# Reassign API

> Reassign is a 24-hour day planner. Developers can read and change a day plan with the REST API (base URL https://reassign.app/api/v1) or connect an AI assistant to the MCP server (https://reassign.app/api/mcp). The REST API takes a personal access token or an OAuth 2.0 token as `Authorization: Bearer <token>`; the MCP server uses OAuth 2.0. Support: developers@reassign.dev.

Each page below is also available as HTML at the same path without `.md`. All pages in one file: https://reassign.dev/llms-full.txt. The OpenAPI 3.1 spec of the public API: https://reassign.dev/openapi.json

## Guides

- [Reassign API](https://reassign.dev/index.md): Build on Reassign, the 24-hour day planner. Read and change a day plan with the REST API, or connect an AI assistant through the MCP server.
- [Quickstart](https://reassign.dev/quickstart.md): Create a personal access token, make your first request to the Reassign REST API, read a day, and add an event.
- [Authentication](https://reassign.dev/authentication.md): Authenticate your requests to the Reassign REST API with a personal access token or with OAuth 2.0.
- [Connect an AI assistant](https://reassign.dev/mcp.md): Connect an AI assistant to the Reassign MCP server. The assistant can then read and change your day plan.
- [Core concepts](https://reassign.dev/concepts.md): The model behind the Reassign API: the day plan, local datetimes and spans, names and formats, validation, recurring events, categories, projects and priority, checklists, focus intervals, change polls, the Inbox, trackers, reviews, calendars, undo, and scopes.
- [Errors](https://reassign.dev/errors.md): The error format of the Reassign REST API, the error codes, rejected batches, the rate limits, and how to handle errors.

## API reference

- [Account](https://reassign.dev/reference/account.md): Read the identity, the plan, and the scopes of the token that calls the Reassign REST API.
- [Events](https://reassign.dev/reference/events.md): Poll, read, search, create, change, and delete events on the Reassign 24-hour planner with the REST API.
- [Scheduling](https://reassign.dev/reference/scheduling.md): Read days, find free time, book work into it, and undo changes with the Reassign REST API.
- [Categories](https://reassign.dev/reference/categories.md): Read, create, update, and delete the areas, activity types, and projects of a Reassign account.
- [Backlog](https://reassign.dev/reference/backlog.md): Read and change the Inbox of a Reassign account: capture blocks, schedule them on a day, and move events back.
- [Moments & trackers](https://reassign.dev/reference/moments-and-trackers.md): Define trackers, then log, read, edit, and delete moments with the Reassign REST API.
- [Day reviews](https://reassign.dev/reference/day-reviews.md): Record how a past day went, then confirm or discard the review of that day with the Reassign REST API.
- [Energy & weather](https://reassign.dev/reference/energy-and-weather.md): Read the forecast energy curve and the weather report for a day. Both endpoints return a short text report.
- [Calendars](https://reassign.dev/reference/calendars.md): List the calendars and task lists from the connected sources of the user. Use the ids to sync events.
- [Quick command (AI)](https://reassign.dev/reference/command.md): Send one line or a braindump of free text. An AI model turns it into events, Inbox blocks, and logged moments, and applies them.

## Optional

- [Changelog](https://reassign.dev/changelog.md): Changes to the Reassign API and to its documentation.