ToolModelMessage

Namespace: Vercel.AI.Provider

public sealed class ToolModelMessage : ModelMessage

A tool result fed back to the model.

Inheritance: object → ModelMessage

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Constructors

ToolModelMessage(IReadOnlyList<ToolModelMessage>)

public ToolModelMessage(IReadOnlyList<ToolModelMessage> results)

Creates one tool message that carries several tool results, as upstream does for the calls of one step. Its single-result members describe the first result.

Parameters

Name	Type	Description
results	IReadOnlyList<ToolModelMessage>

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ToolModelMessage(string, string, IReadOnlyList<UserContentPart>, JsonElement?)

public ToolModelMessage(string toolCallId, string toolName, IReadOnlyList<UserContentPart> content, JsonElement? providerMetadata = null)

Creates a tool result whose output is a list of text and file parts, as upstream output: { type: 'content' }. OutputType is json and OutputJson is the JSON text of the parts, so a provider that does not read OutputContent sends the stringified parts, as upstream does by default.

Parameters

Name	Type	Description
toolCallId	string
toolName	string
content	IReadOnlyList<UserContentPart>
providerMetadata	JsonElement?

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ToolModelMessage(string, string, string, bool, JsonElement?)

public ToolModelMessage(string toolCallId, string toolName, string outputJson, bool isError, JsonElement? providerMetadata = null)

Creates a tool result message. The output type comes from <code class=“paramref”>isError</code> and from whether <code class=“paramref”>outputJson</code> is valid JSON.

Parameters

Name	Type	Description
toolCallId	string
toolName	string
outputJson	string
isError	bool
providerMetadata	JsonElement?

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ToolModelMessage(string, string, string?, bool, string?, JsonElement?)

public ToolModelMessage(string toolCallId, string toolName, string? outputJson, bool isError, string? outputType, JsonElement? providerMetadata = null)

Creates a tool result message. <code class=“paramref”>outputType</code> is text, json, error-text, error-json, or execution-denied. When it is null, the type comes from <code class=“paramref”>isError</code> and from whether <code class=“paramref”>outputJson</code> is valid JSON. When it is set, it decides IsError and <code class=“paramref”>isError</code> is ignored. For execution-denied, <code class=“paramref”>outputJson</code> is the reason, or null for none.

Parameters

Name	Type	Description
toolCallId	string
toolName	string
outputJson	string
isError	bool
outputType	string
providerMetadata	JsonElement?

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Properties

IsError

public bool IsError { get; }

Whether the tool failed.

Value: bool

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MessageProviderOptions

public IReadOnlyDictionary<string, JsonElement>? MessageProviderOptions { get; init; }

Provider options of the whole tool message, such as an Amazon Bedrock cachePoint added after all its results.

Value: IReadOnlyDictionary<string, JsonElement>

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OutputContent

public IReadOnlyList<UserContentPart>? OutputContent { get; }

Text and file parts of a multi-part output, or null for a single value. OutputJson holds the same parts as JSON text.

Value: IReadOnlyList<UserContentPart>

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OutputJson

public string OutputJson { get; }

JSON result. For text and error-text it is the text itself. For execution-denied it is the reason, or empty for none.

Value: string

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OutputProviderOptions

public JsonElement? OutputProviderOptions { get; init; }

Provider options set on the tool output itself rather than on the tool result, such as an OpenAI promptCacheBreakpoint.

Value: JsonElement?

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OutputType

public string OutputType { get; }

Output type: text, json, error-text, error-json, or execution-denied.

Value: string

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ProviderMetadata

public JsonElement? ProviderMetadata { get; }

Provider metadata carried on this tool result, such as a thought signature.

Value: JsonElement?

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ProviderOptions

public IReadOnlyDictionary<string, JsonElement>? ProviderOptions { get; init; }

Provider options set on this tool result, such as an Amazon Bedrock cachePoint.

Value: IReadOnlyDictionary<string, JsonElement>

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Results

public IReadOnlyList<ToolModelMessage> Results { get; }

The tool results this message carries, one per executed call. A single-result message lists itself.

Value: IReadOnlyList<ToolModelMessage>

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ToolCallId

public string ToolCallId { get; }

Matching tool call id.

Value: string

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ToolName

public string ToolName { get; }

Tool name.

Value: string

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Methods

Flatten(IReadOnlyList<ModelMessage>)

public static IReadOnlyList<ModelMessage> Flatten(IReadOnlyList<ModelMessage> messages)

Splits grouped tool messages into one message per result, in order. Other messages pass through.

Parameters

Name	Type	Description
messages	IReadOnlyList<ModelMessage>

Returns: IReadOnlyList<ModelMessage>

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