Add Memories

Add facts, messages, or metadata to a user memory store with async processing and event tracking via the V3 additive pipeline.

POST /v3/memories/add/

cURL

cURL

curl -X POST https://api.mem0.ai/v3/memories/add/ \
  -H "Authorization: Token <api-key>" \
  -H "Content-Type: application/json" \
  -d '{
    "messages": [
      {"role": "user", "content": "I just moved to San Francisco from New York."},
      {"role": "assistant", "content": "Got it, I\u0027ll update your location."}
    ],
    "user_id": "alice"
  }'

from mem0 import MemoryClient

client = MemoryClient(api_key="your-api-key")

result = client.add(
    messages=[
        {"role": "user", "content": "I just moved to San Francisco from New York."},
        {"role": "assistant", "content": "Got it, I'll update your location."}
    ],
    user_id="alice",
)
print(result)

import MemoryClient from "mem0ai";

const client = new MemoryClient({ apiKey: "your-api-key" });

const result = await client.add(
  [
    { role: "user", content: "I just moved to San Francisco from New York." },
    { role: "assistant", content: "Got it, I'll update your location." },
  ],
  { userId: "alice" }
);
console.log(result);

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.mem0.ai/v3/memories/add/",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'messages' => [
        [
                'role' => 'user',
                'content' => 'I just moved to San Francisco from New York.'
        ],
        [
                'role' => 'assistant',
                'content' => 'Got it, I\'ll update your location.'
        ]
    ],
    'user_id' => 'alice'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.mem0.ai/v3/memories/add/"

	payload := strings.NewReader("{\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"I just moved to San Francisco from New York.\"\n    },\n    {\n      \"role\": \"assistant\",\n      \"content\": \"Got it, I'll update your location.\"\n    }\n  ],\n  \"user_id\": \"alice\"\n}")

	req, _ := http.NewRequest("POST", url, payload)

	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.post("https://api.mem0.ai/v3/memories/add/")
  .header("Content-Type", "application/json")
  .body("{\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"I just moved to San Francisco from New York.\"\n    },\n    {\n      \"role\": \"assistant\",\n      \"content\": \"Got it, I'll update your location.\"\n    }\n  ],\n  \"user_id\": \"alice\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.mem0.ai/v3/memories/add/")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Post.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"messages\": [\n    {\n      \"role\": \"user\",\n      \"content\": \"I just moved to San Francisco from New York.\"\n    },\n    {\n      \"role\": \"assistant\",\n      \"content\": \"Got it, I'll update your location.\"\n    }\n  ],\n  \"user_id\": \"alice\"\n}"

response = http.request(request)
puts response.read_body

200

{
  "message": "Memory processing has been queued for background execution",
  "status": "PENDING",
  "event_id": "2c4d1f44-4f7b-4b2f-9f6e-7b5b4f5a1234"
}

Extract and store memories from a conversation using the V3 additive pipeline. The endpoint uses single-pass ADD-only extraction: one LLM call, no UPDATE/DELETE. Memories accumulate over time; nothing is overwritten.

Endpoint

• Method: POST
• URL: /v3/memories/add/
• Content-Type: application/json

Processing is asynchronous. The response returns an event_id you can poll via GET /v1/event/{event_id}/.

Required headers

Header	Required	Description
Authorization: Token <MEM0_API_KEY>	Yes	API key scoped to your workspace.
Accept: application/json	Yes	Ensures a JSON response.

Request body

Provide conversation messages for Mem0 to extract memories from. At least one entity ID (user_id, agent_id, app_id, or run_id) is required so the memory is scoped to a session. Entity IDs are accepted at the top level.

Basic request

{
  "user_id": "alice",
  "messages": [
    { "role": "user", "content": "I moved to Austin last month." }
  ],
  "metadata": {
    "source": "onboarding_form"
  }
}

Common fields

Field	Type	Required	Description
messages	array	Yes	Conversation turns for Mem0 to extract memories from. Each object should include role and content.
user_id	string	No*	Associates the memory with a user.
agent_id	string	No*	Associates the memory with an agent.
run_id	string	No*	Associates the memory with a run.
app_id	string	No*	Associates the memory with an app.
metadata	object	Optional	Custom key/value metadata (e.g., {"topic": "preferences"}).
infer	boolean (default true)	Optional	Set to false to skip inference and store the provided text as-is.
expiration_date	string	Optional	Date in YYYY-MM-DD format. The memory is visible through this date and hidden by default after it passes.

* At least one entity ID (user_id, agent_id, app_id, or run_id) is required.

Need more details? See all request parameters below for complete field descriptions, types, and constraints.

Response

The request is queued for background processing. The response contains an event_id for tracking status.

200 response

{
  "message": "Memory processing has been queued for background execution",
  "status": "PENDING",
  "event_id": "evt-uuid"
}

{
  "error": "400 Bad Request",
  "details": {
    "message": "Invalid input data. Please refer to the memory creation documentation at https://docs.mem0.ai/platform/quickstart#4-1-create-memories for correct formatting and required fields."
  }
}

Poll the event status via GET /v1/event/{event_id}/. Status will be SUCCEEDED or FAILED once processing completes.

Memories with expiration_date remain stored after they expire. Search and get-all hide them by default; pass show_expired: true to include them.

Python uses expiration_date; TypeScript uses expirationDate.

Body

application/json

messages · object[] · required

Conversation messages to extract memories from.

Show child attributes

user_id · string

Scope memories to this user.

agent_id · string

Scope memories to this agent.

run_id · string

Scope memories to this session / run.

metadata · object

User-supplied metadata to attach to each extracted memory.

expiration_date · string<date> | null

Optional expiration date in YYYY-MM-DD format. After this date, memories are hidden from search and get-all unless show_expired is true.

custom_instructions · string

Project-level instructions that guide extraction for this call.

custom_categories · object[]

Category catalog for this call. Replaces the project-level list rather than merging with it. Omit to fall back to the project list, then the default catalog.

Show child attributes

infer · boolean · default: true

When false, stores each message verbatim without running the extraction LLM.

Response

200

application/json

Memory addition queued; returns an event identifier clients can poll via GET /v1/event/{event_id}/.

message · string

status · enum<string>

Available options: PENDING, SUCCEEDED, FAILED

event_id · string<uuid>