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POST Request an email proof for the browser entry

/api/v1/auth/entry/email/request

Requests a ten-minute magic link and six-digit code bound to the requesting browser. An active verified account can sign in regardless of the registration gate. A new human account is created only when registration and its rate limits permit; successful proof still requires current legal consent. The 202 reply does not disclose whether mail was sent. Resending within 60 seconds returns the existing challenge; later requests replace that browser flow only.

On this page

Access and permissions

Requests a ten-minute magic link and six-digit code bound to the requesting browser. An active verified account can sign in regardless of the registration gate. A new human account is created only when registration and its rate limits permit; successful proof still requires current legal consent. The 202 reply does not disclose whether mail was sent. Resending within 60 seconds returns the existing challenge; later requests replace that browser flow only.

No account sign-in is required. Any listed browser-origin checks and rate limits still apply.

Parameters and headers

FieldLocationType and limitsRequiredMeaning
OriginHeaderstring; {"format":"uri"}YesThe same HTTPS origin as the public browser site. Required for browser login and provider-start requests.

Request body

FieldType and limitsRequiredMeaning
$object; {"additionalProperties":false}Yes—
$.emailstring; {"format":"email","maxLength":254}YesEmail address of the account or operation target. Confirmation rules depend on the operation.
$.return_tostringNoAllowed local destination after sign-in. External and unsafe destinations are rejected.

Responses

HeaderType and limitsMeaning
Cache-Controlstring; {"pattern":"(?:^|,\\s*)no-store(?:,|$)"}Private API responses prohibit storage. Public OAuth metadata is cached for 300 seconds; live streams additionally prohibit transformation.
Content-Languagestring; {"enum":["en","de"]}Language of human-readable response text, resolved from Accept-Language or the documented browser preference. Technical codes and identifiers remain stable.
Referrer-PolicyJSON; {"enum":["strict-origin-when-cross-origin","no-referrer"]}The default referrer policy is strict-origin-when-cross-origin. Provider-login responses use no-referrer to protect login parameters.
VarystringResponses vary by Accept-Language; browser-rendered responses can also vary by the preference cookie.
X-Content-Type-OptionsJSON; {"const":"nosniff"}The browser must use the declared content type.
X-Frame-OptionsJSON; {"const":"DENY"}The response must not be embedded in a frame.
X-Request-IDstringServer-generated request identifier. Include this when reporting an error; inbound values are not trusted.

application/json

FieldType and limitsRequiredMeaning
$EntryFlowYes—
$.challenge_idstring; {"format":"uuid"}NoUUID of the challenge issued to this browser or machine request.
$.emailstring; {"format":"email"}YesEmail address of the account or operation target. Confirmation rules depend on the operation.
$.email_verifiedbooleanYes—
$.expires_atstring; {"format":"date-time"}YesExpiry timestamp. A successful request does not extend this deadline unless explicitly documented.
$.mail_verifiedbooleanYes—
$.privacy_versionstringNoSHA-256 version returned for the currently published privacy text.
$.providerstring; {"enum":["","google","github"]}YesConfigured identity provider. Availability must be read from the providers endpoint.
$.resend_atstring; {"format":"date-time"}No—
$.return_tostringYesAllowed local destination after sign-in. External and unsafe destinations are rejected.
$.statusstring; {"enum":["verification_required","consent_required","link_confirmation_required"]}Yes—
$.terms_versionstringNoSHA-256 version returned for the currently published terms. Retrieve the current text before accepting.
json
{
  "email": "demo@example.com",
  "email_verified": false,
  "expires_at": "2026-09-30T12:00:00Z",
  "mail_verified": false,
  "provider": "",
  "return_to": "demo",
  "status": "verification_required"
}
Stable error codes
invalid_origin
HeaderType and limitsMeaning
Cache-Controlstring; {"pattern":"(?:^|,\\s*)no-store(?:,|$)"}Private API responses prohibit storage. Public OAuth metadata is cached for 300 seconds; live streams additionally prohibit transformation.
Content-Languagestring; {"enum":["en","de"]}Language of human-readable response text, resolved from Accept-Language or the documented browser preference. Technical codes and identifiers remain stable.
Referrer-PolicyJSON; {"enum":["strict-origin-when-cross-origin","no-referrer"]}The default referrer policy is strict-origin-when-cross-origin. Provider-login responses use no-referrer to protect login parameters.
VarystringResponses vary by Accept-Language; browser-rendered responses can also vary by the preference cookie.
X-Content-Type-OptionsJSON; {"const":"nosniff"}The browser must use the declared content type.
X-Frame-OptionsJSON; {"const":"DENY"}The response must not be embedded in a frame.
X-Request-IDstringServer-generated request identifier. Include this when reporting an error; inbound values are not trusted.

