificationConfig` ([#1500](#1500)) * **spec:** remove duplicated ID from the create task push config request ([#1487](#1487)) * **spec:** pluralize configs in `ListTaskPushNotificationConfigs` ([#1486](#1486)) * **spec:** Add LF prefix to the package. ([#1474](#1474)) * **spec:** Switch to non-complex IDs in requests ([#1389](#1389)) * **spec:** Standardize spelling of "canceled" to use American Spelling throughout ([#1283](#1283)) * **spec:** Align enum format with ADR-001 ProtoJSON specification ([#1384](#1384)) * **spec:** Remove redundant `final` field from `TaskStatusUpdateEvent` ([#1308](#1308)) * **spec:** Move `extendedAgentCard` field to `AgentCapabilities` ([#1307](#1307)) * **spec:** Fixes for the last_updated_after field ([#1358](#1358)) * **spec:** modernize oauth 2.0 flows - remove implicit/password, add device code / pkce ([#1303](#1303)) * **spec:** Make "message" field name consistent between protocol bindings ([#1302](#1302)) * **spec:** Remove deprecated fields from a2a.proto for v1.0 release ([#1301](#1301)) * **spec:** Rename `supportsAuthenticatedExtendedCard` to `supportsExtendedAgentCard` ([#1222](#1222)) * **spec:** Remove v1s from a2a url http bindings * **spec:** Large refactor of specification to separate application protocol definition from mapping to transports ### Features * **spec:** Add `tasks/list` method with filtering and pagination to the specification ([0a9f629](0a9f629)) * **spec:** modernize oauth 2.0 flows - remove implicit/password, add device code / pkce ([#1303](#1303)) ([525ff38](525ff38)) * **spec:** Natively Support Multi-tenancy on gRPC through an additional scope field on the request. ([#1195](#1195)) ([cfbce32](cfbce32)), closes [#1148](#1148) * **spec:** Provide ability for SDKs to be backwards compatible. ([#1401](#1401)) ([227e249](227e249)) * **spec:** Remove v1s from a2a url http bindings ([1bd263f](1bd263f)) ### Bug Fixes * Add missing metadata field to Part message in gRPC specification ([#1019](#1019)) ([b3b266d](b3b266d)), closes [#1005](#1005) * Add name field to FilePart protobuf message ([#983](#983)) ([2b7cb6f](2b7cb6f)), closes [#984](#984) * Clarify blocking calls return on interrupted states ([#1403](#1403)) ([0655ff3](0655ff3)) * **doc:** Makes JSON-RPC SendMessage response clearer ([#1241](#1241)) ([5792804](5792804)) * **docs:** Clearer wording around context id. ([#1588](#1588)) ([dec790a](dec790a)) * **grpc:** Fix inconsistent property name between gRPC and JSON-RPC in Message object ([#1100](#1100)) ([2a1f819](2a1f819)) * **grpc:** missing field in gRPC spec - state_transition_history ([#1138](#1138)) ([a2de798](a2de798)), closes [#1139](#1139) * **grpc:** Update `CreateTaskPushNotificationConfig` endpoint to `/v1/{parent=tasks/*/pushNotificationConfigs}` ([#979](#979)) ([911f9b0](911f9b0)) * **proto:** Add icon_url to a2a.proto ([#986](#986)) ([17e7f62](17e7f62)) * **proto:** Adds metadata field to A2A DataPart proto ([#1004](#1004)) ([a8b45dc](a8b45dc)) * Remove unimplemented state_transition_history capability field ([#1396](#1396)) ([c768a44](c768a44)), closes [#1228](#1228) * Restore CreateTaskPushNotificationConfig method naming ([#1402](#1402)) ([d14f410](d14f410)) * Revert "chore(gRPC): Update a2a.proto to include metadata on GetTaskRequest" ([#1000](#1000)) ([e6b8c65](e6b8c65)) * Simplify Part message structure by flattening FilePart and DataPart ([#1411](#1411)) ([bfae8f7](bfae8f7)) * **spec:** Add LF prefix to the package. ([#1474](#1474)) ([a54e809](a54e809)) * **spec:** add metadata to `CancelTaskRequest` ([#1485](#1485)) ([c441b91](c441b91)), closes [#1484](#1484) * **spec:** Added clarification on timestamps in HTTP query params ([#1425](#1425)) ([6292104](6292104)) * **spec:** Added clarifying text around messages and artifacts ([#1424](#1424)) ([b03d141](b03d141)) * **spec:** Adjust field number for `ListTasksRequest.tenant` to prevent missing number ([#1470](#1470)) ([cd16c52](cd16c52)) * **spec:** Clarify contextId behavior when message