Vellum AI Execute Workflow Stream API
The Execute Workflow Stream API from Vellum AI — 1 operation(s) for execute workflow stream.
Vellum AI Execute Workflow Stream API is one of 23 APIs that Vellum AI publishes on the APIs.io network, described by a machine-readable OpenAPI specification.
Tagged areas include Execute Workflow Stream. The published artifact set on APIs.io includes an OpenAPI specification.
This API exposes 1 operation across 1 path, and defines 227 schemas. It is described by OpenAPI 3.2.0, at version 1.0.0.
Requests are made against 3 base URLs: https://predict.vellum.ai, https://api.vellum.ai, https://documents.vellum.ai.
1 operations
1 paths
227 schemas
1 POST
Metadata
The identity and technical contract details declared by the specification.
Authentication & Security 1
Vellum AI Execute Workflow Stream API declares
1 security scheme
for authenticating requests.
An API key is passed in the header as X-API-KEY (default).
Paths & Operations 1
Across 1 path, the API surfaces 1 operation — 1 POST. Each is listed below with its method, path, parameters, and response codes.
Execute Workflow Stream 1
POST
/v1/execute-workflow-stream
Execute Workflow Stream
Schemas 227
The contract defines 227 schemas that model the data the API accepts and returns. The most detailed are StreamingWorkflowNodeResultEvent (9 properties), FulfilledWorkflowNodeResultEvent (9 properties), ExecuteWorkflowStreamRequest (9 properties), RejectedWorkflowNodeResultEvent (8 properties). Each schema is shown below with its type and property counts.
TerminalNodeNumberResult
object
4 properties
3 required
NodeInputCompiledAudioValue
object
4 properties
4 required
WorkflowOutputImage
object
An image output from a Workflow execution.
4 properties
4 required
VellumVideo
object
2 properties
1 required
ArrayChatMessageContentRequest
object
A list of chat message content items.
2 properties
2 required
StringVellumValue
object
A value representing a string.
2 properties
2 required
TerminalNodeSearchResultsResult
object
4 properties
3 required
ChatMessageRole
string
SYSTEM - System ASSISTANT - Assistant USER - User FUNCTION - Function
WorkflowRequestImageInputRequest
object
The input for an image variable in a Workflow.
3 properties
3 required
WorkflowResultEventState
string
INITIATED - Initiated STREAMING - Streaming FULFILLED - Fulfilled REJECTED - Rejected PENDING - Pending
PdfEnum
string
NodeInputCompiledErrorValue
object
4 properties
4 required
CodeExecutionNodeStringResult
object
3 properties
3 required
TemplatingNodeStringResult
object
3 properties
3 required
TemplatingNodeNumberResult
object
3 properties
3 required
TemplatingEnum
string
ExecutionDocumentVellumValue
object
A base Vellum primitive value representing a document.
4 properties
4 required
SearchNodeResult
object
A Node Result Event emitted from a Search Node.
2 properties
2 required
ArrayVellumValue
object
A value representing an array of Vellum variable values.
2 properties
2 required
CodeExecutionNodeFunctionCallResult
object
3 properties
3 required
WorkflowRequestAudioInputRequest
object
The input for an audio variable in a Workflow.
3 properties
3 required
WorkflowExpandMetaRequest
object
3 properties
ArrayChatMessageContentItemRequest
ExecutionChatHistoryVellumValue
object
A value representing Chat History.
4 properties
4 required
MapEnum
string
SecretEnum
string
SearchResultMetaSource
NodeOutputCompiledNumberValue
object
An output returned by a node that is of type NUMBER.
4 properties
3 required
CodeExecutionNodeNumberResult
object
3 properties
3 required
InitiatedWorkflowNodeResultEvent
object
An event that indicates that the node has initiated its execution.
8 properties
5 required
JsonVellumValue
object
A value representing a JSON object.
