Anthropic

Configuration

'anthropic' => [
    'api_key' => env('ANTHROPIC_API_KEY', ''),
    'version' => env('ANTHROPIC_API_VERSION', '2023-06-01'),
    'default_thinking_budget' => env('ANTHROPIC_DEFAULT_THINKING_BUDGET', 1024),
    // Include beta strings as a comma separated list.
    'anthropic_beta' => env('ANTHROPIC_BETA', null),
]

Prompt caching

Anthropic's prompt caching feature allows you to drastically reduce latency and your API bill when repeatedly re-using blocks of content within five minutes of each other.

We support Anthropic prompt caching on:

• System Messages (text only)
• User Messages (Text, Image and PDF (pdf only))
• Assistant Messages (text only)
• Tools

The API for enabling prompt caching is the same for all, enabled via the withProviderOptions() method. Where a UserMessage contains both text and an image or document, both will be cached.

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;
use Prism\Prism\Tool;
use Prism\Prism\ValueObjects\Messages\UserMessage;
use Prism\Prism\ValueObjects\Messages\SystemMessage;

Prism::text()
    ->using(Provider::Anthropic, 'claude-3-5-sonnet-20241022')
    ->withMessages([
        (new SystemMessage('I am a long re-usable system message.'))
            ->withProviderOptions(['cacheType' => 'ephemeral']),

        (new UserMessage('I am a long re-usable user message.'))
            ->withProviderOptions(['cacheType' => 'ephemeral'])
    ])
    ->withTools([
        Tool::as('cache me')
            ->withProviderOptions(['cacheType' => 'ephemeral'])
    ])
    ->asText();

If you prefer, you can use the AnthropicCacheType Enum like so:

use Prism\Prism\Enums\Provider;
use Prism\Prism\Providers\Anthropic\Enums\AnthropicCacheType;
use Prism\Prism\ValueObjects\Messages\UserMessage;
use Prism\Prism\ValueObjects\Messages\Support\Document;

(new UserMessage('I am a long re-usable user message.'))->withProviderOptions(['cacheType' => AnthropicCacheType::ephemeral])

Note that you must use the withMessages() method in order to enable prompt caching, rather than withPrompt() or withSystemPrompt().

Tool result caching

In addition to caching prompts and tool definitions, Prism supports caching tool results. This is particularly useful when making multiple tool calls where results might be referenced repeatedly.

To enable tool result caching, use the tool_result_cache_type provider option on your request:

use Prism\Prism\Prism;

$response = Prism::text()
    ->using('anthropic', 'claude-3-5-sonnet-20241022')
    ->withMaxSteps(30)
    ->withTools([new WeatherTool()])
    ->withProviderOptions([
        'tool_result_cache_type' => 'ephemeral'
    ])
    ->withPrompt('Check the weather in New York, London, Tokyo, Paris, and Sydney')
    ->asText();

When multiple tool results are returned, Prism automatically applies caching to only the last result, which caches all preceding results as well. This avoids Anthropic's 4-cache-breakpoint limitation.

Please ensure you read Anthropic's prompt caching documentation, which covers some important information on e.g. minimum cacheable tokens and message order consistency.

Extended thinking

Claude Sonnet 3.7 supports an optional extended thinking mode, where it will reason before returning its answer. Please ensure your consider Anthropic's own extended thinking documentation before using extended thinking with caching and/or tools, as there are some important limitations and behaviours to be aware of.

Enabling extended thinking and setting budget

Prism supports thinking mode for text and structured with the same API:

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;

Prism::text()
    ->using('anthropic', 'claude-3-7-sonnet-latest')
    ->withPrompt('What is the meaning of life, the universe and everything in popular fiction?')
    // enable thinking
    ->withProviderOptions(['thinking' => ['enabled' => true]]) 
    ->asText();

By default Prism will set the thinking budget to the value set in config, or where that isn't set, the minimum allowed (1024).

