CHANGELOG.md

Changelog

2.6.0 (2026-09-25)

Features

• a2acrypto: add AgentCard JWS signing and verification (fixes #141) (#368) (b03b830)
• itk: use shared scenarios (#429) (e54a070)

Bug Fixes

• a2acrypto canonicalization and refactoring (#441) (012cc74)
• a2asrv: return spec error codes for terminal and parked tasks (#438) (#442) (a2f11cb)
• align ListTasks timestamp query parameter (#425) (621e01e)
• ci: skip scheduled nightly workflows on forks (#427) (03b1f84), closes #426
• compare recovery timestamps by value (#428) (b3d23f5)
• support ProtoJSON security requirement scopes in Agent Cards (#437) (76da16e)

2.5.0 (2026-08-18)

Features

• agent executor constructor helper (#418) (0f45c92)
• cli supports full agent card urls (#413) (d5d1cec), closes #412
• cli: polling fallback for servers which don't support streaming (#419) (b5b9f85)
• make agentcard resolver handler file:// (#424) (e1c3cc0)
• utilities for working with a2a events (#416) (1b8cac7)

Bug Fixes

• added missing converters and made sure a2agrpc uses pbconv (#421) (579cff8)
• cli not parsing compat agent cards (#415) (bebdcee)
• handle negative historyLength as empty history request (#393) (f4d5882)
• jsonrpc: lenient decode of error.data to preserve server errors (#386) (497cbac)
• remove empty contextId check in proto converter (#392) (758c7a1)
• sse: buffer REST SSE panicChan to avoid goroutine leak on client disconnect (#396) (ff6035b)
• taskexec: close event-queue reader on cancel early exits (#409) (14e41a9)

2.4.0 (2026-07-28)

Features

• provide generic pull event queue (#354) (6a48d4b)
• push: push sender SSRF protection enabled by default (fixes #373) (#374) (0a4f17a)

Bug Fixes

• a2acompat/a2av0: implement A2A v0.3 REST wire format (#371) (1ca80f9), closes #370
• a2asrv: skip TaskID mismatch check when message has no task reference (fixes #350) (#359) (8c0dd99)
• allow empty request bodies and enable GET method for task subscriptions (#381) (8363365), closes #380
• cli: emit non-null required Agent Card list fields in synthesized card (fixes #369) (#372) (0640869)
• eventqueue: add JSON marshal/unmarshal to Message so events survive roundtrip (fixes #349) (#360) (d52d5a1)
• itk grpc compatibility for v0.3 SDKs (#367) (11340a7)
• ListTaskshistoryLength missing (8b91364)
• ListTaskshistoryLength missing (issue #355) (#361) (8b91364)
• taskstore,push: enforce cross-tenant authorization on Get and push config stores (#357) (a9f9c64)

2.3.1 (2026-05-13)

Bug Fixes

• workqueue implementation missed events (#340) (d1b9a6b)

2.3.0 (2026-05-12)

Features

• add WithAgentInactivityTimeout option for terminating stalled a… (#315) (357bb11)
• workqueue finalization (#324) (8b4bbf6), closes #200

Bug Fixes

• a2acompat: correct OAuth2 round-trip through compat producer/parser (#337) (4dfb802)
• make push config listing return correct json response (#338) (7c89490)

2.2.1 (2026-04-29)

Bug Fixes

• compat package fixes (#328) (21e166c)
• deserialize REST streaming error events into typed A2A errors (#318) (#319) (8a250ad)
• extra query and fast client rejection in local executor (#330) (f307ca9)
• task push notification configurations (#329) (c78fb4d)
• update error handling to match spec (#327) (1aa72ce)

2.2.0 (2026-04-10)

Features

• add tenant propagation (#316) (26d2ced)
• cli (#307) (e04fc68)

Bug Fixes

• incorrect decoding of CreateTaskPushConfig request body (#314) (769dfe4)

2.1.0 (2026-04-01)

Features

• observability improvements (#295) (0c90bc7)

Bug Fixes

• blocking=true compatibility (#305) (8fbdbee), closes #301
• correct json discriminator keys (#298) (dfb4052)
• correct json discriminator keys (#300) (b4471e6)

2.0.1 (2026-03-24)

Features

• a2acompat: add HTTP+JSON REST support to a2av0 compat layer (#280) (bac00e7)
• agent executor cleaner (#276) (9c95980)

Bug Fixes

• ensure correct concurrent cancellation results (#287) (d0f8981), closes #245

Documentation

• a2aclient: add Example_* test functions for pkg.go.dev documentation (#263) (f8dae97)
• update diagrams, docs and instructions (#289) (ed33c7a)

1.0.0 (2026-03-17)

Features

• implement the new rest error handling (#282) (a3bda30)
• use v2 suffix for module ID and provide compat support (#270) (dd1b6ba), closes #250

