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Workflow

Package github.com/digitallysavvy/go-ai/pkg/workflow is the Go port of the TypeScript @ai-sdk/workflow package. It provides an agent for durable execution, where one run spans several process executions, and the client and server pieces that stream a run to a chat UI. For a walkthrough of WorkflowAgent, see WorkflowAgent.

WorkflowAgent

workflow.NewWorkflowAgent validates a WorkflowAgent value and returns it.

func NewWorkflowAgent(agent WorkflowAgent) (*WorkflowAgent, error)

Field	Type	Description
`Model`	`provider.LanguageModel`
`System`	`string`
`Instructions`	`interface{}`	Instructions is the TypeScript-compatible name for system instructions.
`AllowSystemInMessages`	`bool`	AllowSystemInMessages permits system-role messages in Messages. By default WorkflowAgent rejects system messages; use Instructions/System for default system prompts.
`Tools`	`[]types.Tool`
`ToolSet`	`map[string]types.Tool`
`StopWhen`	`[]ai.StopCondition`
`Output`	`interface{}`
`Telemetry`	`*ai.TelemetrySettings`
`ID`	`string`
`Prompt`	`string`
`OnStart`	`StartCallback`
`OnStepStart`	`StepStartCallback`
`OnToolExecutionStart`	`ToolExecutionStartCallback`
`OnToolExecutionEnd`	`ToolExecutionEndCallback`
`OnStepEnd`	`StepEndCallback`
`OnStepFinish`	`StepFinishCallback`	Deprecated: use OnStepEnd.
`OnEnd`	`EndCallback`
`OnFinish`	`FinishCallback`	Deprecated: use OnEnd.
`OnError`	`ErrorCallback`
`OnAbort`	`AbortCallback`
`PrepareCall`	`PrepareCallHook`
`PrepareStep`	`PrepareStepHook`
`FilterActiveTools`	`FilterActiveToolsHook`
`CallOptionsSchema`	`schema.Schema`
`CallOptions`	`interface{}`
`ActiveTools`	`[]string`
`Temperature`	`*float64`
`MaxTokens`	`*int`
`TopP`	`*float64`
`TopK`	`*int`
`FrequencyPenalty`	`*float64`
`PresencePenalty`	`*float64`
`StopSequences`	`[]string`
`Seed`	`*int`
`Headers`	`map[string]string`
`Reasoning`	`*types.ReasoningLevel`
`SendReasoning`	`*bool`
`ProviderOptions`	`map[string]interface{}`
`RuntimeContext`	`interface{}`
`ToolsContext`	`map[string]interface{}`
`ToolChoice`	`types.ToolChoice`
`Include`	`*ai.IncludeOptions`
`ExperimentalSandbox`	`interface{}`
`ExperimentalRefineToolInput`	`map[string]ai.ToolInputRefiner`
`RepairToolCall`	`ai.ToolCallRepairFunction`	RepairToolCall attempts to repair tool calls that fail to parse.
`ExperimentalRepairToolCall`	`ai.ToolCallRepairFunction`	ExperimentalRepairToolCall is a deprecated alias for RepairToolCall. Deprecated: use RepairToolCall.
`ExperimentalToolApprovalSecret`	`[]byte`	ExperimentalToolApprovalSecret signs issued approval requests and verifies resumed approvals before approved tools execute.
`MaxRetries`	`*int`	MaxRetries controls transient provider call retries for each model call, forwarded to agent.AgentConfig.MaxRetries. Defaults to 2 when nil, matching TS WorkflowAgent's `mergedGenerationSettings.maxRetries ?? 2`.
`Timeout`	`*ai.TimeoutConfig`	Timeout provides granular timeout controls, forwarded to agent.AgentConfig.Timeout.
`ExperimentalDownload`	`ai.DownloadFunction`	ExperimentalDownload customizes remote file URL downloads before model calls, forwarded to agent.AgentConfig.ExperimentalDownload.