You can overide the config (or its default) using withProviderOptions:

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;

Prism::text()
    ->using('anthropic', 'claude-3-7-sonnet-latest')
    ->withPrompt('What is the meaning of life, the universe and everything in popular fiction?')
    // Enable thinking and set a budget
    ->withProviderOptions([
        'thinking' => [
            'enabled' => true, 
            'budgetTokens' => 2048
        ]
    ]);

Note that thinking tokens count towards output tokens, so you will be billed for them and your token budget must be less than the max tokens you have set for the request.

If you expect a long response, you should ensure there's enough tokens left for the response - i.e. does (maxTokens - thinkingBudget) leave a sufficient remainder.

Inspecting the thinking block

Anthropic returns the thinking block with its response.

You can access it via the additionalContent property on either the Response or the relevant step.

On the Response (easiest if not using tools):

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;

Prism::text()
    ->using('anthropic', 'claude-3-7-sonnet-latest')
    ->withPrompt('What is the meaning of life, the universe and everything in popular fiction?')
    ->withProviderOptions(['thinking' => ['enabled' => true']]) 
    ->asText();

$response->additionalContent['thinking'];

On the Step (necessary if using tools, as Anthropic returns the thinking block on the ToolCall step):

$tools = [...];

$response = Prism::text()
    ->using('anthropic', 'claude-3-7-sonnet-latest')
    ->withTools($tools)
    ->withMaxSteps(3)
    ->withPrompt('What time is the tigers game today and should I wear a coat?')
    ->withProviderOptions(['thinking' => ['enabled' => true]])
    ->asText();

$response->steps->first()->additionalContent->thinking;

Extended output mode

Claude Sonnet 3.7 also brings extended output mode which increase the output limit to 128k tokens.

This feature is currently in beta, so you will need to enable to by adding output-128k-2025-02-19 to your Anthropic anthropic_beta config (see Configuration above).

Documents

Anthropic supports PDF, text and markdown documents. Note that Anthropic uses vision to process PDFs under the hood, and consequently there are some limitations detailed in their feature documentation.

See the Documents on how to get started using them.

Anthropic also supports "custom content documents", separately documented below, which are primarily for use with citations.

Custom content documents

Custom content documents are primarily for use with citations (see below), if you need citations to reference your own chunking strategy.

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;
use Prism\Prism\ValueObjects\Messages\UserMessage;
use Prism\Prism\ValueObjects\Messages\Support\Document;

Prism::text()
    ->using(Provider::Anthropic, 'claude-3-5-sonnet-20241022')
    ->withMessages([
        new UserMessage(
            content: "Is the grass green and the sky blue?",
            additionalContent: [
                Document::fromChunks(["The grass is green.", "Flamingos are pink.", "The sky is blue."])
            ]
        )
    ])
    ->asText();

Citations

Prism supports Anthropic's citations feature for both text and structured.

Please note however that due to Anthropic not supporting "native" structured output, and Prism's workaround for this, the output can be unreliable. You should therefore ensure you implement proper error handling for the scenario where Anthropic does not return a valid decodable schema.

Code execution

To enable code execution, you will first need to enable the beta feature.

Either in prism/config.php:

        'anthropic' => [
            ...
            'anthropic_beta' => 'code-execution-2025-05-22',
        ],

Or in your env file (assuming config/prism.php reflects the default prism setup):

ANTHROPIC_BETA="code-execution-2025-05-22"

You may then use code execution as follows:

use Prism\Prism\Prism;
use Prism\Prism\ValueObjects\ProviderTool;

Prism::text()
    ->using('anthropic', 'claude-3-5-haiku-latest')
    ->withPrompt('Solve the equation 3x + 10 = 14.')
    ->withProviderTools([new ProviderTool(type: 'code_execution_20250522', name: 'code_execution')])
    ->asText();

Enabling citations

Anthropic require citations to be enabled on all documents in a request. To enable them, using the withProviderOptions() method when building your request:

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;
use Prism\Prism\ValueObjects\Messages\UserMessage;
use Prism\Prism\ValueObjects\Messages\Support\Document;

$response = Prism::text()
    ->using(Provider::Anthropic, 'claude-3-5-sonnet-20241022')
    ->withMessages([
        new UserMessage(
            content: "Is the grass green and the sky blue?",
            additionalContent: [
                Document::fromChunks(
                    chunks: ["The grass is green.", "Flamingos are pink.", "The sky is blue."],
                    title: 'The colours of nature',
                    context: 'The go-to textbook on the colours found in nature!'
                )
            ]
        )
    ])
    ->withProviderOptions(['citations' => true])
    ->asText();

Accessing citations

You can access the chunked output with its citations via the additionalContent property on a response, which returns an array of Providers\Anthropic\ValueObjects\MessagePartWithCitationss.