application/problem+json

FieldType and limitsRequiredMeaning
$ProblemYes—
$.codestringYesStable machine-readable error code
$.detailstringYesShort localized explanation without internal error details
$.instancestringYesUnique relative identifier /api/v1/requests/{request_id}; not a retrievable resource
$.messagestringYesTemporarily identical to detail for existing clients
$.message_keystringYesStable translation key for changing the displayed language without another request
$.message_paramsobject; {"additionalProperties":true}YesNamed, safely rendered message parameters; never arbitrary HTML
$.request_idstring; {"pattern":"^[0-9a-f]{32}$"}YesServer-generated diagnostic identifier. It contains no login token or credential.
$.statusinteger; {"maximum":599,"minimum":400}Yes—
$.titlestringYesLocalized HTTP status title
$.typestring; {"const":"about:blank"}Yes—
json
{
  "code": "demo",
  "detail": "Demo error detail; inspect the documented code.",
  "instance": "demo",
  "message": "Demo error detail; inspect the documented code.",
  "message_key": "errors.requestFailed",
  "message_params": {},
  "request_id": "00000000000000000000000000000000",
  "status": 403,
  "title": "Demo error",
  "type": "about:blank"
}
Stable error codes
invalid_input
invalid_return_to
HeaderType and limitsMeaning
Cache-Controlstring; {"pattern":"(?:^|,\\s*)no-store(?:,|$)"}Private API responses prohibit storage. Public OAuth metadata is cached for 300 seconds; live streams additionally prohibit transformation.
Content-Languagestring; {"enum":["en","de"]}Language of human-readable response text, resolved from Accept-Language or the documented browser preference. Technical codes and identifiers remain stable.
Referrer-PolicyJSON; {"enum":["strict-origin-when-cross-origin","no-referrer"]}The default referrer policy is strict-origin-when-cross-origin. Provider-login responses use no-referrer to protect login parameters.
VarystringResponses vary by Accept-Language; browser-rendered responses can also vary by the preference cookie.
X-Content-Type-OptionsJSON; {"const":"nosniff"}The browser must use the declared content type.
X-Frame-OptionsJSON; {"const":"DENY"}The response must not be embedded in a frame.
X-Request-IDstringServer-generated request identifier. Include this when reporting an error; inbound values are not trusted.

application/problem+json

FieldType and limitsRequiredMeaning
$ProblemYes—
$.codestringYesStable machine-readable error code
$.detailstringYesShort localized explanation without internal error details
$.instancestringYesUnique relative identifier /api/v1/requests/{request_id}; not a retrievable resource
$.messagestringYesTemporarily identical to detail for existing clients
$.message_keystringYesStable translation key for changing the displayed language without another request
$.message_paramsobject; {"additionalProperties":true}YesNamed, safely rendered message parameters; never arbitrary HTML
$.request_idstring; {"pattern":"^[0-9a-f]{32}$"}YesServer-generated diagnostic identifier. It contains no login token or credential.
$.statusinteger; {"maximum":599,"minimum":400}Yes—
$.titlestringYesLocalized HTTP status title
$.typestring; {"const":"about:blank"}Yes—
json
{
  "code": "demo",
  "detail": "Demo error detail; inspect the documented code.",
  "instance": "demo",
  "message": "Demo error detail; inspect the documented code.",
  "message_key": "errors.requestFailed",
  "message_params": {},
  "request_id": "00000000000000000000000000000000",
  "status": 422,
  "title": "Demo error",
  "type": "about:blank"
}
Stable error codes
auth_unavailable
HeaderType and limitsMeaning
Cache-Controlstring; {"pattern":"(?:^|,\\s*)no-store(?:,|$)"}Private API responses prohibit storage. Public OAuth metadata is cached for 300 seconds; live streams additionally prohibit transformation.
Content-Languagestring; {"enum":["en","de"]}Language of human-readable response text, resolved from Accept-Language or the documented browser preference. Technical codes and identifiers remain stable.
Referrer-PolicyJSON; {"enum":["strict-origin-when-cross-origin","no-referrer"]}The default referrer policy is strict-origin-when-cross-origin. Provider-login responses use no-referrer to protect login parameters.
Retry-Afterstring; {"pattern":"^[0-9]+$"}Seconds before retry. Preserve supported idempotency identifiers and respect the operation’s mutation semantics.
VarystringResponses vary by Accept-Language; browser-rendered responses can also vary by the preference cookie.
X-Content-Type-OptionsJSON; {"const":"nosniff"}The browser must use the declared content type.
X-Frame-OptionsJSON; {"const":"DENY"}The response must not be embedded in a frame.
X-Request-IDstringServer-generated request identifier. Include this when reporting an error; inbound values are not trusted.

