diff --git a/apps/backend/package.json b/apps/backend/package.json
index 60421939..de2bcccc 100644
--- a/apps/backend/package.json
+++ b/apps/backend/package.json
@@ -17,6 +17,7 @@
     "express": "^4.18.2",
     "morgan": "^1.10.0",
     "prisma": "^5.4.2",
+    "random-animal-name": "^0.1.1",
     "uuid": "^9.0.1"
   },
   "devDependencies": {
diff --git a/apps/backend/prisma/migrations/20231012082544_external_id_optional/migration.sql b/apps/backend/prisma/migrations/20231012082544_external_id_optional/migration.sql
new file mode 100644
index 00000000..98890914
--- /dev/null
+++ b/apps/backend/prisma/migrations/20231012082544_external_id_optional/migration.sql
@@ -0,0 +1,5 @@
+-- DropIndex
+DROP INDEX "profiles_project_id_external_id_key";
+
+-- AlterTable
+ALTER TABLE "profiles" ALTER COLUMN "external_id" DROP NOT NULL;
diff --git a/apps/backend/prisma/schema.prisma b/apps/backend/prisma/schema.prisma
index 0365e482..d40ef1e7 100644
--- a/apps/backend/prisma/schema.prisma
+++ b/apps/backend/prisma/schema.prisma
@@ -69,7 +69,7 @@ model Event {
 
 model Profile {
   id          String  @id @default(dbgenerated("gen_random_uuid()")) @db.Uuid
-  external_id String
+  external_id String?
   first_name  String?
   last_name   String?
   email       String?
@@ -82,7 +82,6 @@ model Profile {
   createdAt DateTime @default(now())
   updatedAt DateTime @default(now()) @updatedAt
 
-  @@unique([project_id, external_id])
   @@map("profiles")
 }
 
diff --git a/apps/backend/src/app.ts b/apps/backend/src/app.ts
index 8c6b5304..88c27d64 100644
--- a/apps/backend/src/app.ts
+++ b/apps/backend/src/app.ts
@@ -1,9 +1,10 @@
-import express from 'express'
+import express, { ErrorRequestHandler } from 'express'
 import events from './routes/events'
 import profiles from './routes/profiles'
 import { authMiddleware } from './middlewares/auth'
 import morgan from 'morgan'
 import { setup } from './routes/setup'
+import { errorHandler } from './middlewares/errors'
 
 const app = express()
 const port = process.env.PORT || 8080
@@ -21,6 +22,9 @@ if (process.env.SETUP) {
 app.use(authMiddleware)
 app.use('/api/sdk', events)
 app.use('/api/sdk', profiles)
+
+app.use(errorHandler)
+
 app.listen(port, () => {
   console.log(`Listening on port ${port}...`)
 })
diff --git a/apps/backend/src/middlewares/auth.ts b/apps/backend/src/middlewares/auth.ts
index d4d239af..1bf182d2 100644
--- a/apps/backend/src/middlewares/auth.ts
+++ b/apps/backend/src/middlewares/auth.ts
@@ -1,14 +1,12 @@
 import { NextFunction, Request, Response } from "express"
 import { db } from "../db"
+import { createError } from "../responses/errors"
 
 export async function authMiddleware(req: Request, res: Response, next: NextFunction) {  
   const secret = req.headers['mixan-client-secret'] as string | undefined
 
   if(!secret) {
-    return res.status(401).json({
-      code: 'UNAUTHORIZED',
-      message: 'Missing client secret',
-    })
+    return next(createError(401, 'Misisng client secret'))
   }
 
   const client = await db.client.findFirst({
@@ -18,10 +16,7 @@ export async function authMiddleware(req: Request, res: Response, next: NextFunc
   })
 
   if(!client) {
-    return res.status(401).json({
-      code: 'UNAUTHORIZED',
-      message: 'Invalid client secret',
-    })
+    return next(createError(401, 'Invalid client secret'))
   }
   