Bug Fixes

• a2asrv jsonrpc Content-Type (#265) (2568a46)
• bugs before going from alpha (#279) (b1f055c)
• GetTaskRequest nil pointer assignment check (#258) (440bb79)
• inject headers into service params (#277) (d33f3bd), closes #275
• propagate cancelation signal using task store (#272) (5e1d462), closes #245
• regenerate spec and fix returnImmediately (#284) (2eee0b9)
• task modified after save (#266) (c15febe)
• taskupdater result mutable (#274) (6038d92)
• update pushsender (#256) (5f7a594)
• use enum values as in the spec (#261) (eb98981), closes #251

Documentation

• a2asrv: add Example_* test functions for pkg.go.dev documentation (#262) (7888e37)
• add example tests a2a (#240) (4fe08a9)

1.0.0-alpha.3 (2026-02-27)

Bug Fixes

• a2a.Part metadata handling fixed.

1.0.0-alpha.2 (2026-02-27)

Versioning is introduced on the SDK level, the new version is github.com/a2aproject/a2a-go/v1.

Features

• gRPC protocol binding uses standard google.rpc.ErrorInfo for error details.
• a2asrv.NewTenantRESTHandler provides a utility for setting up multi-tenant deplyments.
• a2a.Task snapshot is emitted as the first event on task resubscription.
• REST transport supports configurable keep-alive and panic recovery for SSE connections.
• a2asrv.WithCapabilityChecks handler option rejecting requests for which no support is declared in a2a.AgentCapabilities.
• a2acompat works against the old github.com/a2aproject/a2a-go library and provides adapters for common dependencies.
• Compatibility handling of extensions header.

Bug Fixes

• JSONRPC handler request scope is not terminated when panic is recovered during SSE streaming.
• Correct HistoryLength handling for 0 and nil cases.

1.0.0-alpha (2026-02-23)

Features

Implements A2A spec 1.0-rc revision with JSONRPC and gRPC protocol bindings.

Non-breaking changes

• a2aclient.Factory implements protocol version negotiation.
• New errors added: ExtensionSupportRequiredError and VersionNotSupportedError.
• Client sends A2A-Version header.
• ListTasks RPC implementation.
• a2a package provides Part constructor functions.

Spec-specific breaking changes

In addition to breaking core type changes updates:

• Agent output validations: task must be the first event emitted by AgentExecutor, artifact parts must be non-empty.
• Final field removed from TaskStatusUpdateEvent, state is used to determine whether event is final.
• RPCs renamed: TaskSubscription -> SubscribeToTask, GetAgentCard -> GetExtendedAgentCard.
• JSONRPC uses the same method naming as gRPC.

SDK breaking changes:

For motivation behind some of the changes refer to the change announcement.

• a2asrv.AgentExecutor changes: Execute and Cancel now return iter.Seq2[a2a.Event, error] instead of writing events to a queue.
• a2asrv/taskstore package gets introduced with TaskStore interface and the the default in-memory implementation.
• a2a.TaskVersion gets moved to a2asrv/taskstore.
• TaskStore.Save method gets replaced with separate Create and Update methods.
• TaskStore.Update is called with a2a.Event set to user a2a.Message on task history update.
• TaskStore.Get return types is taskstore.StoredTask which is (task, version) pair.
• eventqueue.Queue gets replaced with separate eventqueue.Reader and eventqueue.Writer. eventqueue.Manager methods updated appropriately.
• eventqueue.Message gets introduced for grouping a2a.Task, taskstore.TaskVersion and a2a.ProtocolVersion.
• a2aclient.CallInterceptor and a2asrv.CallInterceptor can now return a value from Before to return a result without performing the actual call.
• a2aclient.WithInterceptors gets renamed to a2aclient.WithCallInterceptors and a2asrv.WithCallInterceptor gets renamed to a2asrv.WithCallInterceptors and takes vararg so that methods are consistent with each other.
• a2asrv.User get changed from an interface to a struct with an Attributes map[string]any field.
• a2asrv.RequestContext gets renamed into a2asrv.ExecutorContext. User and ServiceParams are added to the struct, these should be used intead of CallContext.
• a2asrv.ReqMeta and a2aclient.CallMeta are renamed to ServiceParams.
• a2asrv.PushSender and a2asrv.PushConfigStore are moved to a2asrv/push.
• a2aclient.ServiceParams are now passed explicitly to a2aclient.Transport.
• Methods which attach something to context.Context start with Attach prefix, methods used to create constructor-function options start with With.
• a2aclient.NewStaticServiceParamsInjector replaced with a2aclient.AttachServiceParams for sending request headers.
• gRPC transport for a2aclient was moved to a2agrpc package. This removes gRPC as the mandatory dependency from the client.

v0.3 compatibility:

Backward compatibility implementation as discussed in A2A spec repo is provided by github.com/a2aproject/a2a-go/a2acompat/a2av0 package.

a2agrpc and a2apb are versioned, where v0 contains mappers from v0.3.6 types to core types, and v1 implements the latest protocol version.

