Send type and value to GenderAPI.io V2. Compare GET query parameters with POST JSON, including country, AI modes and forceToGenderize.
POST JSON parameters
Parameter
Type
Required
Default
Description
Parametertype
Typestring
RequiredYes
Default—
DescriptionInput category: name, email or username.
Parametervalue
Typestring
RequiredYes
Default—
DescriptionRequired. 1–254 characters; nonblank, without control characters. Email values must be valid email syntax.
Parametercountry
Typestring
RequiredNo
Default—
DescriptionOptional uppercase ISO 3166-1 alpha-2 code, for example TR or US. Country-specific lookup can fall back to the global dataset.
ParameterforceToGenderize
Typeboolean
RequiredNo
Defaultfalse
DescriptionTry the dataset first, then nickname-aware AI if unresolved. Supported for name, email and username.
Parameteroptions
Typeobject
RequiredNo
Default—
DescriptionContainer for per-input AI options.
Parameteroptions.ai_mode
Typestring
RequiredNo
Defaultfallback
DescriptionAllowed values: off, fallback, always. With forceToGenderize: true, omit this field or use fallback.
Parameterid
Typestring
RequiredNo
Default—
DescriptionOptional 1–64 character identifier in POST JSON. Returned beside each batch result; unique within a batch. Accepted but not echoed for single predictions. Not supported in GET queries.
A dash (—) means no default is assigned. Omit unused optional inputs; do not send null. Response examples are illustrative, not default values. Nullable means the field can contain JSON null; an omitted field is described separately.
Optional fields should be omitted when unused; do not send null or empty strings in place of country or options. JSON booleans must be true or false, not strings. UTF-8 text is supported; names do not need to be transliterated to ASCII.
GET query parameters
Parameter
Type
Required
Default
Description
Parametertype
Typestring
RequiredNo
Defaultname
DescriptionInput category: name, email or username.
Parametervalue
Typestring
RequiredYes
Default—
DescriptionRequired. 1–254 characters; nonblank, without control characters. Email values must be valid email syntax.
Parametercountry
Typestring
RequiredNo
Default—
DescriptionOptional uppercase ISO 3166-1 alpha-2 code, for example TR or US. Country-specific lookup can fall back to the global dataset.
ParameterforceToGenderize
Typeboolean
RequiredNo
Defaultfalse
DescriptionTry the dataset first, then nickname-aware AI if unresolved. Supported for name, email and username.
Parameterai_mode
Typestring
RequiredNo
Defaultfallback
DescriptionAllowed values: off, fallback, always. With forceToGenderize: true, omit this field or use fallback.
Parameterkey
Typestring
RequiredNo
Default—
DescriptionExisting API key for GET requests. Prefer the Authorization header; missing or unknown keys use the IP trial.
GET uses type, value, country, forceToGenderize and ai_mode directly in the query string, plus optional key. Encode values with your HTTP client's URL parameter encoder; for example @ becomes %40. For GET booleans, send true or false. Unknown fields and invalid values are rejected.
Before sending the request
Send GenderAPI.io V2 prediction requests to POST https://api.genderapi.io/api/v2/gender with type and value in the JSON body. Use your existing GenderAPI.io key in Authorization: Bearer YOUR_API_KEY and Content-Type: application/json. Read the result from data and the access and billing information from meta. Every request is processed independently.
Choose your language in the code example. Set GENDERAPI_API_KEY in the process environment before running it. Missing or unrecognized keys can use the shared IP trial, so confirm meta.access.mode is api_key when integrating an account.
This example uses the shared request fields for a name lookup. Change type and value for an email or username, or set options.ai_mode and forceToGenderize as described above.
Choose your language.Set up your API key, then run the example on your server.
Every prediction request is a new billable operation, including retries. These examples do not automatically retry. Check billing status before sending another request.
Before you run: access and error handling
Run these examples on your server. Set GENDERAPI_API_KEY in the process environment to your existing API key. Confirm meta.access.mode is api_key: an unrecognized key can fall back to the IP trial.