2 properties
2 required
ExecutionImageVellumValue
object
A base Vellum primitive value representing an image.
4 properties
4 required
VellumVideoRequest
object
2 properties
1 required
SearchResult
object
5 properties
4 required
ApiEnum
string
ErrorVellumValue
object
A value representing an Error.
2 properties
2 required
VideoEnum
string
CodeExecutionNodeArrayResult
object
3 properties
3 required
SearchResultsEnum
string
WorkflowNodeResultEvent
WorkflowRequestVideoInputRequest
object
The input for a video variable in a Workflow.
3 properties
3 required
NodeInputVariableCompiledValue
FunctionCallChatMessageContent
object
A function call value that is used in a chat message.
2 properties
2 required
TerminalNodeJsonResult
object
4 properties
3 required
CodeExecutionNodeSearchResultsResult
object
3 properties
3 required
WorkflowResultEventOutputDataJSON
object
A JSON output streamed from a Workflow execution.
7 properties
5 required
ExecuteWorkflowStreamRequest
object
The request to stream a Workflow Deployment execution.
9 properties
1 required
VellumDocumentRequest
object
2 properties
1 required
VellumImageRequest
object
2 properties
1 required
Price
object
2 properties
2 required
RejectedWorkflowNodeResultEvent
object
An event that indicates that the node has rejected its execution.
8 properties
6 required
MergeNodeResult
object
A Node Result Event emitted from a Merge Node.
2 properties
2 required
TemplatingNodeChatHistoryResult
object
3 properties
3 required
ChatMessageContentRequest
ChatMessageRequest
object
5 properties
1 required
WorkflowResultEventOutputDataError
object
An Error output streamed from a Workflow execution.
7 properties
5 required
NumberVellumValue
object
A value representing a number.
2 properties
2 required
WorkflowOutputDocument
object
A document output from a Workflow execution.
4 properties
4 required
NodeOutputCompiledValue
MergeEnum
string
ImageChatMessageContentRequest
object
An image value that is used in a chat message.
2 properties
2 required
SearchNodeResultData
object
4 properties
3 required
ArrayChatMessageContentItem
ErrorEnum
string
WorkflowOutput
PromptEnum
string
NodeInputCompiledChatHistoryValue
object
4 properties
4 required
TerminalNodeErrorResult
object
4 properties
3 required
VellumErrorCodeEnum
string
INVALIDREQUEST - INVALIDREQUEST INVALIDINPUTS - INVALIDINPUTS PROVIDERERROR - PROVIDERERROR PROVIDERCREDENTIALSUNAVAILABLE - PROVIDERCREDENTIALSUNAVAILABLE INT…
VideoVellumValue
object
A base Vellum primitive value representing a video.
2 properties
2 required
NodeOutputCompiledThinkingValue
object
An output returned by a node that is of type THINKING.
4 properties
3 required
TemplatingNodeResultData
object
1 property
1 required
RejectedEnum
string
StringChatMessageContentRequest
object
A string value that is used in a chat message.
2 properties
2 required
WorkflowResultEventOutputDataFunctionCall
object
A Function Call output returned from a Workflow execution.
7 properties
5 required
ChatMessage
object
5 properties
1 required
VellumValue
MergeNodeResultData
object
1 property
WorkflowOutputChatHistory
object
A chat history output from a Workflow execution.
4 properties
4 required
CodeExecutionEnum
string
ExecutionVideoVellumValue
object
A base Vellum primitive value representing a video.
4 properties
4 required
AudioVellumValue
object
A base Vellum primitive value representing audio.
2 properties
2 required
TerminalNodeStringResult
object
4 properties
3 required
WorkflowResultEventOutputDataNumber
object
A number output streamed from a Workflow execution.
7 properties
5 required
WorkflowResultEventOutputDataChatHistory
object
A Chat History output streamed from a Workflow execution.
7 properties
5 required
ArrayEnum
string
NodeOutputCompiledErrorValue
object
An output returned by a node that is of type ERROR.
