Letta MCP Servers API is one of 41 APIs that Letta publishes on the APIs.io network, described by a machine-readable OpenAPI specification.
This API exposes 14 JSON Schema definitions.
Tagged areas include MCP Servers. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, pricing, a changelog, and 14 JSON Schemas.
This API exposes
10 operations
across 7 paths,
and defines 74 schemas.
It is described by OpenAPI 3.1.0, at version 1.0.0.
Requests are made against 3 base URLs: https://api.letta.com, https://app.letta.com, http://localhost:8283.
The identity and technical contract details declared by the specification.
JsonObjectResponseFormat
object
Response format for JSON object responses.
1 property
GoogleAIModelSettings
object
6 properties
Tool
object
Representation of a tool, which is a function that can be called by the agent.
18 properties
letta__schemas__mcp_server__ToolExecuteRequest
object
Request to execute a tool.
1 property
AgentEnvironmentVariable
object
10 properties
3 required
ChatGPTOAuthModelSettings
object
ChatGPT OAuth model configuration (uses ChatGPT backend API).
5 properties
TextResponseFormat
object
Response format for plain text responses.
1 property
ToolExecutionResult
object
6 properties
1 required
ToolCallDelta
object
3 properties
ConditionalToolRule
object
A ToolRule that conditionally maps to different child tools based on the output.
6 properties
2 required
MaxCountPerStepToolRule
object
Represents a tool rule configuration which constrains the total number of times this tool can be invoked in a single step.
4 properties
2 required
CreateStreamableHTTPMCPServer
object
Create a new Streamable HTTP MCP server
5 properties
1 required
NpmRequirement
object
2 properties
1 required
HTTPValidationError
object
1 property
ZAIThinking
object
Thinking configuration for ZAI GLM-4.5+ models.
2 properties
ContinueToolRule
object
Represents a tool rule configuration where if this tool gets called, it must continue the agent loop.
3 properties
1 required
CreateMCPServerRequest
object
Request to create a new MCP server with configuration.
2 properties
2 required
GoogleVertexModelSettings
object
6 properties
letta__schemas__mcp_server__UpdateStdioMCPServer
object
Update schema for Stdio MCP server - all fields optional
4 properties
2 required
CreateStdioMCPServer
object
Create a new Stdio MCP server
4 properties
2 required
RequiresApprovalToolRule
object
Represents a tool rule configuration which requires approval before the tool can be invoked.
3 properties
1 required
SGLangModelSettings
object
SGLang model configuration (OpenAI-compatible runtime with SGLang-specific parsing).
8 properties
SSEMCPServer
object
An SSE MCP server
7 properties
2 required
VectorDBProvider
string
Supported vector database providers for archival memory
AgentState
object
Representation of an agent's state. This is the state of the agent at a given time, and is persisted in the DB backend. The state has all the information neede…
45 properties
10 required
GroqModelSettings
object
Groq model configuration (OpenAI-compatible).
5 properties
BedrockModelSettings
object
AWS Bedrock model configuration.
5 properties
Identity
object
8 properties
5 required
AgentType
string
Enum to represent the type of agent.
CompactionSettings-Output
object
Configuration for conversation compaction / summarization. Per-model settings (temperature, max tokens, etc.) are derived from the default configuration for th…
7 properties
LLMConfig
object
Configuration for Language Model (LLM) connection and generation parameters. .. deprecated:: LLMConfig is deprecated and should not be used as an input or retu…
27 properties
3 required
Group
object
18 properties
4 required
UpdateMCPServerRequest
object
Request to update an existing MCP server configuration.
2 properties
1 required
StreamableHTTPMCPServer
object
A Streamable HTTP MCP server
7 properties
2 required
ToolCallNode
object
Typed child override for prefilled arguments. When used in a ChildToolRule, if this child is selected next, its args will be applied as prefilled arguments (ov…
2 properties
1 required
FileBlock
object
23 properties
4 required
Source
object
(Deprecated: Use Folder) Representation of a source, which is a collection of files and passages.
11 properties
2 required
Block
object
A Block represents a reserved section of the LLM's context window.
19 properties
1 required
RequiredBeforeExitToolRule
object
Represents a tool rule configuration where this tool must be called before the agent loop can exit.
3 properties
1 required
ZAIModelSettings
object
Z.ai (ZhipuAI) model configuration (OpenAI-compatible).
6 properties
GeminiThinkingConfig
object
2 properties
ValidationError
object
3 properties
3 required
IdentityType
string
Enum to represent the type of the identity.
ApprovalRequestMessage
object
A message representing a request for approval to call a tool (generated by the LLM to trigger tool execution). Args: id (str): The ID of the message date (date…
12 properties
3 required
OpenAIReasoning
object
1 property
Memory
object
Represents the in-context memory (i.e. Core memory) of the agent. This includes both the Block objects (labelled by sections), as well as tools to edit the blo…
5 properties
1 required
BasetenModelSettings
object
Baseten model configuration (OpenAI-compatible).
4 properties
InitToolRule
object
Represents the initial tool rule configuration.
4 properties
1 required
AnthropicModelSettings
object
9 properties
XAIModelSettings
object
xAI model configuration (OpenAI-compatible).
5 properties
ChildToolRule
object
A ToolRule represents a tool that can be invoked by the agent.
5 properties
2 required
AnthropicThinking
object
2 properties
IdentityPropertyType
string
Enum to represent the type of the identity property.
IdentityProperty
object
A property of an identity
3 properties
3 required
OpenRouterModelSettings
object
OpenRouter model configuration (OpenAI-compatible).
5 properties
ParentToolRule
object
A ToolRule that only allows a child tool to be called if the parent has been called.
4 properties
2 required
letta__schemas__mcp_server__UpdateStreamableHTTPMCPServer
object
Update schema for Streamable HTTP MCP server - all fields optional
5 properties
1 required
PipRequirement
object
2 properties
1 required
StdioMCPServer
object
A Stdio MCP server
6 properties
3 required
TerminalToolRule
object
Represents a terminal tool rule configuration where if this tool gets called, it must end the agent loop.
3 properties
1 required
EmbeddingConfig
object
Configuration for embedding model connection and processing parameters.
10 properties
3 required
ChatGPTOAuthReasoning
object
Reasoning configuration for ChatGPT OAuth models (GPT-5.x, o-series).
1 property
ToolCall
object
3 properties
3 required
letta__schemas__mcp_server__UpdateSSEMCPServer
object
Update schema for SSE MCP server - all fields optional
5 properties
1 required
DeepseekModelSettings
object
Deepseek model configuration (OpenAI-compatible).
5 properties
CreateSSEMCPServer
object
Create a new SSE MCP server
5 properties
1 required
AzureModelSettings
object
Azure OpenAI model configuration (OpenAI-compatible).
5 properties
TogetherModelSettings
object
Together AI model configuration (OpenAI-compatible).
5 properties
JsonSchemaResponseFormat
object
Response format for JSON schema-based responses.
2 properties
1 required
OpenAIModelSettings
object
7 properties
The full machine-readable OpenAPI contract behind this narrative.
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