   req.client = {
diff --git a/apps/backend/src/middlewares/errors.ts b/apps/backend/src/middlewares/errors.ts
new file mode 100644
index 00000000..48d89cad
--- /dev/null
+++ b/apps/backend/src/middlewares/errors.ts
@@ -0,0 +1,16 @@
+import { NextFunction, Request, Response } from "express";
+import { HttpError } from "../responses/errors";
+import { MixanErrorResponse } from "@mixan/types";
+
+export const errorHandler = (error: HttpError | Error, req: Request, res: Response, next: NextFunction) => {
+  if(error instanceof HttpError) {
+    return res.status(error.status).json(error.toJson())
+  }
+
+  return res.status(500).json({
+    code: 500,
+    status: 'error',
+    message: error.message || 'Unexpected error occured',
+    issues: []
+  } satisfies MixanErrorResponse);
+};
\ No newline at end of file
diff --git a/apps/backend/src/responses/errors.ts b/apps/backend/src/responses/errors.ts
index 1da9b6f7..1c388b76 100644
--- a/apps/backend/src/responses/errors.ts
+++ b/apps/backend/src/responses/errors.ts
@@ -1,40 +1,38 @@
 import {
   MixanIssue,
-  MixanErrorResponse,
-  MixanIssuesResponse,
+  MixanErrorResponse
 } from '@mixan/types'
 
-export function issues(arr: Array<MixanIssue>): MixanIssuesResponse {
-  return {
-    issues: arr.map((item) => {
-      return {
-        field: item.field,
-        message: item.message,
-        value: item.value,
-      }
-    }),
+export class HttpError extends Error {
+  public status: number
+  public message: string
+  public issues: MixanIssue[]
+
+  constructor(status: number, message: string | Error, issues?: MixanIssue[]) {
+    super(message instanceof Error ? message.message : message)
+    this.status = status
+    this.message = message instanceof Error ? message.message : message
+    this.issues = issues || []
+  }
+
+  toJson(): MixanErrorResponse  {
+    return {
+      code: this.status,
+      status: 'error',
+      message: this.message,
+      issues: this.issues,
+    }
   }
 }
 
-export function makeError(error: unknown): MixanErrorResponse {
-  if (error instanceof Error) {
-    return {
-      code: 'Error',
-      message: error.message,
-    }
-  }
-
-  // @ts-ignore
-  if ('message' in error) {
-    return {
-      code: 'UnknownError',
-      // @ts-ignore
-      message: error.message,
-    }
-  }
-
-  return {
-    code: 'UnknownError',
-    message: 'Unknown error',
-  }
+export function createIssues(arr: Array<MixanIssue>) {
+  throw new HttpError(400, 'Issues', arr)
+}
+
+export function createError(status = 500, error: unknown | Error | string) {
+  if(error instanceof Error || typeof error === 'string') {
+    return new HttpError(status, error)
+  } 
+
+  return new HttpError(500, 'Unexpected error occured')
 }
diff --git a/apps/backend/src/routes/events.ts b/apps/backend/src/routes/events.ts
index 3e010740..79f2a044 100644
--- a/apps/backend/src/routes/events.ts
+++ b/apps/backend/src/routes/events.ts
@@ -1,39 +1,41 @@
-import {Router} from 'express'
+import {NextFunction, Response, Router} from 'express'
 import { db } from '../db';
 import { MixanRequest } from '../types/express';
 import { EventPayload } from '@mixan/types';
-import { getEvents, getProfileIdFromEvents } from '../services/event';
+import { getEvents } from '../services/event';
 import { success } from '../responses/success';
-import { makeError } from '../responses/errors';
 
 const router = Router();
 
 type PostRequest = MixanRequest<Array<EventPayload>>
 
-router.get('/events', async (req, res) => {
+router.get('/events', async (req, res, next) => {
   try {
     const events = await getEvents(req.client.project_id)
     res.json(success(events))
   } catch (error) {
-    res.json(makeError(error))
+    next(error)
   }
 })
 
-router.post('/events', async (req: PostRequest, res) => {
-  const projectId = req.client.project_id
-  const profileId = await getProfileIdFromEvents(projectId, req.body) 
+router.post('/events', async (req: PostRequest, res: Response, next: NextFunction) => {
+  try {
+    const projectId = req.client.project_id
+    
+    await db.event.createMany({
+      data: req.body.map((event) => ({
+        name: event.name,
+        properties: event.properties,
+        createdAt: event.time,
+        project_id: projectId,
+        profile_id: event.profileId,
+      }))
+    })
   