4 properties
3 required
ExecutionJsonVellumValue
object
A value representing a JSON object.
4 properties
4 required
TerminalNodeChatHistoryResult
object
4 properties
3 required
NodeInputCompiledVideoValue
object
4 properties
4 required
ExecutionErrorVellumValue
object
A value representing an Error.
4 properties
4 required
TemplatingNodeResult
object
A Node Result Event emitted from a Templating Node.
2 properties
2 required
PromptNodeResultData
object
6 properties
1 required
TemplatingNodeSearchResultsResult
object
3 properties
3 required
ConditionalNodeResultData
object
1 property
CodeExecutionNodeResultData
object
2 properties
1 required
WorkflowRequestJSONInputRequest
object
The input for a JSON variable in a Workflow.
3 properties
3 required
NodeOutputCompiledArrayValue
object
An output returned by a node that is of type ARRAY.
4 properties
3 required
PdfSearchResultMetaSource
object
The source of a search result from a PDF document.
3 properties
3 required
TemplatingNodeResultOutput
WorkflowNodeResultEventState
string
INITIATED - INITIATED STREAMING - STREAMING FULFILLED - FULFILLED REJECTED - REJECTED
WorkflowResultEventOutputDataSearchResults
object
A Search Results output streamed from a Workflow execution.
7 properties
5 required
PromptNodeExecutionMeta
object
The subset of the metadata tracked by Vellum during prompt execution that the request opted into with expandmeta.
3 properties
WorkflowExecutionEventErrorCode
string
WORKFLOWINITIALIZATION - WORKFLOWINITIALIZATION WORKFLOWCANCELLED - WORKFLOWCANCELLED WORKFLOWTIMEOUT - WORKFLOWTIMEOUT PROVIDERCREDENTIALSUNAVAILABLE - PROVID…
WorkflowResultEventOutputDataArray
object
An Array output returned from a Workflow execution.
7 properties
5 required
IterationStateEnum
string
INITIATED - INITIATED FULFILLED - FULFILLED REJECTED - REJECTED
ArrayChatMessageContent
object
A list of chat message content items.
2 properties
2 required
FunctionCallChatMessageContentValueRequest
object
The final resolved function call value.
3 properties
2 required
VellumAudio
object
2 properties
1 required
NodeEnum
string
CodeExecutionNodeResult
object
A Node Result Event emitted from a Code Execution Node.
2 properties
2 required
WorkflowResultEvent
object
7 properties
4 required
WorkflowOutputSearchResults
object
A search results output from a Workflow execution.
4 properties
4 required
NodeInputCompiledDocumentValue
object
4 properties
4 required
ConditionalNodeResult
object
A Node Result Event emitted from a Conditional Node.
2 properties
2 required
WorkflowExecutionNodeResultEvent
object
A NODE-level event emitted from the workflow's execution.
5 properties
3 required
CodeExecutionNodeChatHistoryResult
object
3 properties
3 required
WorkflowOutputFunctionCall
object
A function call output from a Workflow execution.
4 properties
4 required
NodeInputCompiledArrayValue
object
4 properties
4 required
WorkflowOutputArray
object
An array output from a Workflow execution.
4 properties
4 required
ExecutionThinkingVellumValue
object
A value representing Thinking mode output.
4 properties
4 required
FunctionCall
object
The final resolved function call value.
3 properties
2 required
WorkflowRequestNumberInputRequest
object
The input for a number variable in a Workflow.
3 properties
3 required
NodeOutputCompiledFunctionCallValue
object
An output returned by a node that is of type FUNCTIONCALL.
4 properties
3 required
NodeInputCompiledSecretValue
object
4 properties
4 required
WorkflowRequestChatHistoryInputRequest
object
The input for a chat history variable in a Workflow.
