diff --git a/README.md b/README.md
index 198b174a..ff2c786d 100644
--- a/README.md
+++ b/README.md
@@ -127,6 +127,41 @@ http://localhost:9876/v15.0/5549988290955/messages \
 }'
 ```
 
+To react to a message
+
+```sh
+curl -i -X POST \
+http://localhost:9876/v15.0/5549988290955/messages \
+-H 'Content-Type: application/json' \
+-H 'Authorization: 1' \
+-d '{
+  "messaging_product": "whatsapp",
+  "to": "5549988290955",
+  "type": "reaction",
+  "reaction": {
+    "message_id": "MESSAGE_ID",
+    "emoji": "👍"
+  }
+}'
+```
+
+To send a sticker (PNG/JPG/GIF are auto-converted to WEBP)
+
+```sh
+curl -i -X POST \
+http://localhost:9876/v15.0/5549988290955/messages \
+-H 'Content-Type: application/json' \
+-H 'Authorization: 1' \
+-d '{
+  "messaging_product": "whatsapp",
+  "to": "5549988290955",
+  "type": "sticker",
+  "sticker": {
+    "link": "https://example.com/sticker.png"
+  }
+}'
+```
+
 ## Media
 
 To test media
diff --git a/__tests__/services/reaction_helper.ts b/__tests__/services/reaction_helper.ts
new file mode 100644
index 00000000..fa3fd079
--- /dev/null
+++ b/__tests__/services/reaction_helper.ts
@@ -0,0 +1,80 @@
+import { resolveReactionPayload } from '../../src/services/reaction_helper'
+import { SendError } from '../../src/services/send_error'
+import { toBaileysMessageContent } from '../../src/services/transformer'
+
+describe('resolveReactionPayload', () => {
+  test('resolves reaction key and target', async () => {
+    const loadKey = jest.fn(async (id: string) => {
+      if (id === 'UNO_ID') {
+        return {
+          id: 'BAILEYS_ID',
+          remoteJid: '554988189915@s.whatsapp.net',
+          fromMe: true,
+        }
+      }
+      return undefined
+    })
+    const loadUnoId = jest.fn(async (id: string) => (id === 'MSG_ID' ? 'UNO_ID' : undefined))
+    const loadMessage = jest.fn(async () => ({ key: { id: 'BAILEYS_ID', remoteJid: '554988189915@s.whatsapp.net', fromMe: true } }))
+    const dataStore = { loadKey, loadUnoId, loadMessage }
+    const payload = {
+      type: 'reaction',
+      reaction: { message_id: 'MSG_ID', emoji: '👍' },
+    }
+    const result = await resolveReactionPayload(payload, dataStore)
+    expect(result.emoji).toEqual('👍')
+    expect(result.targetTo).toEqual('554988189915@s.whatsapp.net')
+    expect(result.reactionKey).toMatchObject({ id: 'BAILEYS_ID', remoteJid: '554988189915@s.whatsapp.net' })
+  })
+
+  test('throws on missing message_id', async () => {
+    const dataStore = {}
+    await expect(resolveReactionPayload({ type: 'reaction', reaction: { emoji: 'ok' } }, dataStore)).rejects.toBeInstanceOf(SendError)
+  })
+
+  test('cloud api reaction payload to baileys content', async () => {
+    const dataStore = {
+      loadKey: jest.fn(async (id: string) => {
+        if (id === '3EB0778F74E14FF7B1FCA4') {
+          return {
+            id: 'BAILEYS_ID',
+            remoteJid: '556696269251@s.whatsapp.net',
+            fromMe: true,
+          }
+        }
+        return undefined
+      }),
+      loadUnoId: jest.fn(async () => undefined),
+      loadMessage: jest.fn(async () => ({ key: { id: 'BAILEYS_ID', remoteJid: '556696269251@s.whatsapp.net', fromMe: true } })),
+    }
+    const cloudInput = {
+      messaging_product: 'whatsapp',
+      to: '556696269251',
+      type: 'reaction',
+      reaction: {
+        message_id: '3EB0778F74E14FF7B1FCA4',
+        emoji: '👍',
+      },
+    }
+    const resolved = await resolveReactionPayload(cloudInput, dataStore)
+    const resolvedPayload = {
+      ...cloudInput,
+      reaction: {
+        ...(cloudInput as any).reaction,
+        emoji: resolved.emoji,
+        key: resolved.reactionKey,
+      },
+    }
+    const result = toBaileysMessageContent(resolvedPayload)
+    expect(result).toEqual({
+      react: {
+        text: '👍',
+        key: {
+          id: 'BAILEYS_ID',
+          remoteJid: '556696269251@s.whatsapp.net',
+          fromMe: true,
+        },
+      },
+    })
+  })
+})
diff --git a/__tests__/services/transformer.ts b/__tests__/services/transformer.ts
index 06dee71b..80f737a6 100644
--- a/__tests__/services/transformer.ts
+++ b/__tests__/services/transformer.ts