application/problem+json

FieldType and limitsRequiredMeaning
$ProblemYes—
$.codestringYesStable machine-readable error code
$.detailstringYesShort localized explanation without internal error details
$.instancestringYesUnique relative identifier /api/v1/requests/{request_id}; not a retrievable resource
$.messagestringYesTemporarily identical to detail for existing clients
$.message_keystringYesStable translation key for changing the displayed language without another request
$.message_paramsobject; {"additionalProperties":true}YesNamed, safely rendered message parameters; never arbitrary HTML
$.request_idstring; {"pattern":"^[0-9a-f]{32}$"}YesServer-generated diagnostic identifier. It contains no login token or credential.
$.statusinteger; {"maximum":599,"minimum":400}Yes—
$.titlestringYesLocalized HTTP status title
$.typestring; {"const":"about:blank"}Yes—
json
{
  "code": "demo",
  "detail": "Demo error detail; inspect the documented code.",
  "instance": "demo",
  "message": "Demo error detail; inspect the documented code.",
  "message_key": "errors.requestFailed",
  "message_params": {},
  "request_id": "00000000000000000000000000000000",
  "status": 503,
  "title": "Demo error",
  "type": "about:blank"
}

Retries and asynchronous work

This change does not have a general retry guarantee. If the response is unclear, read the affected resource before trying again. Follow Retry-After waiting times and request new sign-in or action codes when they expire.

HTTP 202 means the background job was accepted. Use the returned job ID to check its status. Download results when the job is complete, or inspect its error or cancellation status.

Request examples

Replace demo IDs, timestamps and placeholders with your own values. For a retry, keep the same IDs, time and content. These examples do not run requests on this page.

Keep login links, codes, cookies and keys private. Do not print them in logs or share them in support requests.

shell
curl --silent --show-error --output /dev/null --write-out "%{http_code}\n" \
  --request POST \
  --header "Origin: https://metribeacon.com" \
  --header "Content-Type: application/json" \
  --data-binary '{"email":"demo@example.com"}' \
  "https://metribeacon.com/api/v1/auth/entry/email/request"
python
import json
from pathlib import Path
from urllib.request import Request, HTTPRedirectHandler, build_opener
from urllib.error import HTTPError

headers = {}
headers["Origin"] = "https://metribeacon.com"
headers["Content-Type"] = "application/json"
request = Request("https://metribeacon.com/api/v1/auth/entry/email/request", data="{\"email\":\"demo@example.com\"}".encode("utf-8"), headers=headers, method="POST")
class NoRedirect(HTTPRedirectHandler):
    def redirect_request(self, request, fp, code, message, headers, target):
        return None

opener = build_opener(NoRedirect())
try:
    with opener.open(request, timeout=10) as response:
        print(response.status)
except HTTPError as error:
    print(error.code)
    error.close()
javascript
import { readFile } from "node:fs/promises";
import { homedir } from "node:os";
import { join } from "node:path";

const headers = {};
headers["Origin"] = "https://metribeacon.com";
headers["Content-Type"] = "application/json";
const response = await fetch("https://metribeacon.com/api/v1/auth/entry/email/request", {
  method: "POST", headers, redirect: "manual",
  signal: AbortSignal.timeout(10000), body: "{\"email\":\"demo@example.com\"}",
});
console.log(response.status);
await response.body?.cancel();
go
package main

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

func main() {
  request, err := http.NewRequest("POST", "https://metribeacon.com/api/v1/auth/entry/email/request", strings.NewReader("{\"email\":\"demo@example.com\"}"))
  if err != nil { panic("request failed; credentials and response omitted") }
  request.Header.Set("Origin", "https://metribeacon.com")
  request.Header.Set("Content-Type", "application/json")
  client := &http.Client{Timeout: 10*time.Second, CheckRedirect: func(*http.Request, []*http.Request) error { return http.ErrUseLastResponse }}
  response, err := client.Do(request)
  if err != nil { panic("request failed; credentials and response omitted") }
  defer response.Body.Close()
  fmt.Println(response.StatusCode)
}
  • HTTP API, OAuth and MCP

    Find the user API endpoints, their permissions, fields, examples and response formats.

  • POST Confirm email proof in the requesting browser

    Accepts exactly one proof form: link token, or challenge_id with a six-digit code. Proof and flow are browser-bound and single-use; at most five incorrect attempts are allowed. Existing verified email accounts receive a seven-day session. New accounts proceed to consent_required; provider identities for an existing account proceed to link_confirmation_required without automatic linking.

  • DELETE Cancel the browser entry flow

    Cancels outstanding email challenges and the browser-bound entry flow, then clears its pre-authentication cookie. It does not revoke an existing application session. Requires the allowed browser origin.

  • GET Read the current browser entry step

    Reads the flow bound to __Host-mb_auth without creating an application session. Missing, expired, completed or cancelled flows return status idle. Active flows describe verification, consent or explicit identity linking.