-  await db.event.createMany({
-    data: req.body.map(event => ({
-      name: event.name,
-      properties: event.properties,
-      createdAt: event.time,
-      project_id: projectId,
-      profile_id: profileId,
-    }))
-  })
-
-  res.status(201).json(success())
+    res.status(201).json(success())
+  } catch (error) {
+    next(error)
+  }
 })
 
 export default router
\ No newline at end of file
diff --git a/apps/backend/src/routes/profiles.ts b/apps/backend/src/routes/profiles.ts
index 2dafdc36..ecba0352 100644
--- a/apps/backend/src/routes/profiles.ts
+++ b/apps/backend/src/routes/profiles.ts
@@ -1,132 +1,131 @@
-import { Router } from 'express'
+import { NextFunction, Response, Router } from 'express'
 import { db } from '../db'
 import { MixanRequest } from '../types/express'
-import {
-  createProfile,
-  getProfileByExternalId,
-  updateProfile,
-} from '../services/profile'
+import { getProfile, tickProfileProperty } from '../services/profile'
 import {
   ProfileDecrementPayload,
   ProfileIncrementPayload,
   ProfilePayload,
 } from '@mixan/types'
-import { issues } from '../responses/errors'
 import { success } from '../responses/success'
+import randomAnimalName from 'random-animal-name'
 
 const router = Router()
 
 type PostRequest = MixanRequest<ProfilePayload>
 
-router.get('/profiles', async (req, res) => {
-  res.json(success(await db.profile.findMany({
-    where: {
-      project_id: req.client.project_id,
-    },
-  })))
-})
-
-router.post('/profiles', async (req: PostRequest, res) => {
-  const body = req.body
-  const projectId = req.client.project_id
-  const profile = await getProfileByExternalId(projectId, body.id)
-  if (profile) {
-    await updateProfile(projectId, body.id, body, profile)
-  } else {
-    await createProfile(projectId, body)
+router.get('/profiles', async (req, res, next) => {
+  try {
+    res.json(
+      success(
+        await db.profile.findMany({
+          where: {
+            project_id: req.client.project_id,
+          },
+        })
+      )
+    )
+  } catch (error) {
+    next(error)
   }
-
-  res.status(profile ? 200 : 201).json(success())
 })
 
 router.post(
-  '/profiles/increment',
-  async (req: MixanRequest<ProfileIncrementPayload>, res) => {
-    const body = req.body
-    const projectId = req.client.project_id
-    const profile = await getProfileByExternalId(projectId, body.id)
-
-    if (profile) {
-      const existingProperties = (
-        typeof profile.properties === 'object' ? profile.properties || {} : {}
-      ) as Record<string, number>
-      const value =
-        body.name in existingProperties ? existingProperties[body.name] : 0
-      const properties = {
-        ...existingProperties,
-        [body.name]: value + body.value,
-      }
-
-      if (typeof value !== 'number') {
-        return res.status(400).json(
-          issues([
-            {
-              field: 'name',
-              message: 'Property is not a number',
-              value,
-            },
-          ])
-        )
-      }
-
-      await db.profile.updateMany({
-        where: {
-          external_id: String(body.id),
-          project_id: req.client.project_id,
-        },
+  '/profiles',
+  async (
+    req: MixanRequest<{
+      id: string
+      properties?: Record<string, any>
+    }>,
+    res: Response,
+    next: NextFunction
+  ) => {
+    try {
+      const projectId = req.client.project_id
+      const { id, properties } = req.body
+      const profile = await db.profile.create({
         data: {
-          properties,
+          id,
+          external_id: null,
+          email: null,
+          first_name: randomAnimalName(),
+          last_name: null,
+          avatar: null,
+          properties: {
+            ...(properties || {}),
+          },
+          project_id: projectId,
         },
       })
-    }
 
-    res.status(200).json(success())
+      res.status(201).json(success(profile))
+    } catch (error) {
+      next(error)
+    }
   }
 )
 