Method	Description
`Generate(ctx, prompt string, opts agent.AgentGenerateOptions) (WorkflowResult, error)`	Runs the agent and returns the final result.
`GenerateWithOptions(ctx, WorkflowGenerateOptions) (*WorkflowResult, error)`	Runs with workflow-native call options.
`Stream(ctx, prompt string, opts agent.AgentStreamOptions) (WorkflowStreamResult, error)`	Runs in streaming mode.
`StreamWithOptions(ctx, WorkflowStreamOptions) (*WorkflowStreamResult, error)`	Streams with workflow-native stream options.

WorkflowGenerateOptions

Field	Type	Description
`Prompt`	`string`
`Messages`	`[]types.Message`
`System`	`string`
`Instructions`	`interface{}`
`AllowSystemInMessages`	`bool`
`Tools`	`[]types.Tool`
`ToolSet`	`map[string]types.Tool`
`StopWhen`	`[]ai.StopCondition`
`Telemetry`	`*ai.TelemetrySettings`
`RuntimeContext`	`interface{}`
`ToolsContext`	`map[string]interface{}`
`Include`	`*ai.IncludeOptions`
`ExperimentalSandbox`	`interface{}`
`ExperimentalRefineToolInput`	`map[string]ai.ToolInputRefiner`
`RepairToolCall`	`ai.ToolCallRepairFunction`	RepairToolCall attempts to repair tool calls that fail to parse.
`ExperimentalRepairToolCall`	`ai.ToolCallRepairFunction`	ExperimentalRepairToolCall is a deprecated alias for RepairToolCall. Deprecated: use RepairToolCall.
`ExperimentalToolApprovalSecret`	`[]byte`	ExperimentalToolApprovalSecret overrides the agent's approval secret.
`MaxRetries`	`*int`	MaxRetries overrides the agent's MaxRetries for this call.
`Timeout`	`*ai.TimeoutConfig`	Timeout overrides the agent's Timeout for this call.
`ExperimentalDownload`	`ai.DownloadFunction`	ExperimentalDownload overrides the agent's ExperimentalDownload for this call.
`OnStart`	`StartCallback`
`OnStepStart`	`StepStartCallback`
`OnToolExecutionStart`	`ToolExecutionStartCallback`
`OnToolExecutionEnd`	`ToolExecutionEndCallback`
`OnStepEnd`	`StepEndCallback`
`OnStepFinish`	`StepFinishCallback`	Deprecated: use OnStepEnd.
`OnEnd`	`EndCallback`
`OnFinish`	`FinishCallback`	Deprecated: use OnEnd.
`OnError`	`ErrorCallback`
`OnAbort`	`AbortCallback`

WorkflowStreamOptions

Field	Type	Description
`Prompt`	`string`
`Messages`	`[]types.Message`
`System`	`string`
`Instructions`	`interface{}`
`AllowSystemInMessages`	`bool`
`Tools`	`[]types.Tool`
`ToolSet`	`map[string]types.Tool`
`StopWhen`	`[]ai.StopCondition`
`Telemetry`	`*ai.TelemetrySettings`
`ActiveTools`	`[]string`
`RuntimeContext`	`interface{}`
`ToolsContext`	`map[string]interface{}`
`Include`	`*ai.IncludeOptions`
`ExperimentalSandbox`	`interface{}`
`ExperimentalRefineToolInput`	`map[string]ai.ToolInputRefiner`
`RepairToolCall`	`ai.ToolCallRepairFunction`	RepairToolCall attempts to repair tool calls that fail to parse.
`ExperimentalRepairToolCall`	`ai.ToolCallRepairFunction`	ExperimentalRepairToolCall is a deprecated alias for RepairToolCall. Deprecated: use RepairToolCall.
`ExperimentalToolApprovalSecret`	`[]byte`	ExperimentalToolApprovalSecret overrides the agent's approval secret.
`MaxRetries`	`*int`	MaxRetries overrides the agent's MaxRetries for this call.
`Timeout`	`*ai.TimeoutConfig`	Timeout overrides the agent's Timeout for this call.
`ExperimentalDownload`	`ai.DownloadFunction`	ExperimentalDownload overrides the agent's ExperimentalDownload for this call.
`ExperimentalTransform`	`[]ai.StreamTransformFunc`	ExperimentalTransform is an ordered list of transforms applied to raw model stream chunks before they reach OnChunk or the returned WorkflowStreamResult, matching TS WorkflowAgent's `experimental_transform` stream option (hash 165455d). Previously declared-but-unused in TS; this forwards it through to the underlying ai.StreamText call so it actually runs.
`OnChunk`	`func(chunk provider.StreamChunk)`
`OnStart`	`StartCallback`
`OnStepStart`	`StepStartCallback`
`OnToolExecutionStart`	`ToolExecutionStartCallback`
`OnToolExecutionEnd`	`ToolExecutionEndCallback`
`OnStepEnd`	`StepEndCallback`
`OnStepFinish`	`StepFinishCallback`	Deprecated: use OnStepEnd.
`OnEnd`	`EndCallback`
`OnFinish`	`FinishCallback`	Deprecated: use OnEnd.
`OnError`	`ErrorCallback`
`OnAbort`	`AbortCallback`

