> ## Documentation Index > Fetch the complete documentation index at: https://docs.revoengine.com/llms.txt > Use this file to discover all available pages before exploring further. # Change a Studio message reaction > Add or remove one emoji reaction as an authorized session participant and journal the touched message. ## OpenAPI ````yaml /api-reference/openapi.json post /api/v1/studio/sessions/{sessionId}/chat/messages/{messageId}/reactions openapi: 3.0.0 info: title: RevoEngine Platform API description: Official RevoEngine Platform API documentation. version: 1.7.0 contact: name: Support email: support@revoengine.com termsOfService: https://docs.revoengine.com/tos servers: - url: https://api.revoengine.com description: Production security: [] tags: - name: Accounts description: Users, service accounts, API keys, status, and platform access. externalDocs: description: Identity and access guide url: https://docs.revoengine.com/operate/identity-and-access - name: Activity description: Snapshot-backed activity and version history. externalDocs: description: Observability guide url: https://docs.revoengine.com/operate/observability - name: Agent Memory description: Administrative access to durable Agent memory. externalDocs: description: Agent memory and workspaces guide url: https://docs.revoengine.com/ai/memory-and-workspaces - name: Agent Plugins description: Agent plugin definitions, synchronization, testing, and lifecycle. externalDocs: description: Agent plugins guide url: https://docs.revoengine.com/ai/plugins - name: Agent Terminals description: Terminal pairing, owner grants, access, and command activity. externalDocs: description: Connect a terminal guide url: https://docs.revoengine.com/ai/terminals - name: Agents description: >- Agent definitions, runs, sessions, inboxes, memory, tools, workspaces, and lifecycle. externalDocs: description: Autonomous Agents guide url: https://docs.revoengine.com/ai/agents - name: Assistant description: >- Assistant threads, messages, responses, goals, reports, sharing, attachments, and control. externalDocs: description: Assistant guide url: https://docs.revoengine.com/ai/assistant - name: Automation description: >- Jobs, templates, schedules, events, webhooks, execution history, and lifecycle. externalDocs: description: Automation guide url: https://docs.revoengine.com/operate/automation - name: Browser Profiles description: >- Manage browser profile metadata, access, assignments and active sessions without exposing website authentication state. externalDocs: description: Browser profiles and collaboration guide url: https://docs.revoengine.com/ai/browser - name: Chat description: Collaborative chat threads, messages, reactions, uploads, and attachments. externalDocs: description: Team Chat guide url: https://docs.revoengine.com/operate/chat - name: Component deployments description: >- Custom Node.js runtime deployment attempts, readiness, activation, and rollback. externalDocs: description: Custom Node.js guide url: https://docs.revoengine.com/build/custom-nodejs - name: Components description: Components, elements, versions, validation, activation, and lifecycle. externalDocs: description: Components guide url: https://docs.revoengine.com/build/components - name: Config description: Instance configuration, usage, logs, and cache administration. externalDocs: description: Instance settings guide url: https://docs.revoengine.com/platform/instance-settings - name: Database Cache description: Instance Database cache values and statistics. externalDocs: description: Database Cache guide url: https://docs.revoengine.com/operate/database-cache - name: Database Views description: Database Views, previews, refreshes, exports, and controlled data actions. externalDocs: description: Database Views guide url: https://docs.revoengine.com/operate/database-views - name: Databases description: Database definitions, data, audits, exports, cloning, and