-router.post(
-  '/profiles/decrement',
-  async (req: MixanRequest<ProfileDecrementPayload>, res) => {
-    const body = req.body
-    const projectId = req.client.project_id
-    const profile = await getProfileByExternalId(projectId, body.id)
-
+router.put('/profiles/:id', async (req: PostRequest, res: Response, next: NextFunction) => {
+  try {
+    const profileId = req.params.id
+    const profile = await getProfile(profileId)
+    const { body } = req
     if (profile) {
-      const existingProperties = (
-        typeof profile.properties === 'object' ? profile.properties || {} : {}
-      ) as Record<string, number>
-      const value =
-        body.name in existingProperties ? existingProperties[body.name] : 0
-
-        if (typeof value !== 'number') {
-          return res.status(400).json(
-            issues([
-              {
-                field: 'name',
-                message: 'Property is not a number',
-                value,
-              },
-            ])
-          )
-        }
-
-      const properties = {
-        ...existingProperties,
-        [body.name]: value - body.value,
-      }
-
-      await db.profile.updateMany({
+      await db.profile.update({
         where: {
-          external_id: String(body.id),
-          project_id: req.client.project_id,
+          id: profileId,
         },
         data: {
-          properties,
+          external_id: body.id,
+          email: body.email,
+          first_name: body.first_name,
+          last_name: body.last_name,
+          avatar: body.avatar,
+          properties: {
+            ...(typeof profile.properties === 'object'
+              ? profile.properties || {}
+              : {}),
+            ...(body.properties || {}),
+          },
         },
       })
-    }
 
-    res.status(200).json(success())
+      res.status(200).json(success())
+    }
+  } catch (error) {
+    next(error)
+  }
+})
+
+router.put(
+  '/profiles/:id/increment',
+  async (req: MixanRequest<ProfileIncrementPayload>, res: Response, next: NextFunction) => {
+    try {
+      await tickProfileProperty({
+        name: req.body.name,
+        tick: req.body.value,
+        profileId: req.params.id,
+      })
+      res.status(200).json(success())
+    } catch (error) {
+      next(error)
+    }
+  }
+)
+
+router.put(
+  '/profiles/:id/decrement',
+  async (req: MixanRequest<ProfileDecrementPayload>, res: Response, next: NextFunction) => {
+    try {
+      await tickProfileProperty({
+        name: req.body.name,
+        tick: -Math.abs(req.body.value),
+        profileId: req.params.id,
+      })
+      res.status(200).json(success())
+    } catch (error) {
+      next(error)
+    }
   }
 )
 
diff --git a/apps/backend/src/routes/setup.ts b/apps/backend/src/routes/setup.ts
index c65c5d71..8e9527bb 100644
--- a/apps/backend/src/routes/setup.ts
+++ b/apps/backend/src/routes/setup.ts
@@ -1,9 +1,8 @@
-import { Request, Response } from 'express'
+import { NextFunction, Request, Response } from 'express'
 import { db } from '../db'
-import { makeError } from '../responses/errors'
 import { v4 as uuid } from 'uuid'
 
-export async function setup(req: Request, res: Response) {
+export async function setup(req: Request, res: Response, next: NextFunction) {
   try {
     const organization = await db.organization.create({
       data: {
@@ -22,7 +21,7 @@ export async function setup(req: Request, res: Response) {
       data: {
         name: 'Acme Website Client',
         project_id: project.id,
-        secret: uuid(),
+        secret: '4bfc4a0b-37e0-4916-b634-95c6a32a2e77',
       },
     })
 
@@ -32,6 +31,6 @@ export async function setup(req: Request, res: Response) {
       client,
     })
   } catch (error) {
-    res.json(makeError(error))
+    next(error)
   }
 }
diff --git a/apps/backend/src/services/event.ts b/apps/backend/src/services/event.ts
index 3008e44f..537ac410 100644
--- a/apps/backend/src/services/event.ts
+++ b/apps/backend/src/services/event.ts
@@ -1,4 +1,3 @@
-import { EventPayload } from "@mixan/types";
 import { db } from "../db";
 
