Claude Platform Docs

Create a Text Completion

Completion completions().create(CompletionCreateParamsparams, RequestOptionsrequestOptions = RequestOptions.none())
POST/v1/complete

[Legacy] Create a Text Completion.

The Text Completions API is a legacy API. We recommend using the Messages API going forward.

Future models and features will not be compatible with Text Completions. See our migration guide for guidance in migrating from Text Completions to Messages.

Parameters
CompletionCreateParams params
Optional<List<AnthropicBeta>> betas

Optional header to specify the beta version(s) you want to use.

MESSAGE_BATCHES_2024_09_24("message-batches-2024-09-24")
PROMPT_CACHING_2024_07_31("prompt-caching-2024-07-31")
COMPUTER_USE_2024_10_22("computer-use-2024-10-22")
COMPUTER_USE_2025_01_24("computer-use-2025-01-24")
PDFS_2024_09_25("pdfs-2024-09-25")
TOKEN_COUNTING_2024_11_01("token-counting-2024-11-01")
TOKEN_EFFICIENT_TOOLS_2025_02_19("token-efficient-tools-2025-02-19")
OUTPUT_128K_2025_02_19("output-128k-2025-02-19")
FILES_API_2025_04_14("files-api-2025-04-14")
MCP_CLIENT_2025_04_04("mcp-client-2025-04-04")
MCP_CLIENT_2025_11_20("mcp-client-2025-11-20")
DEV_FULL_THINKING_2025_05_14("dev-full-thinking-2025-05-14")
INTERLEAVED_THINKING_2025_05_14("interleaved-thinking-2025-05-14")
CODE_EXECUTION_2025_05_22("code-execution-2025-05-22")
EXTENDED_CACHE_TTL_2025_04_11("extended-cache-ttl-2025-04-11")
CONTEXT_1M_2025_08_07("context-1m-2025-08-07")
CONTEXT_MANAGEMENT_2025_06_27("context-management-2025-06-27")
MODEL_CONTEXT_WINDOW_EXCEEDED_2025_08_26("model-context-window-exceeded-2025-08-26")
SKILLS_2025_10_02("skills-2025-10-02")
FAST_MODE_2026_02_01("fast-mode-2026-02-01")
OUTPUT_300K_2026_03_24("output-300k-2026-03-24")
USER_PROFILES_2026_03_24("user-profiles-2026-03-24")
USER_PROFILES_2026_08_18("user-profiles-2026-08-18")
ADVISOR_TOOL_2026_03_01("advisor-tool-2026-03-01")
MANAGED_AGENTS_2026_04_01("managed-agents-2026-04-01")
CACHE_DIAGNOSIS_2026_04_07("cache-diagnosis-2026-04-07")
DREAMING_2026_04_21("dreaming-2026-04-21")
THINKING_TOKEN_COUNT_2026_05_13("thinking-token-count-2026-05-13")
SERVER_SIDE_FALLBACK_2026_06_01("server-side-fallback-2026-06-01")
SERVER_SIDE_FALLBACK_2026_07_01("server-side-fallback-2026-07-01")
FALLBACK_CREDIT_2026_06_01("fallback-credit-2026-06-01")
FALLBACK_CREDIT_2026_07_01("fallback-credit-2026-07-01")
AGENT_MEMORY_2026_07_22("agent-memory-2026-07-22")
MID_CONVERSATION_TOOL_CHANGES_2026_07_01("mid-conversation-tool-changes-2026-07-01")
COMPACT_2026_01_12("compact-2026-01-12")
COMPUTER_USE_2025_11_24("computer-use-2025-11-24")
MCP_TUNNELS_2026_06_22("mcp-tunnels-2026-06-22")
STRUCTURED_OUTPUTS_2025_11_13("structured-outputs-2025-11-13")
TASK_BUDGETS_2026_03_13("task-budgets-2026-03-13")
THINKING_DISPLAY_UPDATES_2026_08_18("thinking-display-updates-2026-08-18")
CE_USER_MANAGEMENT_2026_07_13("ce-user-management-2026-07-13")
long maxTokensToSample

The maximum number of tokens to generate before stopping.

Note that our models may stop before reaching this maximum. This parameter only specifies the absolute maximum number of tokens to generate.

minimum1
Model model

The model that will complete your prompt.

See models for additional details and options.

String prompt

The prompt that you want Claude to complete.

For proper response generation you will need to format your prompt using alternating `

Human:and

Assistant:` conversational turns. For example:

"

Human: {userQuestion}

Assistant:"

See prompt validation and our guide to prompt design for more details.

minLength1
Optional<Metadata> metadata

An object describing metadata about the request.

Optional<List<String>> stopSequences

Sequences that will cause the model to stop generating.

Our models stop on `"

Human:"`, and may include additional built-in stop sequences in the future. By providing the stop_sequences parameter, you may include additional strings that will cause the model to stop generating.

Optional<Double> temperatureDeprecated

Amount of randomness injected into the response.

Deprecated. Models released after Claude Opus 4.6 do not support setting temperature. A value of 1.0 of will be accepted for backwards compatibility, all other values will be rejected with a 400 error.

Defaults to 1.0. Ranges from 0.0 to 1.0. Use temperature closer to 0.0 for analytical / multiple choice, and closer to 1.0 for creative and generative tasks.

Note that even with temperature of 0.0, the results will not be fully deterministic.

maximum1
minimum0
Optional<Long> topKDeprecated

Only sample from the top K options for each subsequent token.

Deprecated. Models released after Claude Opus 4.6 do not accept top_k; any value will be rejected with a 400 error.

Used to remove "long tail" low probability responses. Learn more technical details here.

Recommended for advanced use cases only.

minimum0
Optional<Double> topPDeprecated

Use nucleus sampling.

Deprecated. Models released after Claude Opus 4.6 do not support setting top_p. A value >= 0.99 will be accepted for backwards compatibility, all other values will be rejected with a 400 error.

In nucleus sampling, we compute the cumulative distribution over all the options for each subsequent token in decreasing probability order and cut it off once it reaches a particular probability specified by top_p.

Recommended for advanced use cases only.

maximum1
minimum0
Returns
class Completion:
class Completion:

Create a Text Completion

package com.anthropic.example;

import com.anthropic.client.AnthropicClient;
import com.anthropic.client.okhttp.AnthropicOkHttpClient;
import com.anthropic.models.completions.Completion;
import com.anthropic.models.completions.CompletionCreateParams;
import com.anthropic.models.messages.Model;

public final class Main {
    private Main() {}

    public static void main(String[] args) {
        AnthropicClient client = AnthropicOkHttpClient.fromEnv();

        CompletionCreateParams params = CompletionCreateParams.builder()
            .maxTokensToSample(256L)
            .model(Model.CLAUDE_SONNET_5)
            .prompt("\n\nHuman: Hello, world!\n\nAssistant:")
            .build();
        Completion completion = client.completions().create(params);
    }
}
{
  "id": "compl_018CKm6gsux7P8yMcwZbeCPw",
  "completion": " Hello! My name is Claude.",
  "model": "claude-2.1",
  "stop_reason": "stop_sequence",
  "type": "completion"
}
Returns Examples
{
  "id": "compl_018CKm6gsux7P8yMcwZbeCPw",
  "completion": " Hello! My name is Claude.",
  "model": "claude-2.1",
  "stop_reason": "stop_sequence",
  "type": "completion"
}