> ## Documentation Index > Fetch the complete documentation index at: https://cognitio-agent.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Get message > Retrieve a specific message from a session by its message ID. ## OpenAPI ````yaml /openapi.json get /session/{sessionID}/message/{messageID} openapi: 3.1.1 info: title: cognitio description: cognitio api version: 1.0.0 servers: [] security: [] paths: /session/{sessionID}/message/{messageID}: get: summary: Get message description: Retrieve a specific message from a session by its message ID. operationId: session.message parameters: - in: query name: directory schema: type: string - in: query name: workspace schema: type: string - in: path name: sessionID schema: type: string pattern: ^ses.* required: true - in: path name: messageID schema: type: string pattern: ^msg.* required: true responses: '200': description: Message content: application/json: schema: type: object properties: info: $ref: '#/components/schemas/Message' parts: type: array items: $ref: '#/components/schemas/Part' required: - info - parts '400': description: Bad request content: application/json: schema: $ref: '#/components/schemas/BadRequestError' '404': description: Not found content: application/json: schema: $ref: '#/components/schemas/NotFoundError' x-codeSamples: - lang: js source: |- import { createCognitioClient } from "@cognitio/sdk const client = createCognitioClient() await client.session.message({ ... }) components: schemas: Message: anyOf: - $ref: '#/components/schemas/UserMessage' - $ref: '#/components/schemas/AssistantMessage' Part: anyOf: - $ref: '#/components/schemas/TextPart' - $ref: '#/components/schemas/SubtaskPart' - $ref: '#/components/schemas/ReasoningPart' - $ref: '#/components/schemas/FilePart' - $ref: '#/components/schemas/ToolPart' - $ref: '#/components/schemas/StepStartPart' - $ref: '#/components/schemas/StepFinishPart' - $ref: '#/components/schemas/SnapshotPart' - $ref: '#/components/schemas/PatchPart' - $ref: '#/components/schemas/AgentPart' - $ref: '#/components/schemas/RetryPart' - $ref: '#/components/schemas/CompactionPart' BadRequestError: type: object properties: data: {} errors: type: array items: type: object propertyNames: type: string additionalProperties: {} success: type: boolean const: false required: - data - errors - success NotFoundError: type: object properties: name: type: string const: NotFoundError data: type: object properties: message: type: string required: - message required: - name - data UserMessage: type: object properties: id: type: string pattern: ^msg.* sessionID: type: string pattern: ^ses.* role: type: string const: user time: type: object properties: created: type: number required: - created parentMessageID: type: string pattern: ^msg.* format: $ref: '#/components/schemas/OutputFormat' summary: type: object properties: title: type: string body: type: string diffs: type: array items: $ref: '#/components/schemas/SnapshotFileDiff' required: - diffs agent: type: string model: type: object properties: providerID: type: string modelID: type: string variant: type: string required: - providerID - modelID system: type: string tools: type: object propertyNames: type: string additionalProperties: type: boolean required: - id - sessionID - role - time - agent - model AssistantMessage: type: object properties: id: type: string pattern: ^msg.* sessionID: type: string pattern: ^ses.* role: type: string const: assistant time: type: object properties: created: type: number completed: type: number required: - created error: anyOf: - $ref: '#/components/schemas/ProviderAuthError' - $ref: '#/components/schemas/UnknownError' - $ref: '#/components/schemas/MessageOutputLengthError' - $ref: '#/components/schemas/MessageAbortedError' - $ref: '#/components/schemas/StructuredOutputError' - $ref: '#/components/schemas/ContextOverflowError' - $ref: '#/components/schemas/APIError' parentID: type: string pattern: ^msg.* parentMessageID: type: string pattern: ^msg.* modelID: type: string providerID: type: string mode: type: string agent: type: string path: type: object properties: cwd: type: string root: type: string required: - cwd - root summary: type: boolean cost: type: number tokens: type: object properties: total: type: number input: type: number output: type: number reasoning: type: number cache: type: object properties: read: type: number write: type: number required: - read - write required: - input - output - reasoning - cache structured: {} variant: type: string finish: type: string required: - id - sessionID - role - time - parentID - modelID - providerID - mode - agent - path - cost - tokens TextPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: text text: type: string synthetic: type: boolean ignored: type: boolean time: type: object properties: start: type: number end: type: number required: - start metadata: type: object propertyNames: type: string additionalProperties: {} required: - id - sessionID - messageID - type - text SubtaskPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: subtask prompt: type: string description: type: string agent: type: string model: type: object properties: providerID: type: string modelID: type: string required: - providerID - modelID spawnMode: type: string enum: - fresh - inherit command: type: string required: - id - sessionID - messageID - type - prompt - description - agent ReasoningPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: reasoning text: type: string metadata: type: object propertyNames: type: string additionalProperties: {} time: type: object properties: start: type: number end: type: number required: - start required: - id - sessionID - messageID - type - text - time FilePart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: file mime: type: string filename: type: string url: type: string source: $ref: '#/components/schemas/FilePartSource' required: - id - sessionID - messageID - type - mime - url ToolPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: tool callID: type: string tool: type: string state: $ref: '#/components/schemas/ToolState' metadata: type: object propertyNames: type: string additionalProperties: {} required: - id - sessionID - messageID - type - callID - tool - state StepStartPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: step-start snapshot: type: string required: - id - sessionID - messageID - type StepFinishPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: step-finish reason: type: string snapshot: type: string cost: type: number tokens: type: object properties: total: type: number input: type: number output: type: number reasoning: type: number cache: type: object properties: read: type: number write: type: number required: - read - write required: - input - output - reasoning - cache required: - id - sessionID - messageID - type - reason - cost - tokens SnapshotPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: snapshot snapshot: type: string required: - id - sessionID - messageID - type - snapshot PatchPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: patch hash: type: string files: type: array items: type: string required: - id - sessionID - messageID - type - hash - files AgentPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: agent name: type: string source: type: object properties: value: type: string start: type: integer minimum: -9007199254740991 maximum: 9007199254740991 end: type: integer minimum: -9007199254740991 maximum: 9007199254740991 required: - value - start - end required: - id - sessionID - messageID - type - name RetryPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: retry attempt: type: number error: $ref: '#/components/schemas/APIError' time: type: object properties: created: type: number required: - created required: - id - sessionID - messageID - type - attempt - error - time CompactionPart: type: object properties: id: type: string pattern: ^prt.* sessionID: type: string pattern: ^ses.* messageID: type: string pattern: ^msg.* type: type: string const: compaction auto: type: boolean overflow: type: boolean tail_start_id: type: string pattern: ^msg.* customInstructions: type: string required: - id - sessionID - messageID - type - auto OutputFormat: anyOf: - $ref: '#/components/schemas/OutputFormatText' - $ref: '#/components/schemas/OutputFormatJsonSchema' SnapshotFileDiff: type: object properties: file: type: string patch: type: string additions: type: number deletions: type: number status: type: string enum: - added - deleted - modified required: - file - patch - additions - deletions ProviderAuthError: type: object properties: name: type: string const: ProviderAuthError data: type: object properties: providerID: type: string message: type: string required: - providerID - message required: - name - data UnknownError: type: object properties: name: type: string const: UnknownError data: type: object properties: message: type: string required: - message required: - name - data MessageOutputLengthError: type: object properties: name: type: string const: MessageOutputLengthError data: type: object properties: {} required: - name - data MessageAbortedError: type: object properties: name: type: string const: MessageAbortedError data: type: object properties: message: type: string required: - message required: - name - data StructuredOutputError: type: object properties: name: type: string const: StructuredOutputError data: type: object properties: message: type: string retries: type: number required: - message - retries required: - name - data ContextOverflowError: type: object properties: name: type: string const: ContextOverflowError data: type: object properties: message: type: string responseBody: type: string required: - message required: - name - data APIError: type: object properties: name: type: string const: APIError data: type: object properties: message: type: string statusCode: type: number isRetryable: type: boolean responseHeaders: type: object propertyNames: type: string additionalProperties: type: string responseBody: type: string metadata: type: object propertyNames: type: string additionalProperties: type: string required: - message - isRetryable required: - name - data FilePartSource: anyOf: - $ref: '#/components/schemas/FileSource' - $ref: '#/components/schemas/SymbolSource' - $ref: '#/components/schemas/ResourceSource' ToolState: anyOf: - $ref: '#/components/schemas/ToolStatePending' - $ref: '#/components/schemas/ToolStateRunning' - $ref: '#/components/schemas/ToolStateCompleted' - $ref: '#/components/schemas/ToolStateError' OutputFormatText: type: object properties: type: type: string const: text required: - type OutputFormatJsonSchema: type: object properties: type: type: string const: json_schema schema: $ref: '#/components/schemas/JSONSchema' retryCount: default: 2 type: integer minimum: 0 maximum: 9007199254740991 required: - type - schema FileSource: type: object properties: text: $ref: '#/components/schemas/FilePartSourceText' type: type: string const: file path: type: string required: - text - type - path SymbolSource: type: object properties: text: $ref: '#/components/schemas/FilePartSourceText' type: type: string const: symbol path: type: string range: $ref: '#/components/schemas/Range' name: type: string kind: type: integer minimum: -9007199254740991 maximum: 9007199254740991 required: - text - type - path - range - name - kind ResourceSource: type: object properties: text: $ref: '#/components/schemas/FilePartSourceText' type: type: string const: resource clientName: type: string uri: type: string required: - text - type - clientName - uri ToolStatePending: type: object properties: status: type: string const: pending input: type: object propertyNames: type: string additionalProperties: {} raw: type: string required: - status - input - raw ToolStateRunning: type: object properties: status: type: string const: running input: type: object propertyNames: type: string additionalProperties: {} title: type: string metadata: type: object propertyNames: type: string additionalProperties: {} time: type: object properties: start: type: number required: - start required: - status - input - time ToolStateCompleted: type: object properties: status: type: string const: completed input: type: object propertyNames: type: string additionalProperties: {} output: type: string title: type: string metadata: type: object propertyNames: type: string additionalProperties: {} time: type: object properties: start: type: number end: type: number compacted: type: number required: - start - end attachments: type: array items: $ref: '#/components/schemas/FilePart' required: - status - input - output - title - metadata - time ToolStateError: type: object properties: status: type: string const: error input: type: object propertyNames: type: string additionalProperties: {} error: type: string metadata: type: object propertyNames: type: string additionalProperties: {} time: type: object properties: start: type: number end: type: number required: - start - end required: - status - input - error - time JSONSchema: type: object propertyNames: type: string additionalProperties: {} FilePartSourceText: type: object properties: value: type: string start: type: integer minimum: -9007199254740991 maximum: 9007199254740991 end: type: integer minimum: -9007199254740991 maximum: 9007199254740991 required: - value - start - end Range: type: object properties: start: type: object properties: line: type: number character: type: number required: - line - character end: type: object properties: line: type: number character: type: number required: - line - character required: - start - end ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.