 export function getEvents(projectId: string) {
@@ -8,22 +7,3 @@ export function getEvents(projectId: string) {
     }
   })
 }
-
-export async function getProfileIdFromEvents(projectId: string, events: EventPayload[]) {
-  const event = events.find(item => !!item.externalId)
-  if(event?.externalId) {
-    return db.profile.findUnique({
-      where: {
-        project_id_external_id: {
-          project_id: projectId,
-          external_id: event.externalId,
-        }
-      }
-    }).then((res) => {
-      return res?.id || null
-    }).catch(() => {
-      return null
-    })
-  }
-  return null
-}
diff --git a/apps/backend/src/services/password.ts b/apps/backend/src/services/password.ts
deleted file mode 100644
index a084a350..00000000
--- a/apps/backend/src/services/password.ts
+++ /dev/null
@@ -1,7 +0,0 @@
-export async function hashPassword(password: string) {
-  return await Bun.password.hash(password);
-}
-
-export async function verifyPassword(password: string,hashedPassword: string) {
-  return await Bun.password.verify(password, hashedPassword);
-}
\ No newline at end of file
diff --git a/apps/backend/src/services/profile.ts b/apps/backend/src/services/profile.ts
index 363d7854..776afe6d 100644
--- a/apps/backend/src/services/profile.ts
+++ b/apps/backend/src/services/profile.ts
@@ -1,32 +1,15 @@
-import { EventPayload, ProfilePayload } from "@mixan/types";
-import { db } from "../db";
-import { Prisma } from "@prisma/client";
+import { EventPayload, ProfilePayload } from '@mixan/types'
+import { db } from '../db'
+import { Prisma } from '@prisma/client'
+import { HttpError } from '../responses/errors'
 
-export function createProfile(projectId: string, payload: ProfilePayload) {
-  const { id, email, first_name, last_name, avatar, properties } = payload
-  return db.profile.create({
-    data:{
-      external_id: id,
-      email,
-      first_name,
-      last_name,
-      avatar,
-      properties: properties || {},
-      project_id: projectId,
-    }
-  })
-}
+type DbProfile = Exclude<Prisma.PromiseReturnType<typeof getProfile>, null>
 
-type DbProfile = Exclude<Prisma.PromiseReturnType<typeof getProfileByExternalId>, null>
-
-export function getProfileByExternalId(projectId: string, externalId: string) {
-  return db.profile.findUnique({
+export function getProfile(id: string) {
+  return db.profile.findUniqueOrThrow({
     where: {
-      project_id_external_id: {
-        project_id: projectId,
-        external_id: externalId,
-      }
-    }
+      id,
+    },
   })
 }
 
@@ -34,42 +17,47 @@ export function getProfiles(projectId: string) {
   return db.profile.findMany({
     where: {
       project_id: projectId,
-    }
+    },
   })
 }
 
