> ## Documentation Index > Fetch the complete documentation index at: https://docs.hyperprop.com/llms.txt > Use this file to discover all available pages before exploring further. # Save a journal note > Creates or replaces the note for one trading day (`scope: "day"`, `ref` = the day) or one trade (`scope: "trade"`, `ref` = `:`). Text up to 5000 characters; up to 10 tags of up to 24 characters (trimmed, a leading # removed, duplicates ignored). Saving an empty note with no tags deletes it and returns `note: null`. ## OpenAPI ````yaml /api-reference/openapi.json put /v1/user/journal/notes openapi: 3.0.0 info: title: Hyperprop Platform API version: 1.0.0 description: >- REST API for the Hyperprop Trading Platform — provision evaluation and funded trading accounts, manage traders and plans, react to account lifecycle events via signed webhooks, and reconcile billing. Built for prop firms integrating from their own backend. Authentication, quick start, error handling, idempotency, pagination, custom metadata, webhooks, and the MCP connector are documented at https://docs.hyperprop.com. x-logo: url: https://app.hyperprop.com/logo-icon.svg altText: Hyperprop href: https://hyperprop.com servers: - url: https://api.hyperprop.com/platform description: Production security: [] tags: - name: Authentication description: >- User authentication - signup, signin, signout, password reset, email verification, OAuth, and MFA - name: User description: >- User account management - profile, notifications, agreements, dismissals, and audit logs. Requires Bearer token. - name: Organization description: >- Organization management - profile, team, trading accounts, plans, and rules. Supports **dual authentication**: Bearer JWT token (dashboard users) OR X-API-Key (programmatic access). - name: Market Data description: CME futures contracts and market data. Requires Bearer token. - name: Indicator Builder description: >- AI-assisted authoring of custom Hyperprop Script indicators for the web terminal. Requires Bearer token. - name: System description: System endpoints - health checks and connectivity paths: /v1/user/journal/notes: put: tags: - User summary: Save a journal note description: >- Creates or replaces the note for one trading day (`scope: "day"`, `ref` = the day) or one trade (`scope: "trade"`, `ref` = `:`). Text up to 5000 characters; up to 10 tags of up to 24 characters (trimmed, a leading # removed, duplicates ignored). Saving an empty note with no tags deletes it and returns `note: null`. operationId: putV1UserJournalNotes requestBody: content: application/json: schema: $ref: '#/components/schemas/Model852' responses: '200': description: Note saved (or deleted when empty) content: '*/*': schema: $ref: '#/components/schemas/Model856' '400': description: Invalid request data content: '*/*': schema: $ref: '#/components/schemas/Model212' '401': description: Authentication required content: '*/*': schema: $ref: '#/components/schemas/Model9' '500': description: An unexpected error occurred content: '*/*': schema: $ref: '#/components/schemas/Model5' components: schemas: Model852: type: object properties: scope: $ref: '#/components/schemas/Model850' ref: type: string maxLength: 200 tradingDay: type: string pattern: ^\d{4}-\d{2}-\d{2}$ note: type: string default: '' maxLength: 5000 tags: $ref: '#/components/schemas/Model851' required: - scope - ref - tradingDay Model856: type: object properties: success: type: boolean example: true data: $ref: '#/components/schemas/Model855' Model212: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 400 error: type: string example: Bad Request message: type: string example: Invalid request data code: type: string description: Machine-readable error code — switch on this, not on message text example: BAD_REQUEST Model9: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 401 error: type: string example: Unauthorized message: type: string example: Authentication required code: type: string description: Machine-readable error code — switch on this, not on message text example: UNAUTHORIZED Model5: type: object properties: success: type: boolean description: Always false on errors example: false statusCode: type: number example: 500 error: type: string example: Internal Server Error message: type: string example: An unexpected error occurred code: type: string description: Machine-readable error code — switch on this, not on message text example: INTERNAL_ERROR Model850: type: string enum: - day - trade Model851: type: array maxItems: 50 items: type: string maxLength: 100 Model855: type: object properties: note: $ref: '#/components/schemas/note' note: type: object properties: scope: $ref: '#/components/schemas/Model853' ref: type: string description: >- The trading day (`YYYY-MM-DD`) for a day note; `:` for a trade note example: >- 7c1e0a4e-1b2c-4d5e-8f90-1234567890ab:0f9e8d7c-6b5a-4938-8271-abcdefabcdef tradingDay: type: string description: Trading day the note belongs to example: '2026-09-24' note: type: string example: Waited for the pullback — good entry, exited too early. tags: $ref: '#/components/schemas/Model854' updatedAt: type: string example: '2026-09-24T19:42:10.000Z' x-format: isoDate: true Model853: type: string example: trade enum: - day - trade Model854: type: array example: - A+ setup - Early exit items: type: string ```` ## Related topics - [List your journal notes](/platform-api/user/list-your-journal-notes.md) - [Changelog](/changelog.md) - [Save one UI preference](/platform-api/user/save-one-ui-preference.md) - [Hyperprop Script: build indicators (agent recipe)](/guides/hyperprop-script.md) - [Revoke (soft delete) a PnL card](/platform-api/pnl-cards/revoke-soft-delete-a-pnl-card.md)