@@ -22,6 +22,7 @@ import {
   extractFromPhone,
   extractTypeMessage,
 } from '../../src/services/transformer'
+import { resolveReactionPayload } from '../../src/services/reaction_helper'
 const key = { remoteJid: 'XXXX@s.whatsapp.net', id: 'abc' }
 
 const documentMessage: proto.Message.IDocumentMessage = {
@@ -1652,6 +1653,143 @@ describe('service transformer', () => {
     expect(result).toEqual(output)
   })
 
+  const buildReactionDataStore = () => ({
+    loadKey: jest.fn(async (id: string) => {
+      if (id === 'REACTION_MESSAGE_ID') {
+        return {
+          id: 'REACTION_KEY_ID',
+          remoteJid: '554988189915@s.whatsapp.net',
+          fromMe: true,
+        }
+      }
+      return undefined
+    }),
+    loadUnoId: jest.fn(async () => undefined),
+    loadMessage: jest.fn(async () => ({ key: { id: 'REACTION_KEY_ID', remoteJid: '554988189915@s.whatsapp.net', fromMe: true } })),
+  })
+
+  test('toBaileysMessageContent reaction (cloud input)', async () => {
+    const cloudInput = {
+      messaging_product: 'whatsapp',
+      to: '554988189915',
+      type: 'reaction',
+      reaction: {
+        message_id: 'REACTION_MESSAGE_ID',
+        emoji: 'ok',
+      },
+    }
+    const resolved = await resolveReactionPayload(cloudInput, buildReactionDataStore())
+    const resolvedPayload = {
+      ...cloudInput,
+      reaction: {
+        ...(cloudInput as any).reaction,
+        emoji: resolved.emoji,
+        key: resolved.reactionKey,
+      },
+    }
+    const result = toBaileysMessageContent(resolvedPayload)
+    expect(result).toEqual({
+      react: {
+        text: 'ok',
+        key: {
+          remoteJid: '554988189915@s.whatsapp.net',
+          fromMe: true,
+          id: 'REACTION_KEY_ID',
+        },
+      },
+    })
+  })
+
+  test('toBaileysMessageContent reaction without emoji (cloud input)', async () => {
+    const cloudInput = {
+      messaging_product: 'whatsapp',
+      to: '554988189915',
+      type: 'reaction',
+      reaction: {
+        message_id: 'REACTION_MESSAGE_ID',
+      },
+    }
+    const resolved = await resolveReactionPayload(cloudInput, buildReactionDataStore())
+    const resolvedPayload = {
+      ...cloudInput,
+      reaction: {
+        ...(cloudInput as any).reaction,
+        emoji: resolved.emoji,
+        key: resolved.reactionKey,
+      },
+    }
+    const result = toBaileysMessageContent(resolvedPayload)
+    expect(result).toEqual({
+      react: {
+        text: '',
+        key: {
+          remoteJid: '554988189915@s.whatsapp.net',
+          fromMe: true,
+          id: 'REACTION_KEY_ID',
+        },
+      },
+    })
+  })
+
+  test('toBaileysMessageContent reaction with empty emoji (cloud input)', async () => {
+    const cloudInput = {
+      messaging_product: 'whatsapp',
+      to: '554988189915',
+      type: 'reaction',
+      reaction: {
+        message_id: 'REACTION_MESSAGE_ID',
+        emoji: '',
+      },
+    }
+    const resolved = await resolveReactionPayload(cloudInput, buildReactionDataStore())
+    const resolvedPayload = {
+      ...cloudInput,
+      reaction: {
+        ...(cloudInput as any).reaction,
+        emoji: resolved.emoji,
+        key: resolved.reactionKey,
+      },
+    }
+    const result = toBaileysMessageContent(resolvedPayload)
+    expect(result).toEqual({
+      react: {
+        text: '',
+        key: {
+          remoteJid: '554988189915@s.whatsapp.net',
+          fromMe: true,
+          id: 'REACTION_KEY_ID',
+        },
+      },
+    })
+  })
+
+  test('toBaileysMessageContent reaction without key', async () => {
+    const input = {
+      type: 'reaction',
+      reaction: {
+        emoji: 'ok',
+      },
+    }
+    expect(() => toBaileysMessageContent(input)).toThrow('invalid_reaction_payload: missing key')
+  })
+
+  test('toBaileysMessageContent sticker', async () => {
+    const input = {
+      type: 'sticker',
+      sticker: {
+        link: 'https://example.com/sticker.png',
+      },
+    }
+    const output = {
+      mimetype: 'image/png',
+      sticker: {
+        url: 'https://example.com/sticker.png',
+      },
+    }
+    const result = toBaileysMessageContent(input)
