Validate email deliverability

curl --request POST \
  --url https://brew.new/api/v1/contacts/validate \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "emails": [
    "ada@gmail.com",
    "temp@mailinator.com",
    "admin@stripe.com"
  ]
}
'

import requests

url = "https://brew.new/api/v1/contacts/validate"

payload = { "emails": ["ada@gmail.com", "temp@mailinator.com", "admin@stripe.com"] }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({emails: ['ada@gmail.com', 'temp@mailinator.com', 'admin@stripe.com']})
};

fetch('https://brew.new/api/v1/contacts/validate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://brew.new/api/v1/contacts/validate",
  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([
    'emails' => [
        'ada@gmail.com',
        'temp@mailinator.com',
        'admin@stripe.com'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "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://brew.new/api/v1/contacts/validate"

	payload := strings.NewReader("{\n  \"emails\": [\n    \"ada@gmail.com\",\n    \"temp@mailinator.com\",\n    \"admin@stripe.com\"\n  ]\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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://brew.new/api/v1/contacts/validate")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"emails\": [\n    \"ada@gmail.com\",\n    \"temp@mailinator.com\",\n    \"admin@stripe.com\"\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://brew.new/api/v1/contacts/validate")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"emails\": [\n    \"ada@gmail.com\",\n    \"temp@mailinator.com\",\n    \"admin@stripe.com\"\n  ]\n}"

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

{
  "data": [
    {
      "email": "ada@gmail.com",
      "valid": true,
      "status": "valid"
    },
    {
      "email": "temp@mailinator.com",
      "valid": false,
      "status": "invalid",
      "reason": "undeliverable"
    },
    {
      "email": "ada@gmial.com",
      "valid": false,
      "status": "risky",
      "reason": "unknown",
      "didYouMean": "ada@gmail.com"
    },
    {
      "email": "admin@stripe.com",
      "valid": false,
      "status": "risky",
      "reason": "role_address"
    }
  ]
}

{
  "error": {
    "code": "INVALID_REQUEST",
    "type": "invalid_request",
    "message": "Request validation failed.",
    "suggestion": "Fix the field reported in `param` and retry.",
    "docs": "https://docs.brew.new/api-reference/api/errors",
    "param": "emails"
  }
}

{
  "error": {
    "code": "INVALID_API_KEY",
    "type": "authentication_error",
    "message": "The provided API key is invalid.",
    "suggestion": "Check the API key format and retry with a valid active key.",
    "docs": "https://docs.brew.new/api-reference/api/authentication"
  }
}

{
  "error": {
    "code": "INSUFFICIENT_CREDITS",
    "type": "payment_required",
    "message": "This operation required more credits than the 0 remaining on the 'free' plan. See the per-operation cost in GET /v1/help.",
    "suggestion": "Upgrade your plan or wait for the next billing period to reset. Check your balance up front with GET /v1/usage.",
    "docs": "https://docs.brew.new/api-reference/api/credits",
    "details": {
      "cost": 2,
      "remaining": 0,
      "planKey": "free"
    }
  }
}

{
  "error": {
    "code": "INSUFFICIENT_PERMISSIONS",
    "type": "authorization_error",
    "message": "The caller does not have the required permission.",
    "suggestion": "Use an API key or session with the required permission.",
    "docs": "https://docs.brew.new/api-reference/api/authentication",
    "param": "contacts"
  }
}

{
  "error": {
    "code": "RATE_LIMITED",
    "type": "rate_limit",
    "message": "Too many requests.",
    "suggestion": "Wait for the retry window before sending another request.",
    "docs": "https://docs.brew.new/api-reference/api/rate-limits",
    "retryAfter": 42
  }
}

{
  "error": {
    "code": "INTERNAL_ERROR",
    "type": "internal_error",
    "message": "An unexpected error occurred.",
    "suggestion": "Retry the request. If it keeps failing, contact support.",
    "docs": "https://docs.brew.new/api-reference/api/errors"
  }
}

{
  "error": {
    "code": "SERVICE_UNAVAILABLE",
    "type": "service_unavailable",
    "message": "Your credit balance could not be verified because a billing dependency is temporarily unavailable.",
    "suggestion": "Retry the request after a short delay.",
    "docs": "https://docs.brew.new/api-reference/api/credits",
    "retryAfter": 2
  }
}

Contacts

Validate email deliverability

Batch deliverability check (up to 100 addresses) — run BEFORE importing or sending. Each address is classified valid (safe), risky (deliverable but flagged — e.g. role account, disposable, catch-all), or invalid (undeliverable / do-not-send), with a machine-readable reason and a didYouMean typo correction when applicable. Cost: 2 credits PER ADDRESS (X-Credit-Cost = 2 × the number of addresses), charged ONLY on success — if the check cannot complete for the whole batch, the call returns a retryable 503 and is NOT billed.