HTTP 4xx and 5xx JSON responses preserve the error body and return a nonzero exit status. Check code, action and meta.usage.billing_status before retrying.
// Server-side Node.js. Save as example.mjs.const apiKey = process.env.GENDERAPI_API_KEY;if (!apiKey) throw new Error("Set GENDERAPI_API_KEY");const body = { "type": "name", "value": "James", "country": "US"};const response = await fetch("https://api.genderapi.io/api/v2/gender", { method: "POST", headers: { Authorization: `Bearer ${apiKey}`, "Content-Type": "application/json", }, body: JSON.stringify(body), signal: AbortSignal.timeout(30_000), redirect: "error",});const raw = await response.text();if (!(response.headers.get("content-type") ?? "").includes("json")) { throw new Error(`HTTP ${response.status}: expected JSON; request ID ${response.headers.get("x-request-id")}`);}const result = JSON.parse(raw); // Also accepts application/problem+json.if (!response.ok) { console.error(`HTTP ${response.status}`, result); process.exitCode = 1; // A retry is a new operation; inspect billing first.} else { console.log(JSON.stringify(result, null, 2)); // For batches, inspect every item: HTTP 200 may contain item errors.}
Node.js 22+; built-in fetch. Save as example.mjs and run node example.mjs. Runtime documentation
Python
import jsonimport osimport sysimport urllib.errorimport urllib.requestapi_key = os.environ.get("GENDERAPI_API_KEY")if not api_key: raise RuntimeError("Set GENDERAPI_API_KEY")body = json.loads("{\"type\":\"name\",\"value\":\"James\",\"country\":\"US\"}")class NoRedirect(urllib.request.HTTPRedirectHandler): def redirect_request(self, req, fp, code, msg, headers, newurl): return Nonerequest = urllib.request.Request( "https://api.genderapi.io/api/v2/gender", method="POST", data=json.dumps(body).encode("utf-8"), headers={ "Authorization": "Bearer " + api_key, "Content-Type": "application/json", },)opener = urllib.request.build_opener(NoRedirect())try: response = opener.open(request, timeout=30)except urllib.error.HTTPError as error: response = error # Keep the Problem Details body on non-2xx responses.with response: status = response.status raw = response.read().decode("utf-8") if "json" not in response.headers.get("Content-Type", ""): raise RuntimeError(f"HTTP {status}: expected a JSON response") result = json.loads(raw)print(json.dumps(result, indent=2), file=sys.stderr if status >= 300 else sys.stdout)if not 200 <= status < 300: sys.exit(1) # Inspect code, action and billing before retrying.# For batches, inspect every item even when HTTP status is 200.
Python 3.10+; standard library. Save as example.py and run python3 example.py. Runtime documentation
PHP 8+ with the cURL extension. Save as example.php and run php example.php. Runtime documentation
Java
import java.net.URI;import java.net.http.HttpClient;import java.net.http.HttpRequest;import java.net.http.HttpResponse;import java.nio.charset.StandardCharsets;import java.time.Duration;public class GenderApiExample { private static String requiredEnv(String name) { String value = System.getenv(name); if (value == null || value.isBlank()) throw new IllegalStateException("Set " + name); return value; } public static void main(String[] args) throws Exception { String apiKey = requiredEnv("GENDERAPI_API_KEY"); String body = "{\"type\":\"name\",\"value\":\"James\",\"country\":\"US\"}"; HttpClient client = HttpClient.newBuilder() .connectTimeout(Duration.ofSeconds(10)) .followRedirects(HttpClient.Redirect.NEVER) .build(); HttpRequest request = HttpRequest.newBuilder(URI.create("https://api.genderapi.io/api/v2/gender")) .timeout(Duration.ofSeconds(30)) .header("Authorization", "Bearer " + apiKey) .header("Content-Type", "application/json") .POST(HttpRequest.BodyPublishers.ofString(body, StandardCharsets.UTF_8)) .build(); HttpResponse<String> response = client.send(request, HttpResponse.BodyHandlers.ofString(StandardCharsets.UTF_8)); if (!response.headers().firstValue("content-type").orElse("").contains("json")) { throw new IllegalStateException("HTTP " + response.statusCode() + ": expected JSON"); } // JSON text; parse with your application's JSON library when integrating. if (response.statusCode() < 200 || response.statusCode() >= 300) { System.err.println(response.body()); // Includes Problem Details. System.exit(1); } System.out.println(response.body()); // For batches, inspect each item's data or error, including on HTTP 200. }}
Java 17+; standard HTTP client. Save as GenderApiExample.java and run java GenderApiExample.java. Runtime documentation
C# / .NET
using System;using System.Net.Http;using System.Net.Http.Headers;using System.Text;using System.Text.Json;string RequiredEnv(string name) => !string.IsNullOrWhiteSpace(Environment.GetEnvironmentVariable(name)) ? Environment.GetEnvironmentVariable(name)! : throw new InvalidOperationException($"Set {name}");var apiKey = RequiredEnv("GENDERAPI_API_KEY");using var handler = new HttpClientHandler { AllowAutoRedirect = false };using var client = new HttpClient(handler) { Timeout = TimeSpan.FromSeconds(30) };using var request = new HttpRequestMessage(HttpMethod.Post, "https://api.genderapi.io/api/v2/gender");request.Headers.Authorization = new AuthenticationHeaderValue("Bearer", apiKey);request.Content = new StringContent("{\"type\":\"name\",\"value\":\"James\",\"country\":\"US\"}", Encoding.UTF8, "application/json");using var response = await client.SendAsync(request);var raw = await response.Content.ReadAsStringAsync();if (!(response.Content.Headers.ContentType?.MediaType?.Contains("json") ?? false)) throw new InvalidOperationException($"HTTP {(int)response.StatusCode}: expected JSON");using var result = JsonDocument.Parse(raw);if (!response.IsSuccessStatusCode){ Console.Error.WriteLine(result.RootElement); // Preserve Problem Details. Environment.ExitCode = 1;}else{ Console.WriteLine(result.RootElement); // For batches, inspect every item even on HTTP 200.}
.NET 8+ console application. Use as Program.cs in a console project, then run dotnet run. Runtime documentation
Go
package mainimport ( "encoding/json" "fmt" "io" "net/http" "os" "strings" "time")func requiredEnv(name string) string { value := os.Getenv(name) if value == "" { panic("Set " + name) } return value}func run() error { apiKey := requiredEnv("GENDERAPI_API_KEY") body := "{\"type\":\"name\",\"value\":\"James\",\"country\":\"US\"}" request, err := http.NewRequest("POST", "https://api.genderapi.io/api/v2/gender", strings.NewReader(body)) if err != nil { return err } request.Header.Set("Authorization", "Bearer " + apiKey) request.Header.Set("Content-Type", "application/json") client := &http.Client{ Timeout: 30 * time.Second, CheckRedirect: func(req *http.Request, via []*http.Request) error { return http.ErrUseLastResponse }, } response, err := client.Do(request) if err != nil { return err } defer response.Body.Close() raw, err := io.ReadAll(response.Body) if err != nil { return err } if !strings.Contains(response.Header.Get("Content-Type"), "json") || !json.Valid(raw) { return fmt.Errorf("HTTP %d: expected a JSON response", response.StatusCode) } if response.StatusCode < 200 || response.StatusCode >= 300 { return fmt.Errorf("HTTP %d: %s", response.StatusCode, raw) } fmt.Println(string(raw)) // For batches, inspect every item even on HTTP 200. return nil}func main() { if err := run(); err != nil { fmt.Fprintln(os.Stderr, err) // Keep Problem Details for error handling. os.Exit(1) }}
Go 1.22+; standard library. Save as main.go and run go run main.go. Runtime documentation