+    expect(result).toEqual(output)
+  })
+
   test('fromBaileysMessageContent participant outside key', async () => {
     const phoneNumer = '5549998093075'
     const remotePhoneNumber = '11115551212'
@@ -2467,4 +2605,4 @@ describe('service transformer', () => {
 //       }
 //     }
 //   }
-// }
\ No newline at end of file
+// }
diff --git a/src/services/client_baileys.ts b/src/services/client_baileys.ts
index 8c2f6caf..ec4cea42 100644
--- a/src/services/client_baileys.ts
+++ b/src/services/client_baileys.ts
@@ -37,6 +37,8 @@ import { t } from '../i18n'
 import { ClientForward } from './client_forward'
 import { SendError } from './send_error'
 import audioConverter from '../utils/audio_converter'
+import { convertToWebpSticker } from '../utils/sticker_convert'
+import { resolveReactionPayload } from './reaction_helper'
 
 const attempts = 3
 
@@ -239,6 +241,40 @@ export class ClientBaileys implements Client {
     await this.connect(time)
   }
 
+  private async maybeConvertStickerToWebp(content: any, payload: any) {
+    try {
+      const stickerPayload: any = payload?.sticker || {}
+      const stickerLink = stickerPayload?.link || (content as any)?.sticker?.url
+      const cleanLink = `${stickerLink || ''}`.split('?')[0].split('#')[0]
+      const stickerMimeRaw = `${stickerPayload?.mime_type || stickerPayload?.mimetype || (content as any)?.mimetype || ''}`.toLowerCase()
+      const isWebp = stickerMimeRaw.includes('webp') || cleanLink.toLowerCase().endsWith('.webp')
+      if (stickerLink && !isWebp && typeof (content as any)?.sticker === 'object' && (content as any)?.sticker?.url) {
+        const resp = await fetch(stickerLink, { signal: AbortSignal.timeout(FETCH_TIMEOUT_MS), method: 'GET' })
+        if (!resp?.ok) {
+          throw new Error(`sticker_download_failed: ${resp?.status || 0}`)
+        }
+        const MAX_STICKER_BYTES = 8 * 1024 * 1024
+        const contentLength = Number(resp.headers.get('content-length') || 0)
+        if (contentLength && contentLength > MAX_STICKER_BYTES) {
+          throw new Error(`sticker_too_large: ${contentLength}`)
+        }
+        const contentType = `${resp.headers.get('content-type') || ''}`.toLowerCase()
+        const isAnimated = contentType.includes('gif') || cleanLink.toLowerCase().endsWith('.gif')
+        const arrayBuffer = await resp.arrayBuffer()
+        if (arrayBuffer.byteLength > MAX_STICKER_BYTES) {
+          throw new Error(`sticker_too_large: ${arrayBuffer.byteLength}`)
+        }
+        const buf = Buffer.from(arrayBuffer)
+        const webp = await convertToWebpSticker(buf, { animated: isAnimated })
+        ;(content as any).sticker = webp
+        ;(content as any).mimetype = 'image/webp'
+        logger.debug('Sticker converted to webp for %s', stickerLink)
+      }
+    } catch (err) {
+      logger.warn(err, 'Ignore error converting sticker to webp sending original')
+    }
+  }
+
   private delayBeforeSecondMessage: Delay = async (phone, to) => {
     const time = 2000
     logger.debug(`Sleep for ${time} before second message ${phone} => ${to}`)
@@ -413,7 +449,9 @@ export class ClientBaileys implements Client {
 
   // eslint-disable-next-line @typescript-eslint/no-explicit-any
   async send(payload: any, options: any = {}) {
-    const { status, type, to } = payload
+    const { status, type } = payload
+    let { to } = payload
+    let safeTo = to || this.phone
     try {
       if (status) {
         if (['sent', 'delivered', 'failed', 'progress', 'read', 'deleted'].includes(status)) {
@@ -465,9 +503,27 @@ export class ClientBaileys implements Client {
           throw new Error(`Unknow message status ${status}`)
         }
       } else if (type) {
-        if (['text', 'image', 'audio', 'sticker', 'document', 'video', 'template', 'interactive', 'contacts'].includes(type)) {
+        if (['text', 'image', 'audio', 'sticker', 'document', 'video', 'template', 'interactive', 'contacts', 'reaction'].includes(type)) {
           let content
-          if ('template' === type) {
+          let targetTo = to
+          const extraSendOptions: any = {}
+          if ('reaction' === type) {
