PHP SDK

The Anthropic PHP library provides convenient access to the Anthropic REST API from any PHP 8.1.0+ application.

The PHP SDK is currently in beta. APIs may change between versions.

For API feature documentation with code examples, see the API reference. This page covers PHP-specific SDK features and configuration.

Installation

composer require "anthropic-ai/sdk"

Requirements

PHP 8.1.0 or higher.

Usage

This library uses named parameters to specify optional arguments. Parameters with a default value must be set by name.

<?php

use Anthropic\Client;

$client = new Client(
  apiKey: getenv("ANTHROPIC_API_KEY") ?: "my-anthropic-api-key"
);

$message = $client->messages->create(
  maxTokens: 1024,
  messages: [['role' => 'user', 'content' => 'Hello, Claude']],
  model: 'claude-opus-4-6',
);

var_dump($message->content);

Value objects

It is recommended to use the static with constructor Base64ImageSource::with(data: "U3RhaW5sZXNzIHJvY2tz", ...) and named parameters to initialize value objects.

However, builders are also provided (new Base64ImageSource)->withData("U3RhaW5sZXNzIHJvY2tz").

Streaming

The SDK provides support for streaming responses using Server-Sent Events (SSE).

<?php

use Anthropic\Client;

$client = new Client(
  apiKey: getenv("ANTHROPIC_API_KEY") ?: "my-anthropic-api-key"
);

$stream = $client->messages->createStream(
  maxTokens: 1024,
  messages: [['role' => 'user', 'content' => 'Hello, Claude']],
  model: 'claude-opus-4-6',
);

foreach ($stream as $message) {
  var_dump($message);
}

Error handling

When the library is unable to connect to the API, or if the API returns a non-success status code (i.e., 4xx or 5xx response), a subclass of Anthropic\Core\Exceptions\APIException is thrown:

<?php
// ...
use Anthropic\Core\Exceptions\APIConnectionException;
use Anthropic\Core\Exceptions\APIStatusException;
use Anthropic\Core\Exceptions\RateLimitException;

// ...
try {
  $message = $client->messages->create(
    maxTokens: 1024,
    messages: [['role' => 'user', 'content' => 'Hello, Claude']],
    model: 'claude-opus-4-6',
  );
} catch (APIConnectionException $e) {
  echo "The server could not be reached", PHP_EOL;
  var_dump($e->getPrevious());
} catch (RateLimitException $_) {
  echo "A 429 status code was received; we should back off a bit.", PHP_EOL;
} catch (APIStatusException $e) {
  echo "Another non-200-range status code was received", PHP_EOL;
  echo $e->getMessage();
}

Error codes are as follows:

Cause	Error Type
HTTP 400	`BadRequestException`
HTTP 401	`AuthenticationException`
HTTP 403	`PermissionDeniedException`
HTTP 404	`NotFoundException`
HTTP 409	`ConflictException`
HTTP 422	`UnprocessableEntityException`
HTTP 429	`RateLimitException`
HTTP >= 500	`InternalServerException`

Retries

Certain errors are automatically retried 2 times by default, with a short exponential backoff.

Connection errors (for example, due to a network connectivity problem), 408 Request Timeout, 409 Conflict, 429 Rate Limit, >=500 Internal errors, and timeouts are all retried by default.

You can use the maxRetries option to configure or disable this:

<?php

use Anthropic\Client;
use Anthropic\RequestOptions;

// Configure the default for all requests:
$client = new Client(requestOptions: RequestOptions::with(maxRetries: 0));

// Or, configure per-request:
$result = $client->messages->create(
  maxTokens: 1024,
  messages: [['role' => 'user', 'content' => 'Hello, Claude']],
  model: 'claude-opus-4-6',
  requestOptions: RequestOptions::with(maxRetries: 5),
);

Pagination

List methods in the Claude API are paginated.

This library provides auto-paginating iterators with each list response, so you do not have to request successive pages manually:

<?php

use Anthropic\Client;

$client = new Client(
  apiKey: getenv("ANTHROPIC_API_KEY") ?: "my-anthropic-api-key"
);

$page = $client->beta->messages->batches->list(limit: 20);

var_dump($page);

// fetch items from the current page
foreach ($page->getItems() as $item) {
  var_dump($item->id);
}
// make additional network requests to fetch items from all pages, including and after the current page
foreach ($page->pagingEachItem() as $item) {
  var_dump($item->id);
}

Advanced usage

Undocumented properties

You can send undocumented parameters to any endpoint, and read undocumented response properties, like so:

The extra* parameters of the same name override the documented parameters.

<?php
// ...
use Anthropic\RequestOptions;

// ...
$message = $client->messages->create(
  maxTokens: 1024,
  messages: [['role' => 'user', 'content' => 'Hello, Claude']],
  model: 'claude-opus-4-6',
  requestOptions: RequestOptions::with(
    extraQueryParams: ['my_query_parameter' => 'value'],
    extraBodyParams: ['my_body_parameter' => 'value'],
    extraHeaders: ['my-header' => 'value'],
  ),
);

Undocumented request params

If you want to explicitly send an extra param, you can do so with the extraQueryParams, extraBodyParams, and extraHeaders options under RequestOptions::with() when making a request, as seen in the example above.

Undocumented endpoints

To make requests to undocumented endpoints while retaining the benefit of auth, retries, and so on, you can make requests using client->request, like so:

<?php
// ...
$response = $client->request(
  method: "post",
  path: '/undocumented/endpoint',
  query: ['dog' => 'woof'],
  headers: ['useful-header' => 'interesting-value'],
  body: ['hello' => 'world']
);

Semantic versioning

This package follows SemVer conventions. As the library is in initial development and has a major version of 0, APIs may change at any time.

This package considers improvements to the (non-runtime) PHPDoc type definitions to be non-breaking changes.

Installation

Requirements

Usage

Value objects

Streaming

Error handling

Retries

Pagination

Advanced usage

Undocumented properties

Undocumented request params

Undocumented endpoints

Semantic versioning

Additional resources