-export async function updateProfile(projectId: string, profileId: string, payload: Omit<ProfilePayload, 'id'>, oldProfile: DbProfile) {
-  const { email, first_name, last_name, avatar, properties } = payload
-  return db.profile.update({
+export async function tickProfileProperty({
+  profileId,
+  tick,
+  name,
+}: {
+  profileId: string
+  tick: number
+  name: string
+}) {
+  const profile = await getProfile(profileId)
+
+  if (!profile) {
+    throw new HttpError(404, `Profile not found ${profileId}`)
+  }
+
+  const properties = (
+    typeof profile.properties === 'object' ? profile.properties || {} : {}
+  ) as Record<string, number>
+  const value = name in properties ? properties[name] : 0
+
+  if (typeof value !== 'number') {
+    throw new HttpError(400, `Property "${name}" on user is of type ${typeof value}`)
+  }
+  
+  if (typeof tick !== 'number') {
+    throw new HttpError(400, `Value is not a number ${tick} (${typeof tick})`)
+  }
+
+  await db.profile.update({
     where: {
-      project_id_external_id: {
-        project_id: projectId,
-        external_id: profileId,
-      }
+      id: profileId,
     },
     data: {
-      email,
-      first_name,
-      last_name,
-      avatar,
       properties: {
-        ...(typeof oldProfile.properties === 'object' ? oldProfile.properties || {} : {}),
-        ...(properties || {}),
+        ...properties,
+        [name]: value + tick,
       },
     },
   })
 }
-
-export async function getInternalProfileId(profileId?: string | null) {
-  if(!profileId) {
-    return null
-  }
-
-  const profile = await db.profile.findFirst({
-    where: {
-      external_id: profileId,
-    }
-  })
-
-  return profile?.id || null
-}
\ No newline at end of file
diff --git a/apps/backend/src/types/express.ts b/apps/backend/src/types/express.ts
index f849b01e..7331a4bb 100644
--- a/apps/backend/src/types/express.ts
+++ b/apps/backend/src/types/express.ts
@@ -1,3 +1,5 @@
-export type MixanRequest<Body> = Omit<Express.Request,'body'> & {
+import { Request } from "express"
+
+export type MixanRequest<Body> = Omit<Request,'body'> & {
   body: Body
 }
\ No newline at end of file
diff --git a/bun.lockb b/bun.lockb
index 898ec7ef..73621efd 100755
Binary files a/bun.lockb and b/bun.lockb differ
diff --git a/packages/sdk/index.ts b/packages/sdk/index.ts
index 352f089e..86d9f714 100644
--- a/packages/sdk/index.ts
+++ b/packages/sdk/index.ts
@@ -1,7 +1,7 @@
+import { v4 as uuid } from 'uuid'
 import {
   EventPayload,
   MixanErrorResponse,
-  MixanIssuesResponse,
   MixanResponse,
   ProfilePayload,
 } from '@mixan/types'
@@ -12,6 +12,9 @@ type MixanOptions = {
   batchInterval?: number
   maxBatchSize?: number
   verbose?: boolean
+  saveProfileId: (profileId: string) => void,
+  getProfileId: () => string | null,
+  removeProfileId: () => void,
 }
 
 class Fetcher {
@@ -25,7 +28,11 @@ class Fetcher {
     this.logger = options.verbose ? console.log : () => {}
   }
 
-  post(path: string, data: Record<string, any>) {
+  post(
+    path: string,
+    data: Record<string, any>,
+    options: FetchRequestInit = {}
+  ) {
     const url = `${this.url}${path}`
     this.logger(`Mixan request: ${url}`, JSON.stringify(data, null, 2))
     return fetch(url, {
@@ -35,30 +42,19 @@ class Fetcher {
       },
       method: 'POST',
       body: JSON.stringify(data),
+      ...options,
     })
       .then(async (res) => {
         const response = await res.json<
-          MixanIssuesResponse | MixanErrorResponse | MixanResponse<unknown>
+          MixanErrorResponse | MixanResponse<unknown>
         >()
-        if ('status' in response && response.status === 'ok') {
-          return response
-        }
 
-        if ('code' in response) {
-          this.logger(`Mixan error: [${response.code}] ${response.message}`)
+        if('status' in response && response.status === 'error') {
+          this.logger(`Mixan request failed: ${url}`, JSON.stringify(response, null, 2))
           return null
         }
-
-        if ('issues' in response) {
-          this.logger(`Mixan issues:`)
-          response.issues.forEach((issue) => {
-            this.logger(`  - ${issue.message} (${issue.value})`)
-          })
-
-          return null
-        }
-
-        return null
+        
+        return response
       })
       .catch(() => {
         return null
@@ -99,7 +95,7 @@ class Batcher<T extends any> {
       return
     }
 
-    if (this.queue.length > this.maxBatchSize) {
+    if (this.queue.length >= this.maxBatchSize) {
       this.send()
       return
     }
@@ -116,16 +112,21 @@ class Batcher<T extends any> {
 export class Mixan {
   private fetch: Fetcher
   private eventBatcher: Batcher<EventPayload>
-  private profile: ProfilePayload | null = null
-
+  private profileId?: string
+  private options: MixanOptions
+  private logger: (...args: any[]) => void
+  
   constructor(options: MixanOptions) {
+    this.logger = options.verbose ? console.log : () => {}
+    this.options = options
     this.fetch = new Fetcher(options)
+    this.setAnonymousUser()
     this.eventBatcher = new Batcher(options, (queue) => {
       this.fetch.post(
         '/events',
         queue.map((item) => ({
           ...item,
-          externalId: item.externalId || this.profile?.id,
+          profileId: item.profileId || this.profileId || null,
         }))
       )
     })
@@ -140,18 +141,34 @@ export class Mixan {
       name,
       properties,
       time: this.timestamp(),
-      externalId: this.profile?.id || null,
+      profileId: this.profileId || null,
     })
   }
 
