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npm / @ag-ui/client

@ag-ui/client

What changed in @ag-ui/client 1, from its official release notes, upgrade guides and advisories. Sources checked 2026-10-31.

11 breaking1 deprecations1 new APIs and options2 behavior and defaults

See which of these apply to your code, ranked, in your agent:

npx @unstale/cli init

@unstale/cli 0.2.9 on npm

@ag-ui/client 115 changes

Breaking changes 11

  • BinaryInputContent is retired from the public API; use image, audio, video, or document media parts with a source.

    1.0.0upgrade guide

  • EventEncoder omits optional protocol fields whose values are null before transmission; producers should emit the canonical absent-field shape.

    1.0.0upgrade guide

  • Validators are no longer re-exported by @ag-ui/client; import them from @ag-ui/core/schemas instead.

    1.0.0upgrade guide

  • The client enforces unknown-material stripping and malformed-value failures on paths with middleware and over protobuf, not only plain SSE.

    1.0.0upgrade guide

  • Repeated singular protobuf message fields are merged, including nested messages, metadata, and run inputs; later scalars win and repeated list entries append.

    1.0.0upgrade guide

  • The client fails a run when reasoning messages or spans are left open at RUN_FINISHED, in addition to rejecting orphaned fragments and reopens.

    1.0.0upgrade guide

  • Unknown keys on RunAgentInput are stripped before transmission; use forwardedProps for extra JSON intended for the agent.

    1.0.0upgrade guide

  • stripUnknown and StripResult are no longer exported from @ag-ui/client because they were enforcement-stage internals.

    1.0.0upgrade guide

  • The five THINKING_* events are retired from the public API; emit REASONING_* instead. Incoming legacy streams are translated by the compatibility boundary.

    1.0.0upgrade guide

  • Events with unrecognized types are dropped with a warning, and unknown properties on known events are stripped with a warning before subscribers see them.

    1.0.0upgrade guide

  • @ag-ui/client takes zod as a peer dependency; install it alongside the client because its enforcement stage validates with zod.

    1.0.0upgrade guide

Deprecations 1

  • AbstractAgent.maxVersion is deprecated in favor of maxProtocolVersion; overrides of the old name still work and warn once per process.

    1.0.0upgrade guide

New APIs and options 1

  • The client declares protocolVersion on every RunAgentInput and reads the producer's version on RUN_STARTED, warning for newer or uninterpretable versions.

    1.0.0upgrade guide

Behavior and default changes 2

  • Pin maxProtocolVersion below the client package version to omit protocolVersion for peers whose parsers reject unknown members.

    1.0.0upgrade guide

  • The client normalizes historically accepted whole optional null fields to absent before validation and warns for each translation.

    1.0.0upgrade guide