POST

contacts

validate

curl --request POST \
  --url https://brew.new/api/v1/contacts/validate \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "emails": [
    "ada@gmail.com",
    "temp@mailinator.com",
    "admin@stripe.com"
  ]
}
'

import requests

url = "https://brew.new/api/v1/contacts/validate"

payload = { "emails": ["ada@gmail.com", "temp@mailinator.com", "admin@stripe.com"] }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({emails: ['ada@gmail.com', 'temp@mailinator.com', 'admin@stripe.com']})
};

fetch('https://brew.new/api/v1/contacts/validate', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://brew.new/api/v1/contacts/validate",
  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([
    'emails' => [
        'ada@gmail.com',
        'temp@mailinator.com',
        'admin@stripe.com'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "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://brew.new/api/v1/contacts/validate"

	payload := strings.NewReader("{\n  \"emails\": [\n    \"ada@gmail.com\",\n    \"temp@mailinator.com\",\n    \"admin@stripe.com\"\n  ]\n}")

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

	req.Header.Add("Authorization", "Bearer <token>")
	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://brew.new/api/v1/contacts/validate")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"emails\": [\n    \"ada@gmail.com\",\n    \"temp@mailinator.com\",\n    \"admin@stripe.com\"\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://brew.new/api/v1/contacts/validate")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"emails\": [\n    \"ada@gmail.com\",\n    \"temp@mailinator.com\",\n    \"admin@stripe.com\"\n  ]\n}"

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

{
  "data": [
    {
      "email": "ada@gmail.com",
      "valid": true,
      "status": "valid"
    },
    {
      "email": "temp@mailinator.com",
      "valid": false,
      "status": "invalid",
      "reason": "undeliverable"
    },
    {
      "email": "ada@gmial.com",
      "valid": false,
      "status": "risky",
      "reason": "unknown",
      "didYouMean": "ada@gmail.com"
    },
    {
      "email": "admin@stripe.com",
      "valid": false,
      "status": "risky",
      "reason": "role_address"
    }
  ]
}

{
  "error": {
    "code": "INVALID_REQUEST",
    "type": "invalid_request",
    "message": "Request validation failed.",
    "suggestion": "Fix the field reported in `param` and retry.",
    "docs": "https://docs.brew.new/api-reference/api/errors",
    "param": "emails"
  }
}

{
  "error": {
    "code": "INVALID_API_KEY",
    "type": "authentication_error",
    "message": "The provided API key is invalid.",
    "suggestion": "Check the API key format and retry with a valid active key.",
    "docs": "https://docs.brew.new/api-reference/api/authentication"
  }
}

{
  "error": {
    "code": "INSUFFICIENT_CREDITS",
    "type": "payment_required",
    "message": "This operation required more credits than the 0 remaining on the 'free' plan. See the per-operation cost in GET /v1/help.",
    "suggestion": "Upgrade your plan or wait for the next billing period to reset. Check your balance up front with GET /v1/usage.",
    "docs": "https://docs.brew.new/api-reference/api/credits",
    "details": {
      "cost": 2,
      "remaining": 0,
      "planKey": "free"
    }
  }
}

{
  "error": {
    "code": "INSUFFICIENT_PERMISSIONS",
    "type": "authorization_error",
    "message": "The caller does not have the required permission.",
    "suggestion": "Use an API key or session with the required permission.",
    "docs": "https://docs.brew.new/api-reference/api/authentication",
    "param": "contacts"
  }
}

{
  "error": {
    "code": "RATE_LIMITED",
    "type": "rate_limit",
    "message": "Too many requests.",
    "suggestion": "Wait for the retry window before sending another request.",
    "docs": "https://docs.brew.new/api-reference/api/rate-limits",
    "retryAfter": 42
  }
}

{
  "error": {
    "code": "INTERNAL_ERROR",
    "type": "internal_error",
    "message": "An unexpected error occurred.",
    "suggestion": "Retry the request. If it keeps failing, contact support.",
    "docs": "https://docs.brew.new/api-reference/api/errors"
  }
}

{
  "error": {
    "code": "SERVICE_UNAVAILABLE",
    "type": "service_unavailable",
    "message": "Your credit balance could not be verified because a billing dependency is temporarily unavailable.",
    "suggestion": "Retry the request after a short delay.",
    "docs": "https://docs.brew.new/api-reference/api/credits",
    "retryAfter": 2
  }
}

Authorizations

Authorization

string

header

default:Bearer brew_your_api_key

required

Send your Brew API key as Authorization: Bearer brew_xxx.

Body

application/json

emails

string[]

required

Required array length: 1 - 100 elements

Minimum string length: 1

Response

One classification row per input address.

data

object[]

required

Show child attributes

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Overview

Core concepts

Guides

MCP server

CLI

Public API v1

Validate email deliverability

Authorizations

Body

Response