lifecycle. externalDocs: description: Databases guide url: https://docs.revoengine.com/operate/databases - name: Endpoints description: >- Endpoint definitions, activation, validation, generated OpenAPI, and statistics. externalDocs: description: Endpoints guide url: https://docs.revoengine.com/operate/endpoints - name: Files description: Compatibility file listing, preview, download, and deletion operations. externalDocs: description: Files compatibility guide url: https://docs.revoengine.com/operate/files - name: Groups description: Groups, membership, avatars, and lifecycle. externalDocs: description: Groups guide url: https://docs.revoengine.com/operate/groups - name: Instance Vault description: Operations in the Instance Vault Platform API domain. externalDocs: description: Secrets and Vault guide url: https://docs.revoengine.com/operate/secrets - name: Me description: Current user profile, keys, avatar, and session information. externalDocs: description: Authentication guide url: https://docs.revoengine.com/developers/authentication - name: Native tests description: Operations in the Native tests Platform API domain. externalDocs: description: Native tests guide url: https://docs.revoengine.com/build/native-tests - name: Observability description: Authorized execution, performance, graph, and log evidence. externalDocs: description: Observability guide url: https://docs.revoengine.com/operate/observability - name: Preferences description: User and instance preference values. externalDocs: description: Platform UI guide url: https://docs.revoengine.com/platform/ui-tour - name: Role Groups description: Role groups, members, assigned roles, and lifecycle. externalDocs: description: Permissions guide url: https://docs.revoengine.com/operate/permissions - name: Roles description: Available platform roles and role details. externalDocs: description: Permissions guide url: https://docs.revoengine.com/operate/permissions - name: Search description: Cross-domain search over objects visible to the caller. externalDocs: description: Search and discovery guide url: https://docs.revoengine.com/platform/search - name: Secrets description: >- Secret definitions, revision history, explicit rotation, activation, reveal, disable, and destruction. externalDocs: description: Secrets guide url: https://docs.revoengine.com/operate/secrets - name: Share description: >- Short-lived authenticated links to supported application routes and grid state. externalDocs: description: Platform API share-link guide url: >- https://docs.revoengine.com/developers/platform-api#share-application-context - name: Storage description: >- Storage workspaces, folders, objects, upload sessions, signed access, and lifecycle. externalDocs: description: Storage guide url: https://docs.revoengine.com/operate/storage - name: Studio description: >- Manage durable Studio coding sessions, participants, shared discussion, tests, review and explicitly activated releases. Available only on enabled instances. externalDocs: description: Studio sessions guide url: https://docs.revoengine.com/build/studio-sessions externalDocs: description: Documentation url: https://docs.revoengine.com paths: /api/v1/studio/sessions/{sessionId}/chat/messages/{messageId}/reactions: post: tags: - Studio summary: Change a Studio message reaction description: >- Add or remove one emoji reaction as an authorized session participant and journal the touched message. operationId: StudioController_reactMessage parameters: - name: sessionId required: true in: path schema: type: string - name: messageId required: true in: path schema: type: string requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/StudioChatReactionDto' responses: '201': description: '' security: - bearer: [] components: schemas: StudioChatReactionDto: type: object properties: operationId: type: string format: uuid description: Caller-generated UUID idempotency key for