+            const resolved = await resolveReactionPayload(payload, this.store?.dataStore)
+            const resolvedPayload = {
+              ...payload,
+              reaction: {
+                ...(payload?.reaction || {}),
+                emoji: resolved.emoji,
+                key: resolved.reactionKey,
+              },
+            }
+            content = toBaileysMessageContent(resolvedPayload, this.config.customMessageCharactersFunction)
+            targetTo = resolved.targetTo
+            to = targetTo
+            safeTo = targetTo
+            extraSendOptions.forceRemoteJid = resolved.targetTo
+            extraSendOptions.skipBrSendOrder = true
+          } else if ('template' === type) {
             const template = new Template(this.getConfig)
             content = await template.bind(this.phone, payload.template.name, payload.template.components)
           } else {
@@ -481,6 +537,9 @@ export class ClientBaileys implements Client {
               }
             }
             content = toBaileysMessageContent(payload, this.config.customMessageCharactersFunction)
+            if (type === 'sticker') {
+              await this.maybeConvertStickerToWebp(content, payload)
+            }
           }
           let quoted: WAMessage | undefined = undefined
           let disappearingMessagesInChat: boolean | number = false
@@ -490,7 +549,7 @@ export class ClientBaileys implements Client {
             const key = await this.store?.dataStore?.loadKey(messageId)
             logger.debug('Quoted message key %s!', key?.id)
             if (key?.id) {
-              const remoteJid = phoneNumberToJid(to)
+              const remoteJid = phoneNumberToJid(targetTo)
               quoted = await this.store?.dataStore.loadMessage(remoteJid, key?.id)
               if (!quoted) {
                 const unoId = await this.store?.dataStore?.loadUnoId(key?.id)
@@ -527,12 +586,12 @@ export class ClientBaileys implements Client {
           // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
           const sockDelays = delays.get(this.phone) || (delays.set(this.phone, new Map<string, Delay>()) && delays.get(this.phone)!)
           // eslint-disable-next-line @typescript-eslint/no-unused-vars
-          const toDelay = sockDelays.get(to) || (async (_phone: string, to) => sockDelays.set(to, this.delayBeforeSecondMessage))
-          await toDelay(this.phone, to)
+          const toDelay = sockDelays.get(targetTo) || (async (_phone: string, to) => sockDelays.set(to, this.delayBeforeSecondMessage))
+          await toDelay(this.phone, targetTo)
           let response
           if (content?.listMessage) {
             response = await this.sendMessage(
-              to,
+              targetTo,
               {
                 forward: {
                   key: {
@@ -548,14 +607,16 @@ export class ClientBaileys implements Client {
                 composing: this.config.composingMessage,
                 quoted,
                 disappearingMessagesInChat,
+                ...extraSendOptions,
                 ...options,
               },
             )
           } else {
-            response = await this.sendMessage(to, content, {
+            response = await this.sendMessage(targetTo, content, {
               composing: this.config.composingMessage,
               quoted,
               disappearingMessagesInChat,
+              ...extraSendOptions,
               ...options,
             })
           }
@@ -611,7 +672,7 @@ export class ClientBaileys implements Client {
           messaging_product: 'whatsapp',
           contacts: [
             {
-              wa_id: jidToPhoneNumber(to, ''),
+              wa_id: jidToPhoneNumber(safeTo, ''),
             },
           ],
           messages: [
@@ -636,7 +697,7 @@ export class ClientBaileys implements Client {
                     statuses: [
                       {
                         id,
-                        recipient_id: jidToPhoneNumber(to || this.phone, ''),
+                        recipient_id: jidToPhoneNumber(safeTo, ''),
                         status: 'failed',
                         timestamp: Math.floor(Date.now() / 1000),
                         errors: [