Results

workflow.WorkflowResult is the final non-streaming result. IsLoopFinished() reports whether the run ended naturally.

Field	Type	Description
(embedded)	`*agent.AgentResult`	Embedded.

workflow.WorkflowStreamResult wraps the streaming result.

Field	Type	Description
(embedded)	`*ai.StreamTextResult`	Embedded.

Hooks and callbacks

The hook and callback function types mirror the ToolLoopAgent ones.

Type	Description
`workflow.PrepareStepHook`	Mutates per-step options using the current history.
`workflow.PrepareCallHook`	Mutates per-step call options before model invocation.
`workflow.FilterActiveToolsHook`	Reduces the available tools for a step.
`workflow.LanguageModelCallOptions`	The per-step call configuration, as in `ToolLoopAgent`.
`workflow.StartCallback`	Fires once before the first step.
`workflow.StepStartCallback`	Fires before each model step.
`workflow.StepEndCallback`, `workflow.StepFinishCallback`	Fire after each completed step.
`workflow.ToolExecutionStartCallback`, `workflow.ToolExecutionEndCallback`	Fire around local tool execution.
`workflow.EndCallback`, `workflow.FinishCallback`	Fire once after the run completes.
`workflow.ErrorCallback`	Fires when execution returns an error.
`workflow.AbortCallback`	Fires when the context cancels the run.

Field	Type	Description
`StepNumber`	`int`
`System`	`string`
`AllowSystemInMessages`	`bool`
`Messages`	`[]types.Message`
`Tools`	`[]types.Tool`
`ToolChoice`	`types.ToolChoice`
`CallOptions`	`interface{}`
`Temperature`	`*float64`
`MaxTokens`	`*int`
`TopP`	`*float64`
`TopK`	`*int`
`FrequencyPenalty`	`*float64`
`PresencePenalty`	`*float64`
`StopSequences`	`[]string`
`Seed`	`*int`
`Headers`	`map[string]string`
`Reasoning`	`*types.ReasoningLevel`
`SendReasoning`	`*bool`
`ProviderOptions`	`map[string]interface{}`
`RuntimeContext`	`interface{}`
`ToolsContext`	`map[string]interface{}`
`ExperimentalSandbox`	`interface{}`
`PreviousSteps`	`[]types.StepResult`
`AccumulatedUsage`	`types.Usage`
`CustomData`	`interface{}`
`StopWhen`	`[]ai.StopCondition`	StopWhen, ActiveTools and ExperimentalDownload mirror TS prepareCall's per-call stopWhen/activeTools/download settings parity (d56638a): a PrepareCall/PrepareStep hook can read the current effective value here and mutate it to override the call.
`ActiveTools`	`[]string`
`ExperimentalDownload`	`ai.DownloadFunction`
`MaxRetries`	`*int`	MaxRetries and Timeout mirror TS's `maxRetries`/`abortSignal` prepareCall parity (419adc7). Timeout is the Go stand-in for TS's AbortSignal.
`Timeout`	`*ai.TimeoutConfig`
`InitialInstructions`	`string`	InitialInstructions and InitialMessages are the original (unmutated) instructions/messages the call was invoked with, matching TS prepareCall's initial-inputs parity (b666f57). They are read-only: a hook should mutate System/Messages to change what is sent, not these.
`InitialMessages`	`[]types.Message`