As a rough worked example, let's assume you want to implement footnotes. You'll need to loop through those chunks and (1) re-construct the message with links to the footnotes; and (2) build an array of footnotes to loop through in your frontend.

use Prism\Prism\Providers\Anthropic\ValueObjects\MessagePartWithCitations;
use Prism\Prism\Providers\Anthropic\ValueObjects\Citation;

$messageChunks = $response->additionalContent['messagePartsWithCitations'];

$text = '';
$footnotes = [];

$footnoteId = 1;

/** @var MessagePartWithCitations $messageChunk  */
foreach ($messageChunks as $messageChunk) {
    $text .= $messageChunk->text;
    
    /** @var Citation $citation */
    foreach ($messageChunk->citations as $citation) {
        $footnotes[] = [
            'id' => $footnoteId,
            'document_title' => $citation->documentTitle,
            'reference_start' => $citation->startIndex,
            'reference_end' => $citation->endIndex
        ];
    
        $text .= '<sup><a href="#footnote-'.$footnoteId.'">'.$footnoteId.'</a></sup>';
    
        $footnoteId++;
    }
}

Note that when using streaming, Anthropic does not stream citations in the same way. Instead, of building the context as above, yield text to the browser in the usual way and pair text up with the relevant footnote using the citationIndex on the text chunk's additionalContent parameter.

Considerations

Message Order

• Message order matters. Anthropic is strict about the message order being:

1. UserMessage
2. AssistantMessage
3. UserMessage

Structured Output

While Anthropic models don't have native JSON mode or structured output like some providers, Prism implements two approaches for structured output:

Default JSON Mode (Prompt-based)

• We automatically append instructions to your prompt that guide the model to output valid JSON matching your schema
• If the response isn't valid JSON, Prism will raise a PrismException
• This method can sometimes struggle with complex JSON containing quotes, especially in non-English languages

Tool Calling Mode (Recommended)

For more reliable structured output, especially when dealing with complex content or non-English text that may contain quotes, you can enable tool calling mode:

use Prism\Prism\Enums\Provider;
use Prism\Prism\Prism;
use Prism\Prism\Schema\ObjectSchema;
use Prism\Prism\Schema\StringSchema;

$response = Prism::structured()
    ->withSchema(new ObjectSchema(
        'weather_report',
        'Weather forecast with recommendations',
        [
            new StringSchema('forecast', 'The weather forecast'),
            new StringSchema('recommendation', 'Clothing recommendation')
        ],
        ['forecast', 'recommendation']
    ))
    ->using(Provider::Anthropic, 'claude-3-5-sonnet-latest')
    ->withPrompt('What\'s the weather like and what should I wear?')
    ->withProviderOptions(['use_tool_calling' => true])
    ->asStructured();

Benefits of tool calling mode:

• More reliable JSON parsing, especially with quotes and special characters
• Better handling of non-English content (Chinese, Japanese, etc.)
• Reduced risk of malformed JSON responses
• Compatible with thinking mode

Limitations:

• Cannot be used with citations (citations are not supported in tool calling mode)
• Slightly more complex under the hood but identical API usage

Limitations

Messages

Most providers' API include system messages in the messages array with a "system" role. Anthropic does not support the system role, and instead has a "system" property, separate from messages.

Therefore, for Anthropic we:

• Filter all SystemMessages out, omitting them from messages.
• Always submit the prompt defined with ->withSystemPrompt() at the top of the system prompts array.
• Move all SystemMessages to the system prompts array in the order they were declared.

Images

Does not support Image::fromURL