+  private setAnonymousUser() {
+    const profileId = this.options.getProfileId()
+    if(profileId) {
+      this.profileId = profileId
+       this.logger('Use existing ID', this.profileId);
+    } else {
+      this.profileId = uuid()
+       this.logger('Create new ID', this.profileId);
+      this.options.saveProfileId(this.profileId)
+      this.fetch.post('/profiles', {
+        id: this.profileId,
+        properties: {},
+      })
+    }
+  }
+
   async setUser(profile: ProfilePayload) {
-    this.profile = profile
-    await this.fetch.post('/profiles', profile)
+    await this.fetch.post(`/profiles/${this.profileId}`, profile, {
+      method: 'PUT'
+    })
   }
 
   async setUserProperty(name: string, value: any) {
-    await this.fetch.post('/profiles', {
-      ...this.profile,
+    await this.fetch.post(`/profiles/${this.profileId}`, {
       properties: {
         [name]: value,
       },
@@ -159,33 +176,41 @@ export class Mixan {
   }
 
   async increment(name: string, value: number = 1) {
-    if (!this.profile) {
+    if (!this.profileId) {
       return
     }
 
-    await this.fetch.post('/profiles/increment', {
-      id: this.profile.id,
+    await this.fetch.post(`/profiles/${this.profileId}/increment`, {
       name,
       value,
+    }, {
+      method: 'PUT'
     })
   }
 
   async decrement(name: string, value: number = 1) {
-    if (!this.profile) {
+    if (!this.profileId) {
       return
     }
 
-    await this.fetch.post('/profiles/decrement', {
-      id: this.profile.id,
+    await this.fetch.post(`/profiles/${this.profileId}/decrement`, {
       name,
       value,
+    }, {
+      method: 'PUT'
     })
   }
 
-  screenView(route: string, properties?: Record<string, any>) {
-    this.event('screen_view', {
+  async screenView(route: string, properties?: Record<string, any>) {
+    await this.event('screen_view', {
       ...(properties || {}),
       route,
     })
   }
+
+  clear() {
+    this.eventBatcher.flush()
+    this.options.removeProfileId()
+    this.profileId = undefined
+  }
 }
diff --git a/packages/sdk/package.json b/packages/sdk/package.json
index 58c586dd..9797592a 100644
--- a/packages/sdk/package.json
+++ b/packages/sdk/package.json
@@ -4,9 +4,11 @@
   "type": "module",
   "module": "index.ts",
   "dependencies": {
-    "@mixan/types": "workspace:*"
+    "@mixan/types": "workspace:*",
+    "uuid": "^9.0.1"
   },
   "devDependencies": {
+    "@types/uuid": "^9.0.5",
     "bun-types": "latest",
     "typescript": "^5.0.0"
   }
diff --git a/packages/types/index.ts b/packages/types/index.ts
index 00f756e1..43fb84f2 100644
--- a/packages/types/index.ts
+++ b/packages/types/index.ts
@@ -3,7 +3,7 @@ export type MixanJson = Record<string, any>
 export type EventPayload = {
   name: string
   time: string
-  externalId: string | null
+  profileId: string | null
   properties: MixanJson
 }
 
@@ -12,8 +12,8 @@ export type ProfilePayload = {
   last_name?: string
   email?: string
   avatar?: string
-  id: string
-  properties: MixanJson
+  id?: string
+  properties?: MixanJson
 }
 
 export type ProfileIncrementPayload = {
@@ -59,13 +59,11 @@ export type MixanIssue = {
   value: any
 }
 
-export type MixanIssuesResponse = {
-  issues: Array<MixanIssue>,
-}
-
 export type MixanErrorResponse = {
-  code: string
+  status: 'error'
+  code: number
   message: string
+  issues: Array<MixanIssue>
 }
 
 export type MixanResponse<T> = {