Iterating steps

workflow.StreamTextIterator iterates the step results of a run. Next(ctx) returns the next *types.StepResult and io.EOF when the steps are exhausted. Close() marks the iterator closed.

Constructor	Description
`workflow.NewStreamTextIterator(steps []types.StepResult)`	Iterates a slice you already have.
`workflow.NewStreamTextIteratorFromChannel(ch <-chan types.StepResult)`	Iterates live steps from a channel.
`workflow.NewStreamTextIteratorFromResult(result *WorkflowResult)`	Iterates the steps of a result.

Serializable tools

A durable run cannot persist a Go function. These helpers carry the tool definitions across an execution boundary, and you attach Execute functions again by name afterward.

Function	Description
`workflow.SerializeToolSet(tools []types.Tool) (map[string]SerializableToolDef, error)`	Converts tools to a JSON-safe map keyed by name.
`workflow.ResolveSerializableTools(defs map[string]SerializableToolDef) []types.Tool`	Rebuilds non-executable tool descriptors.
`workflow.ValidateSerializableToolInput(def SerializableToolDef, input interface{}) (interface{}, error)`	Validates input against the serialized schema. It applies schema defaults first, and returns the defaulted value. Pass that value to the tool, not the raw input.
`workflow.MarshalSchema(schema interface{}) (map[string]interface{}, error)`	Converts a JSON-serializable schema to a map.
`workflow.UnmarshalSchema(data map[string]interface{}) (interface{}, error)`	Rebuilds a schema as a generic JSON value.

Field	Type	Description
`Name`	`string`
`Description`	`string`
`Title`	`string`
`Parameters`	`map[string]interface{}`
`InputSchema`	`map[string]interface{}`
`Type`	`string`
`ID`	`string`
`Args`	`map[string]interface{}`
`Strict`	`*bool`
`ProviderExecuted`	`bool`
`IsProviderExecuted`	`bool`
`SupportsDeferredResults`	`bool`
`InputExamples`	`[]types.ToolInputExample`
`ProviderMetadata`	`map[string]interface{}`

Chat transports

WorkflowChatTransport

workflow.WorkflowChatTransport is a client-side ai.ChatTransport. It POSTs the message history to a workflow chat endpoint and reads the response as a stream of UI message chunks. When the response ends without a finish chunk, for example after a network drop or a function timeout, it reconnects with a GET to <api>/<runId>/stream?startIndex=N. It also repairs UI message stream framing and, on a resume with a negative start index, drops deltas and ends whose start fell outside the resumed window.

func NewWorkflowChatTransport(opts WorkflowChatTransportOptions) *WorkflowChatTransport

SendMessages(ctx, ai.ChatTransportSendMessagesRequest) and ReconnectToStream(ctx, ai.ChatTransportReconnectToStreamRequest) implement ai.ChatTransport. See Stream transport helpers.

