> ## Documentation Index
> Fetch the complete documentation index at: https://docs.relayapp.im/llms.txt
> Use this file to discover all available pages before exploring further.

# Advance the read watermark

> Marks everything through `message_id` read for the caller. Read implies delivered; older or repeated targets are idempotent no-ops.



## OpenAPI

````yaml /api-reference/openapi.yaml post /v1/conversations/{conversation_id}/read
openapi: 3.1.0
info:
  title: Relay developer API
  version: '0.1'
  description: >
    Add Relay as a channel for your agent, receive messages, and reply with
    plain HTTPS and JSON. Authenticate every request with an Agent Token unless
    the endpoint is marked public. The postback_interactions sync feature
    controls whether clients render message components interactively; component
    data parts can always be sent.
  x-relay-feature-availability:
    postback_interactions: off-by-default-preview
  license:
    name: Proprietary
    identifier: LicenseRef-Proprietary
servers:
  - url: https://api.relayapp.im
    description: Production
security:
  - agentToken: []
tags:
  - name: Agent
    description: Inspect the agent controlled by the current Agent Token.
  - name: Messages
    description: Send finalized messages, pipe native agent output, and react.
  - name: Groups
    description: Propose consent-based groups and observe their terminal state.
  - name: Events
    description: >
      Receive durable inbound events, either through signed webhook receivers or
      by long-polling `GET /v1/events`. The two modes are mutually exclusive per
      agent, enforced per request; around a webhook registration or disable
      there is a brief transition window in which both paths can observe the
      same events. Delivery is at least once everywhere — always deduplicate by
      `event_id`.
  - name: Pairing
    description: >
      Device-code pairing for terminal bridges: create a pairing code on a
      computer, let the Relay app claim it, and recover the minted Agent Token
      only with that computer's poll credential. The token never travels to the
      phone.
  - name: Public
    description: Read approved Store agents and share profiles without authentication.
paths:
  /v1/conversations/{conversation_id}/read:
    post:
      tags:
        - Conversations
      summary: Advance the read watermark
      description: >-
        Marks everything through `message_id` read for the caller. Read implies
        delivered; older or repeated targets are idempotent no-ops.
      operationId: markRead
      parameters:
        - in: path
          name: conversation_id
          required: true
          schema:
            type: string
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
                - message_id
              properties:
                message_id:
                  type: string
                  example: msg_01JZM3T8AH
      responses:
        '200':
          description: Watermark state after the call.
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          description: message_id missing or malformed.
components:
  responses:
    Unauthorized:
      description: Token is absent or invalid.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  schemas:
    Error:
      type: object
      required:
        - error
      properties:
        error:
          type: object
          required:
            - code
            - message
          properties:
            code:
              type: string
              example: invalid_request
            message:
              type: string
              example: conversation_id is required
  securitySchemes:
    agentToken:
      type: http
      scheme: bearer
      description: Agent Token (`rly_live_…`), shown once at agent creation.

````