For an example backward-compatibility setup refer to e2e/compat.

0.3.7 (2026-02-20)

Features

• implement tasks/list RPC (#210) (6e04698)
• retry cancelations (#222) (3057474)

Bug Fixes

• handle internal error: tck failure (#186) (b55fbfd)
• sse: support data: prefix without space (#188) (6657a6d), closes #162

0.3.6 (2026-01-30)

Features

• callinterceptor supports payload override (#177) (baf66d8)
• callinterceptor supports payload override-client (#181) (1d74565)
• custom errors (#180) (2152258)
• custom panic handler (#185) (d3af3bf)
• db-backend cluster setup (#133) (4f7471c), closes #115
• extension utilities (#165) (6c78425)

Bug Fixes

• add opt-in keep-alive. Fixes #168 (#171) (64880fc)
• reflect origin if provided when serving public agentcard (#183) (535bb1f), closes #174

0.3.5 (2026-01-23)

Bug Fixes

• added MessageSendParams validations in handleSendMessage (#160) (1c66cb3)
• Address default blocking for JSONRpc server (#156) (5a5b403)
• final event overriding task failure event (#172) (8a97b84)
• return correct jsonrpc errors (#161) (950ce82)
• return the root cause of the error. Fixes #167 (#169) (b699c67)
• wrong field set as meta (#164) (2173f5e), closes #163

0.3.4 (2026-01-14)

Features

• introduce and integrate TaskVersion (#127) (5cf0332)
• taskstore list (#126) (9987486)
• taskstore pagination (#136) (fffb4d4)
• workqueue (#132) (dcc3a89), closes #115

Bug Fixes

• nil parts must be empty array when encoded to JSON (#140) (049190c)
• provide request-level metadata in RequestContext (#152) (bf3096c)
• sse: increase buffer size for large SSE payloads (#149) (1287239)

0.3.3 (2025-12-08)

Features

• allow creating grpc transport from service client (#117) (e95c064)
• concurrency control (#110) (4e8bcc1)

Bug Fixes

• increase default timeout on jsonrpc client to account for streaming (#134) (6d7290b), closes #125
• make log package capture the source properly (#112) (0ec064d)
• return a task in failed state as a result (#114) (80e20aa)

Documentation

• Added CONTRIBUTING.md. (#119) (f666ec6)

0.3.2 (2025-11-14)

Bug Fixes

• allow request meta extension and hide mistakenly exported type (#106) (46fa0cb)

0.3.1 (2025-11-13)

Bug Fixes

• nil meta becomes empty struct in send message conversion (#105) (60d3fcb)
• remove keep-alive messages (#100) (493e497)
• use UUIDv7 in type ID generators (#102) (3a809ea), closes #101

0.3.0 (2025-11-04)

Features

• add JSON-RPC client transport implementation (#79) (1690088)
• agent card resolver (#48) (0951293)
• blocking flag handling (#97) (f7aa465), closes #96
• client API proposal (#32) (b6ca54f)
• client auth interceptor (#90) (25b9aae)
• client interceptor invocations (#51) (3e9f2ae)
• core types JSON codec (#42) (c5b3982)
• define core types and interfaces (#16) (69b96ea)
• disallow custom types and circular refs in Metadata (#43) (53bc928)
• get task implementation (#59) (f74d854)
• grpc authenticated agent card and producer utils (#85) (9d82f31), closes #82
• grpc client transport (#66) (fee703e)
• grpc code generation from A2A .proto spec (#11) (2993b98)
• handling artifacts and implementing send message stream (#52) (c3fa631)
• implement an a2aclient.Factory (#50) (49deee7)
• implementing grpc server wrapper (#37) (071e952)
• implementing message-message interaction (#34) (b568979)
• implementing task pushes (#86) (c210240)
• input-required and auth-required handling (#70) (3ac89ba)
• jsonrpc server (#91) (5491030)
• logger (#56) (86ab9d2)
• request context loading (#60) (ab7a29b)
• result aggregation part 1 - task store (#38) (d3c02f5)
• result aggregation part 3 - concurrent task executor (#40) (265c3e7)
• result aggregation part 4 - integration (#41) (bab72d9)
• SDK type utilities (#31) (32b77b4)
• server middleware API (#63) (738bf85)
• server middleware integration (#64) (5dc8be0)
• smarter a2aclient (#88) (322d05b)
• task event factory (#95) (fbf3bcf), closes #84
• task executor docs (#36) (b6868df)
• task update logic (0ac987f)

Bug Fixes

• Execute() callers missing events (#74) (4c3389f)
• mark task failed when execution fails (#94) (ee0e7ed)
• push semantics update (#93) (76bff9f)
• race detector queue closed access (c07b7d0)
• regenerate proto and update converters (#81) (c732060)
• streaming (#92) (ca7a64b)

Miscellaneous Chores

• release 0.3.0 (fa7cfba)