Field	Type	Description
`API`	`string`	API is the chat endpoint. Defaults to "/api/chat".
`HTTPClient`	`*http.Client`	HTTPClient is used for both the initial POST and any reconnect GETs. Defaults to http.DefaultClient.
`OnChatSendMessage`	`func(resp *http.Response, req ai.ChatTransportSendMessagesRequest) error`	OnChatSendMessage is invoked after the initial POST completes, useful for inspecting response headers or tracking chat history.
`OnChatEnd`	`func(WorkflowChatTransportEndEvent) error`	OnChatEnd is invoked once, after a "finish" chunk is observed.
`MaxConsecutiveErrors`	`int`	MaxConsecutiveErrors bounds reconnect attempts. Defaults to 3.
`InitialStartIndex`	`int`	InitialStartIndex is the default startIndex used by ReconnectToStream when it is called directly (not as part of a SendMessages recovery). Negative values are tail-relative (e.g. -10 reads the last 10 chunks), useful for resuming a chat UI after a page refresh without replaying the whole conversation. Defaults to 0 (replay from the beginning).
`PrepareSendMessagesRequest`	`func(ai.ChatTransportSendMessagesRequest) (PreparedChatRequest, error)`	PrepareSendMessagesRequest customizes the API endpoint, body, and headers used for the initial POST.
`PrepareReconnectToStreamRequest`	`func(WorkflowChatTransportReconnectContext) (PreparedChatRequest, error)`	PrepareReconnectToStreamRequest customizes the API endpoint and headers used for reconnect GETs.

Field	Type	Description
`ChatID`	`string`
`MessageID`	`string`
`Trigger`	`string`
`Messages`	`interface{}`
`Body`	`map[string]interface{}`
`Headers`	`map[string]string`

Field	Type	Description
`RunID`	`string`
`ChatID`	`string`
`StartIndex`	`int`
`Headers`	`map[string]string`

workflow.WorkflowChatTransportReconnectContext is passed to PrepareReconnectToStreamRequest. workflow.WorkflowChatTransportEndEvent is passed to OnChatEnd. workflow.ChatEndEvent is the equivalent event for the multiplexer's OnChatEnd. It carries ChatID, ChunkIndex, RunID and the SSE Events.

Field	Type	Description
`ChatID`	`string`
`ChunkIndex`	`int`

WorkflowRunMultiplexer

workflow.WorkflowRunMultiplexer is a Go-only server and client helper that predates WorkflowChatTransport. It serves run-scoped SSE and resume handlers. Its client helpers return raw SSE events, not UI message chunks, so it does not implement ai.ChatTransport. For new client code, use WorkflowChatTransport.

func NewWorkflowRunMultiplexer(opts ...WorkflowRunMultiplexerOptions) *WorkflowRunMultiplexer

Method	Description
`ServeHTTP(w, r)`	Starts a new run stream and emits lifecycle events.
`Resume(runID string) http.Handler`	Returns a handler that attaches an SSE reader to a run in progress.
`SendMessages(ctx, SendMessagesOptions) ([]*streaming.SSEEvent, error)`	POSTs chat messages and returns parsed SSE events.
`ReconnectToStream(ctx, ReconnectToStreamOptions) ([]*streaming.SSEEvent, error)`	GETs the API to resume a run-scoped SSE stream.

Field	Type	Description
`API`	`string`
`HTTPClient`	`*http.Client`
`MaxConsecutiveErrors`	`int`
`InitialStartIndex`	`int`
`OnChatSendMessage`	`func(*http.Response, SendMessagesOptions) error`
`OnChatEnd`	`func(ChatEndEvent) error`
`PrepareSendMessagesRequest`	`func(SendMessagesOptions) (PreparedChatRequest, error)`
`PrepareReconnectToStreamRequest`	`func(ReconnectToStreamOptions) (PreparedChatRequest, error)`

Field	Type	Description
`API`	`string`
`Body`	`map[string]interface{}`
`Headers`	`map[string]string`

Durable harness runner

These functions run a harness agent across process executions. Each execution returns a serializable workflow.HarnessWorkflowState. Your durable-workflow runtime stores it as the checkpoint, and you pass it to the next execution.