this exact operation. studioActorId: type: string format: uuid description: >- Optional expected actor identity. The host derives the actual actor from verified execution ancestry. emoji: type: string description: >- Single emoji reaction. Text aliases and custom labels are not accepted. example: 👍 maxLength: 32 pattern: >- ^(?:(?:[\u00A9\u00AE\u203C\u2049\u2122\u2139\u2194-\u2199\u21A9-\u21AA\u231A-\u231B\u2328\u23CF\u23E9-\u23F3\u23F8-\u23FA\u24C2\u25AA-\u25AB\u25B6\u25C0\u25FB-\u25FE\u2600-\u2604\u260E\u2611\u2614-\u2615\u2618\u261D\u2620\u2622-\u2623\u2626\u262A\u262E-\u262F\u2638-\u263A\u2640\u2642\u2648-\u2653\u265F-\u2660\u2663\u2665-\u2666\u2668\u267B\u267E-\u267F\u2692-\u2697\u2699\u269B-\u269C\u26A0-\u26A1\u26A7\u26AA-\u26AB\u26B0-\u26B1\u26BD-\u26BE\u26C4-\u26C5\u26C8\u26CE-\u26CF\u26D1\u26D3-\u26D4\u26E9-\u26EA\u26F0-\u26F5\u26F7-\u26FA\u26FD\u2702\u2705\u2708-\u270D\u270F\u2712\u2714\u2716\u271D\u2721\u2728\u2733-\u2734\u2744\u2747\u274C\u274E\u2753-\u2755\u2757\u2763-\u2764\u2795-\u2797\u27A1\u27B0\u27BF\u2934-\u2935\u2B05-\u2B07\u2B1B-\u2B1C\u2B50\u2B55\u3030\u303D\u3297\u3299]|[\uD83C][\uDC04\uDC2C-\uDC2F\uDC94-\uDC9F\uDCAF-\uDCB0\uDCC0\uDCCF-\uDCD0\uDCF6-\uDCFF\uDD70-\uDD71\uDD7E-\uDD7F\uDD8E\uDD91-\uDD9A\uDDAE-\uDDE5\uDE01-\uDE0F\uDE1A\uDE2F\uDE32-\uDE3A\uDE3C-\uDE3F\uDE49-\uDE5F\uDE66-\uDF21\uDF24-\uDF93\uDF96-\uDF97\uDF99-\uDF9B\uDF9E-\uDFF0\uDFF3-\uDFF5\uDFF7-\uDFFA]|[\uD83D][\uDC00-\uDCFD\uDCFF-\uDD3D\uDD49-\uDD4E\uDD50-\uDD67\uDD6F-\uDD70\uDD73-\uDD7A\uDD87\uDD8A-\uDD8D\uDD90\uDD95-\uDD96\uDDA4-\uDDA5\uDDA8\uDDB1-\uDDB2\uDDBC\uDDC2-\uDDC4\uDDD1-\uDDD3\uDDDC-\uDDDE\uDDE1\uDDE3\uDDE8\uDDEF\uDDF3\uDDFA-\uDE4F\uDE80-\uDEC5\uDECB-\uDED2\uDED5-\uDEE5\uDEE9\uDEEB-\uDEF0\uDEF3-\uDEFF\uDFDA-\uDFFF]|[\uD83E][\uDC0C-\uDC0F\uDC48-\uDC4F\uDC5A-\uDC5F\uDC88-\uDC8F\uDCAE-\uDCAF\uDCBC-\uDCBF\uDCC2-\uDCCF\uDCD9-\uDCFF\uDD0C-\uDD3A\uDD3C-\uDD45\uDD47-\uDDFF\uDE58-\uDE5F\uDE6E-\uDEFF]|[\uD83F][\uDC00-\uDFFD])(?:\uFE0F|\uD83C[\uDFFB-\uDFFF])?(?:\u200D(?:[\u00A9\u00AE\u203C\u2049\u2122\u2139\u2194-\u2199\u21A9-\u21AA\u231A-\u231B\u2328\u23CF\u23E9-\u23F3\u23F8-\u23FA\u24C2\u25AA-\u25AB\u25B6\u25C0\u25FB-\u25FE\u2600-\u2604\u260E\u2611\u2614-\u2615\u2618\u261D\u2620\u2622-\u2623\u2626\u262A\u262E-\u262F\u2638-\u263A\u2640\u2642\u2648-\u2653\u265F-\u2660\u2663\u2665-\u2666\u2668\u267B\u267E-\u267F\u2692-\u2697\u2699\u269B-\u269C\u26A0-\u26A1\u26A7\u26AA-\u26AB\u26B0-\u26B1\u26BD-\u26BE\u26C4-\u26C5\u26C8\u26CE-\u26CF\u26D1\u26D3-\u26D4\u26E9-\u26EA\u26F0-\u26F5\u26F7-\u26FA\u26FD\u2702\u2705\u2708-\u270D\u270F\u2712\u2714\u2716\u271D\u2721\u2728\u2733-\u2734\u2744\u2747\u274C\u274E\u2753-\u2755\u2757\u2763-\u2764\u2795-\u2797\u27A1\u27B0\u27BF\u2934-\u2935\u2B05-\u2B07\u2B1B-\u2B1C\u2B50\u2B55\u3030\u303D\u3297\u3299]|[\uD83C][\uDC04\uDC2C-\uDC2F\uDC94-\uDC9F\uDCAF-\uDCB0\uDCC0\uDCCF-\uDCD0\uDCF6-\uDCFF\uDD70-\uDD71\uDD7E-\uDD7F\uDD8E\uDD91-\uDD9A\uDDAE-\uDDE5\uDE01-\uDE0F\uDE1A\uDE2F\uDE32-\uDE3A\uDE3C-\uDE3F\uDE49-\uDE5F\uDE66-\uDF21\uDF24-\uDF93\uDF96-\uDF97\uDF99-\uDF9B\uDF9E-\uDFF0\uDFF3-\uDFF5\uDFF7-\uDFFA]|[\uD83D][\uDC00-\uDCFD\uDCFF-\uDD3D\uDD49-\uDD4E\uDD50-\uDD67\uDD6F-\uDD70\uDD73-\uDD7A\uDD87\uDD8A-\uDD8D\uDD90\uDD95-\uDD96\uDDA4-\uDDA5\uDDA8\uDDB1-\uDDB2\uDDBC\uDDC2-\uDDC4\uDDD1-\uDDD3\uDDDC-\uDDDE\uDDE1\uDDE3\uDDE8\uDDEF\uDDF3\uDDFA-\uDE4F\uDE80-\uDEC5\uDECB-\uDED2\uDED5-\uDEE5\uDEE9\uDEEB-\uDEF0\uDEF3-\uDEFF\uDFDA-\uDFFF]|[\uD83E][\uDC0C-\uDC0F\uDC48-\uDC4F\uDC5A-\uDC5F\uDC88-\uDC8F\uDCAE-\uDCAF\uDCBC-\uDCBF\uDCC2-\uDCCF\uDCD9-\uDCFF\uDD0C-\uDD3A\uDD3C-\uDD45\uDD47-\uDDFF\uDE58-\uDE5F\uDE6E-\uDEFF]|[\uD83F][\uDC00-\uDFFD])(?:\uFE0F|\uD83C[\uDFFB-\uDFFF])?)*|(?:\uD83C[\uDDE6-\uDDFF]){2})$ remove: type: boolean description: Remove this reaction instead of adding it. required: - operationId - emoji securitySchemes: bearer: scheme: bearer bearerFormat: JWT description: Bearer JWT token or API Key (sk-*). type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.