3 properties
3 required
DocumentEnum
string
FulfilledEnum
string
WorkflowRequestDocumentInputRequest
object
The input for a document variable in a Workflow.
3 properties
3 required
ChatMessageContent
WorkflowOutputError
object
An error output from a Workflow execution.
4 properties
4 required
UnitEnum
string
USD - USD
AudioChatMessageContent
object
An audio value that is used in a chat message.
2 properties
2 required
ApiNodeResult
object
A Node Result Event emitted from an API Node.
2 properties
2 required
WorkflowStreamEvent
WorkflowEventError
object
4 properties
2 required
FulfilledWorkflowNodeResultEvent
object
An event that indicates that the node has fulfilled its execution.
9 properties
6 required
ApiNodeResultData
object
6 properties
4 required
VellumAudioRequest
object
2 properties
1 required
SearchResultsVellumValue
object
A value representing Search Results.
2 properties
2 required
AudioChatMessageContentRequest
object
An audio value that is used in a chat message.
2 properties
2 required
FunctionCallChatMessageContentValue
object
The final resolved function call value.
3 properties
2 required
ChatHistoryEnum
string
SearchResultMeta
object
1 property
FunctionCallVellumValue
object
A value representing a Function Call.
2 properties
2 required
WorkflowRequestInputRequest
WorkflowOutputNumber
object
A number output from a Workflow execution.
4 properties
4 required
ExecuteWorkflowStreamErrorResponse
object
1 property
1 required
SubworkflowEnum
string
WorkflowOutputJSON
object
A JSON output from a Workflow execution.
4 properties
4 required
ExecutionFunctionCallVellumValue
object
A value representing a Function Call.
4 properties
4 required
SearchEnum
string
SubworkflowNodeResultData
object
1 property
NodeInputCompiledImageValue
object
4 properties
4 required
FunctionCallEnum
string
MapNodeResultData
object
2 properties
1 required
DocumentVellumValue
object
A base Vellum primitive value representing a document.
2 properties
2 required
TerminalEnum
string
WorkflowResultEventOutputData
VellumImage
object
2 properties
1 required
StreamingWorkflowNodeResultEvent
object
An event that indicates that the node has execution is in progress.
9 properties
5 required
NumberEnum
string
NodeOutputCompiledChatHistoryValue
object
An output returned by a node that is of type CHATHISTORY.
4 properties
3 required
VellumDocument
object
2 properties
1 required
ThinkingEnum
string
WorkflowNodeResultData
CodeExecutionNodeJsonResult
object
3 properties
3 required
TemplatingNodeArrayResult
object
3 properties
3 required
JsonEnum
string
WorkflowRequestStringInputRequest
object
The input for a string variable in a Workflow.
3 properties
3 required
WorkflowResultEventOutputDataString
object
A string output streamed from a Workflow execution.
7 properties
5 required
VellumSecret
object
1 property
1 required
VellumError
object
3 properties
2 required
StreamingEnum
string
TerminalNodeResult
object
A Node Result Event emitted from a Terminal Node.
2 properties
2 required
WorkflowEventErrorRawData
FunctionCallChatMessageContentRequest
object
A function call value that is used in a chat message.
2 properties
2 required
InitiatedEnum
string
ThinkingVellumValue
object
A value representing Thinking mode output.
2 properties
2 required
VideoChatMessageContentRequest
object
A video value that is used in a chat message.
2 properties
2 required
WorkflowOutputAudio
object
An audio output from a Workflow execution.
4 properties
4 required
ConditionalEnum
string
DocumentChatMessageContentRequest
object
A document value that is used in a chat message.
2 properties
2 required
TemplatingNodeJsonResult
object
3 properties
3 required
DocumentChatMessageContent
object
A document value that is used in a chat message.
2 properties
2 required
ImageChatMessageContent
object
An image value that is used in a chat message.
2 properties
2 required
PromptNodeResult
object
A Node Result Event emitted from a Prompt Node.