Function	Description
`workflow.CreateHarnessWorkflowState(HarnessWorkflowInput) HarnessWorkflowState`	Builds the initial state for one user turn.
`workflow.RunHarnessAgent(ctx, RunHarnessAgentOptions) (HarnessWorkflowState, error)`	Runs one durable execution. It resumes or starts the session and streams the turn's chunks to `Writable`. When `TimeSliceSeconds` is positive, it races the turn against that budget and suspends the turn when the slice ends.
`workflow.RunHarnessAgentTimeSlice(ctx, RunHarnessAgentTimeSliceOptions) (HarnessWorkflowState, error)`	Runs one time-boxed slice. When the slice ends before the turn, the status is `ready_for_next_step`.
`workflow.RunHarnessAgentStep(ctx, RunHarnessAgentStepOptions) (HarnessWorkflowState, error)`	Runs until the next step boundary. Set `StopWhen` on the agent, for example `ai.IsStepCount(1)`.
`workflow.RunHarnessAgentSlice(ctx, RunHarnessAgentSliceOptions)`	Deprecated alias of `RunHarnessAgentTimeSlice` that reports `timed_out` where the new function reports `ready_for_next_step`.
`workflow.FinalizeHarnessWorkflow(state) (HarnessWorkflowFinalResult, error)`	Collapses a terminal state into its result. It returns an error if the run failed.

workflow.DefaultTimeSliceSeconds is 750. A Vercel Fluid Compute instance is recycled at about 800 seconds, so a 750-second slice leaves time for the next execution to reattach to the sandbox that is still running.

Status

Constant	Value	Description
`HarnessWorkflowStatusNotStarted`	`"not_started"`	HarnessWorkflowStatusNotStarted is the fresh state before any execution has run.
`HarnessWorkflowStatusReadyForNextStep`	`"ready_for_next_step"`	HarnessWorkflowStatusReadyForNextStep means the turn remains unfinished and ContinueFrom carries the cursor for the next execution.
`HarnessWorkflowStatusAwaitingToolApproval`	`"awaiting_tool_approval"`	HarnessWorkflowStatusAwaitingToolApproval means the turn emitted one or more tool approval/result requests and ContinueFrom carries the suspended turn.
`HarnessWorkflowStatusFinished`	`"finished"`	HarnessWorkflowStatusFinished means the agent turn completed on its own; FinalResult is set.
`HarnessWorkflowStatusFailed`	`"failed"`	HarnessWorkflowStatusFailed means the turn errored; Error is set.
`HarnessWorkflowStatusTimedOut`	`"timed_out"`	HarnessWorkflowStatusTimedOut is returned by the deprecated RunHarnessAgentSlice in place of HarnessWorkflowStatusReadyForNextStep. Deprecated: use HarnessWorkflowStatusReadyForNextStep.

Types

workflow.HarnessWorkflowAgent is the subset of *harness.Agent the runner drives: HasOutput, CreateSession, Stream and ContinueStream. *harness.Agent satisfies it.

Field	Type	Description
`Prompt`	`harness.Prompt`
`Messages`	`[]types.Message`
`SessionID`	`string`
`ResumeFrom`	`*harness.ResumeSessionState`
`ContinueFrom`	`*harness.ContinueTurnState`

Field	Type	Description
`SessionID`	`string`	SessionID is the stable harness session id; doubles as the sandbox name across processes.
`Prompt`	`harness.Prompt`	Prompt is the new user turn for this run. Sent once, on the execution that starts the turn.
`Messages`	`[]types.Message`	Messages carries full model messages for continuing a suspended approval turn (e.g. tool-approval-response content). When non-nil, the next execution sends these instead of Prompt/ContinueFrom.
`Status`	`HarnessWorkflowStatus`
`ResumeFrom`	`*harness.ResumeSessionState`	ResumeFrom carries resume coordinates for the next user turn.
`ContinueFrom`	`*harness.ContinueTurnState`	ContinueFrom carries continuation coordinates for this run's current suspended turn.
`StreamContext`	`*HarnessWorkflowStreamContext`
`FinalResult`	`*HarnessWorkflowFinalResult`
`Error`	`string`

Field	Type	Description
`SessionID`	`string`
`FinishReason`	`string`
`Usage`	`*HarnessWorkflowUsageSummary`
`Output`	`any`	Output is the agent's parsed and schema-validated output when the agent has an output specification (HarnessWorkflowAgent.HasOutput).