is sent with taskId but without contextId ([#1309](#1309)) ([a336a5a](a336a5a)) * **spec:** Clarify versioning strategy and client responsibilities in protocol specification ([#1259](#1259)) ([a4afeea](a4afeea)) * **spec:** Fix/1251 clarify authentication scheme ([#1256](#1256)) ([3e6c7db](3e6c7db)) * **spec:** Fixes for the last_updated_after field ([#1358](#1358)) ([0e204bf](0e204bf)) * **spec:** Make "message" field name consistent between protocol bindings ([#1302](#1302)) ([1e5f462](1e5f462)), closes [#1230](#1230) * **spec:** make `history_length` optional ([#1071](#1071)) ([0572953](0572953)) * **spec:** pluralize configs in `ListTaskPushNotificationConfigs` ([#1486](#1486)) ([cf735cb](cf735cb)) * **spec:** Remove config from binding. ([#1587](#1587)) ([010b9cc](010b9cc)) * **spec:** Remove deprecated fields from a2a.proto for v1.0 release ([#1301](#1301)) ([60f83c3](60f83c3)), closes [#1227](#1227) * **spec:** remove duplicated ID from the create task push config request ([#1487](#1487)) ([393898d](393898d)) * **spec:** Remove metadata field from ListTasksRequest ([#1235](#1235)) ([b6ef9ee](b6ef9ee)) * **spec:** Remove reserved and fix tags ordering ([#1494](#1494)) ([1997c9d](1997c9d)) * **spec:** Rename `supportsAuthenticatedExtendedCard` to `supportsExtendedAgentCard` ([#1222](#1222)) ([c196824](c196824)), closes [#1215](#1215) * **spec:** Standardize spelling of "canceled" to use American Spelling throughout ([#1283](#1283)) ([4dd980f](4dd980f)) * **spec:** Suggest Unique Identifier fields to be UUID ([#966](#966)) ([00cf76e](00cf76e)) * **spec:** Switch to non-complex IDs in requests ([#1389](#1389)) ([2596c1c](2596c1c)), closes [#1390](#1390) * **spec:** Update security schemes example ([#1364](#1364)) ([f9a8f5b](f9a8f5b)) * Update the Java tutorials and descriptions ([#1181](#1181)) ([202aa06](202aa06)) ### Documentation * **spec:** Align enum format with ADR-001 ProtoJSON specification ([#1384](#1384)) ([810eaa1](810eaa1)), closes [#1344](#1344) ### Code Refactoring * **spec:** Combine `TaskPushNotificationConfig` and `PushNotificationConfig` ([#1500](#1500)) ([d1ed0da](d1ed0da)) * **spec:** Large refactor of specification to separate application protocol definition from mapping to transports ([b078419](b078419)) * **spec:** Move `extendedAgentCard` field to `AgentCapabilities` ([#1307](#1307)) ([40d6286](40d6286)) * **spec:** Remove redundant `final` field from `TaskStatusUpdateEvent` ([#1308](#1308)) ([5b101cc](5b101cc)) --- 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: Amye Scavarda Perrin <amye@amye.org> Co-authored-by: Holt Skinner <13262395+holtskinner@users.noreply.github.com>

herczyn added 2 commits February 17, 2026 20:48

Reorder tags and remove reserved.

09e4697

fix formating

fdd4b96

herczyn requested a review from a team as a code owner February 17, 2026 20:50

Merge branch 'main' into tags_ordering

43bdfe3

gemini-code-assist bot reviewed Feb 17, 2026

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herczyn mentioned this pull request Feb 17, 2026

[Feat]: Fix numbering in a2a.proto #1495

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muscariello approved these changes Feb 17, 2026

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amye merged commit 1997c9d into a2aproject:main Feb 17, 2026
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a2a-bot mentioned this pull request Feb 17, 2026

chore(main): release 1.0.0 #1221

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fix(spec): Remove reserved and fix tags ordering#1494

fix(spec): Remove reserved and fix tags ordering#1494
amye merged 3 commits intoa2aproject:mainfrom
herczyn:tags_ordering

herczyn commented Feb 17, 2026 •

edited

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herczyn commented Feb 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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herczyn commented Feb 17, 2026 •

edited

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