2 properties
2 required
ExecutionNumberVellumValue
object
A value representing a number.
4 properties
4 required
NodeInputCompiledFunctionCallValue
object
4 properties
4 required
NodeOutputCompiledJsonValue
object
An output returned by a node that is of type JSON.
4 properties
3 required
WorkflowExecutionEventType
string
NODE - NODE WORKFLOW - WORKFLOW
ChatHistoryVellumValue
object
A value representing Chat History.
2 properties
2 required
StringChatMessageContent
object
A string value that is used in a chat message.
2 properties
2 required
ImageVellumValue
object
A base Vellum primitive value representing an image.
2 properties
2 required
MetricEnum
string
TemplatingNodeErrorResult
object
3 properties
3 required
CodeExecutionNodeErrorResult
object
3 properties
3 required
NodeInputCompiledJsonValue
object
4 properties
4 required
MapNodeResult
object
A Node Result Event emitted from a Map Node.
2 properties
1 required
ExecutionSearchResultsVellumValue
object
A value representing Search Results.
4 properties
4 required
TerminalNodeFunctionCallResult
object
4 properties
3 required
SubworkflowNodeResult
object
A Node Result Event emitted from a Subworkflow Node.
2 properties
1 required
ExecutionAudioVellumValue
object
A base Vellum primitive value representing audio.
4 properties
4 required
NodeInputCompiledNumberValue
object
4 properties
4 required
NodeInputCompiledStringValue
object
4 properties
4 required
NodeInputCompiledSearchResultsValue
object
4 properties
4 required
TerminalNodeResultOutput
ImageEnum
string
ExecutionVellumValue
TerminalNodeArrayResult
object
4 properties
3 required
ExecutionStringVellumValue
object
A value representing a string.
4 properties
4 required
NodeOutputCompiledStringValue
object
An output returned by a node that is of type STRING.
4 properties
3 required
WorkflowExecutionWorkflowResultEvent
object
A WORKFLOW-level event emitted from the workflow's execution.
5 properties
3 required
WorkflowOutputVideo
object
A video output from a Workflow execution.
4 properties
4 required
WorkflowOutputString
object
A string output from a Workflow execution.
4 properties
4 required
CodeExecutionNodeResultOutput
TemplatingNodeFunctionCallResult
object
3 properties
3 required
TerminalNodeResultData
object
1 property
1 required
ExecutionArrayVellumValue
object
A value representing an array of Vellum variable values.
4 properties
4 required
WorkflowEnum
string
AudioEnum
string
NodeOutputCompiledSearchResultsValue
object
An output returned by a node that is of type SEARCHRESULTS.
4 properties
3 required
VideoChatMessageContent
object
A video value that is used in a chat message.
2 properties
2 required
StringEnum
string
SearchResultDocument
object
4 properties
1 required
MLModelUsage
object
7 properties
MetricNodeResult
object
A Node Result Event emitted from a Metric Node.
1 property
1 required
Specification
The full machine-readable OpenAPI contract behind this narrative.
Source
More from Vellum AI 12
Other APIs Vellum AI publishes across the network.
Vellum LLM Platform API
Vellum AI Subpackage Deployments API
Vellum AI Subpackage Document Indexes API
Vellum AI Subpackage Documents API
Vellum AI Subpackage Events API
Vellum AI Subpackage Folder Entities API
Vellum AI Subpackage Sandboxes API
Vellum AI Subpackage Test Suite Runs API
Vellum AI Subpackage Test Suites API
Vellum AI Subpackage Uploaded Files API
Vellum AI Subpackage Workflow Deployments API
Vellum AI Subpackage Workflow Executions API
#Execute Workflow Stream
Where this information came from
This is an independent, third-party profile of Vellum AI Execute Workflow Stream API, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
info@apievangelist.com
·
Read the full data-sourcing policy →
On a security or compliance team? Put security in the subject line and
you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.