Field	Type	Description
`Agent`	`HarnessWorkflowAgent`
`State`	`HarnessWorkflowState`
`SandboxSession`	`providerutils.SandboxSession`	SandboxSession, when set, is forwarded to HarnessWorkflowAgent. CreateSession as a caller-owned sandbox (harness.CreateSessionOptions. SandboxSession) instead of letting the agent's own SandboxProvider create/resume one. Mirrors TS `RunHarnessAgentOptions.sandboxSession`.
`TimeSliceSeconds`	`float64`	TimeSliceSeconds is the wall-clock budget for this execution. Zero means no time slice: the run continues until the harness's own turn (or, with a StopWhen-configured agent, step) boundary.
`DestroyOnFinish`	`bool`	DestroyOnFinish controls whether to destroy the sandbox when the run finishes or fails. Defaults to false: the session is parked and a fresh resume state is returned in ResumeFrom, so the next user turn reattaches to the same conversation (multi-turn chat). Set true for a one-shot run that should release the sandbox when the run ends.
`Writable`	`HarnessWorkflowWriter`	Writable is where to write the turn's UI-message chunks. Required — TS's default resolveWorkflowWritable() (a Workflow DevKit getWritable()) has no Go equivalent.

Field	Type	Description
`Agent`	`HarnessWorkflowAgent`
`State`	`HarnessWorkflowState`
`SandboxSession`	`providerutils.SandboxSession`
`TimeSliceSeconds`	`float64`	TimeSliceSeconds defaults to DefaultTimeSliceSeconds when zero.
`DestroyOnFinish`	`bool`
`Writable`	`HarnessWorkflowWriter`

Field	Type	Description
`Agent`	`HarnessWorkflowAgent`
`State`	`HarnessWorkflowState`
`SandboxSession`	`providerutils.SandboxSession`
`DestroyOnFinish`	`bool`
`Writable`	`HarnessWorkflowWriter`

Field	Type	Description
`Agent`	`HarnessWorkflowAgent`
`State`	`HarnessWorkflowState`
`SandboxSession`	`providerutils.SandboxSession`
`TimeSliceSeconds`	`float64`
`SliceTimeoutSeconds`	`float64`	SliceTimeoutSeconds is used when TimeSliceSeconds is zero. Deprecated: use TimeSliceSeconds.
`DestroyOnFinish`	`bool`
`Writable`	`HarnessWorkflowWriter`

workflow.HarnessWorkflowStreamContext is the serializable subset of in-flight UI message state carried across an execution boundary. workflow.HarnessWorkflowActiveToolInput is a tool input that was partly streamed when the execution ended. workflow.HarnessWorkflowUsageSummary is a minimal token usage summary.

Field	Type	Description
`ActiveTextParts`	`map[string]ai.UIMessageChunk`
`ActiveReasoningParts`	`map[string]ai.UIMessageChunk`
`ActiveToolInputs`	`map[string]HarnessWorkflowActiveToolInput`
`PendingToolInputs`	`map[string]ai.UIMessageChunk`

Field	Type	Description
`InputTokens`	`*int64`
`OutputTokens`	`*int64`

Writer

workflow.HarnessWorkflowWriter receives the UI message chunks of one execution:

type HarnessWorkflowWriter interface {
	Write(chunk ai.UIMessageChunk) error
	Close() error
}

Write is called once per chunk, in order. Close is called only when the run reaches finished. The other statuses leave the writer open because a later execution keeps writing, or the failure propagates. workflow.NewChanHarnessWorkflowWriter(ch) returns a *workflow.ChanHarnessWorkflowWriter that forwards every chunk to ch and closes ch on Close.

WorkflowAgent​

WorkflowGenerateOptions​

WorkflowStreamOptions​

Results​

Hooks and callbacks​

Iterating steps​

Serializable tools​

Chat transports​

WorkflowChatTransport​

WorkflowRunMultiplexer​

Durable harness runner​

Status​

Types​

Writer​