diff --git a/src/services/reaction_helper.ts b/src/services/reaction_helper.ts
new file mode 100644
index 00000000..fb5ca0c1
--- /dev/null
+++ b/src/services/reaction_helper.ts
@@ -0,0 +1,56 @@
+import { SendError } from './send_error'
+import logger from './logger'
+
+export type ReactionResolveResult = {
+  emoji: string
+  reactionKey: any
+  targetTo: string
+  messageId: string
+}
+
+export const resolveReactionPayload = async (payload: any, dataStore: any): Promise<ReactionResolveResult> => {
+  const reaction = payload?.reaction || {}
+  const messageId =
+    reaction?.message_id ||
+    reaction?.messageId ||
+    payload?.message_id ||
+    payload?.context?.message_id ||
+    payload?.context?.id
+  if (!messageId) {
+    throw new SendError(400, 'invalid_reaction_payload: missing message_id')
+  }
+  let key = await dataStore?.loadKey(messageId)
+  if (!key) {
+    const unoId = await dataStore?.loadUnoId(messageId)
+    if (unoId) {
+      key = await dataStore?.loadKey(unoId)
+    }
+  }
+  if (!key || !key.id || !key.remoteJid) {
+    throw new SendError(404, `reaction_message_not_found: ${messageId}`)
+  }
+  const emojiRaw = typeof reaction?.emoji !== 'undefined'
+    ? reaction.emoji
+    : (typeof reaction?.text !== 'undefined' ? reaction.text : reaction?.value)
+  const emoji = `${emojiRaw ?? ''}`
+  let reactionKey = key
+  try {
+    const original = await dataStore?.loadMessage?.(reactionKey.remoteJid, reactionKey.id)
+    if (original?.key) {
+      reactionKey = { ...original.key, id: reactionKey.id }
+      if (typeof reactionKey.participant === 'string' && reactionKey.participant.trim() === '') {
+        delete (reactionKey as any).participant
+      }
+    }
+  } catch {}
+  try {
+    logger.info(
+      'REACTION send: msgId=%s key.id=%s key.remoteJid=%s key.participant=%s',
+      messageId,
+      reactionKey?.id || '<none>',
+      reactionKey?.remoteJid || '<none>',
+      (reactionKey as any)?.participant || '<none>',
+    )
+  } catch {}
+  return { emoji, reactionKey, targetTo: reactionKey.remoteJid, messageId }
+}
diff --git a/src/services/transformer.ts b/src/services/transformer.ts
index 4b0a22ec..25980602 100644
--- a/src/services/transformer.ts
+++ b/src/services/transformer.ts
@@ -464,6 +464,7 @@ export const toBaileysMessageContent = (payload: any, customMessageCharactersFun
     case 'audio':
     case 'document':
     case 'video':
+    case 'sticker':
       const link = payload[type].link
       if (link) {
         let mimetype: string = getMimetype(payload)
@@ -482,6 +483,7 @@ export const toBaileysMessageContent = (payload: any, customMessageCharactersFun
         response[type] = { url: link }
         break
       }
+      throw new Error(`invalid_media_payload: missing link for ${type}`)
 
     case 'contacts':
       const contact = payload[type][0]
@@ -502,6 +504,20 @@ export const toBaileysMessageContent = (payload: any, customMessageCharactersFun
     case 'template':
       throw new BindTemplateError()
 
+    case 'reaction': {
+      const reaction = payload?.reaction || {}
+      const key = reaction?.key
+      if (!key) {
+        throw new Error('invalid_reaction_payload: missing key')
+      }
+      const emojiRaw = typeof reaction?.emoji !== 'undefined'
+        ? reaction.emoji
+        : (typeof reaction?.text !== 'undefined' ? reaction.text : reaction?.value)
+      const emoji = `${emojiRaw ?? ''}`
+      response.react = { text: emoji, key }
+      break
+    }
+
     default:
       throw new Error(`Unknow message type ${type}`)
   }
diff --git a/src/utils/sticker_convert.ts b/src/utils/sticker_convert.ts
new file mode 100644
index 00000000..7dd2a4a8
--- /dev/null
+++ b/src/utils/sticker_convert.ts
@@ -0,0 +1,13 @@
+import sharp from 'sharp'
+
+type StickerConvertOptions = {
+  animated?: boolean
+}
+
+export const convertToWebpSticker = async (input: Buffer, opts: StickerConvertOptions = {}) => {
+  const image = sharp(input, { animated: !!opts.animated })
+  return image
+    .resize(512, 512, { fit: 'inside', withoutEnlargement: true })
+    .webp({ lossless: !opts.animated, quality: 80, effort: 4 })
+    .toBuffer()
+}