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prwhelanelasticmachine
prwhelan
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[ML] Stream Anthropic Completion (#114321)
Enable chat completion streaming responses for Anthropic's server sent events. Co-authored-by: Elastic Machine <[email protected]>
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-13
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12 files changed

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‎docs/changelog/114321.yaml‎

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pr: 114321
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summary: Stream Anthropic Completion
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area: Machine Learning
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type: enhancement
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issues: []

‎x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/external/anthropic/AnthropicResponseHandler.java‎

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@@ -9,14 +9,20 @@
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import org.apache.logging.log4j.Logger;
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import org.elasticsearch.common.Strings;
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import org.elasticsearch.inference.InferenceServiceResults;
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import org.elasticsearch.xpack.core.inference.results.StreamingChatCompletionResults;
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import org.elasticsearch.xpack.inference.external.http.HttpResult;
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import org.elasticsearch.xpack.inference.external.http.retry.BaseResponseHandler;
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import org.elasticsearch.xpack.inference.external.http.retry.ResponseParser;
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import org.elasticsearch.xpack.inference.external.http.retry.RetryException;
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import org.elasticsearch.xpack.inference.external.request.Request;
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import org.elasticsearch.xpack.inference.external.response.ErrorMessageResponseEntity;
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import org.elasticsearch.xpack.inference.external.response.streaming.ServerSentEventParser;
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import org.elasticsearch.xpack.inference.external.response.streaming.ServerSentEventProcessor;
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import org.elasticsearch.xpack.inference.logging.ThrottlerManager;
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import java.util.concurrent.Flow;
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import static org.elasticsearch.xpack.inference.external.http.HttpUtils.checkForEmptyBody;
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import static org.elasticsearch.xpack.inference.external.http.retry.ResponseHandlerUtils.getFirstHeaderOrUnknown;
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@@ -41,8 +47,11 @@ public class AnthropicResponseHandler extends BaseResponseHandler {
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static final String SERVER_BUSY = "Received an Anthropic server is temporarily overloaded status code";
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public AnthropicResponseHandler(String requestType, ResponseParser parseFunction) {
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private final boolean canHandleStreamingResponses;
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public AnthropicResponseHandler(String requestType, ResponseParser parseFunction, boolean canHandleStreamingResponses) {
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super(requestType, parseFunction, ErrorMessageResponseEntity::fromResponse);
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this.canHandleStreamingResponses = canHandleStreamingResponses;
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}
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@Override
@@ -52,6 +61,20 @@ public void validateResponse(ThrottlerManager throttlerManager, Logger logger, R
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checkForEmptyBody(throttlerManager, logger, request, result);
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}
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@Override
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public boolean canHandleStreamingResponses() {
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return canHandleStreamingResponses;
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}
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@Override
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public InferenceServiceResults parseResult(Request request, Flow.Publisher<HttpResult> flow) {
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var sseProcessor = new ServerSentEventProcessor(new ServerSentEventParser());
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var anthropicProcessor = new AnthropicStreamingProcessor();
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sseProcessor.subscribe(anthropicProcessor);
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flow.subscribe(sseProcessor);
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return new StreamingChatCompletionResults(anthropicProcessor);
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}
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/**
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* Validates the status code throws an RetryException if not in the range [200, 300).
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*

‎x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/external/anthropic/AnthropicStreamingProcessor.java‎

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/*
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* Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
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* or more contributor license agreements. Licensed under the Elastic License
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* 2.0; you may not use this file except in compliance with the Elastic License
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* 2.0.
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*/
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package org.elasticsearch.xpack.inference.external.anthropic;
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import org.apache.logging.log4j.LogManager;
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import org.apache.logging.log4j.Logger;
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import org.elasticsearch.ElasticsearchStatusException;
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import org.elasticsearch.rest.RestStatus;
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import org.elasticsearch.xcontent.XContentFactory;
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import org.elasticsearch.xcontent.XContentParser;
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import org.elasticsearch.xcontent.XContentParserConfiguration;
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import org.elasticsearch.xcontent.XContentType;
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import org.elasticsearch.xpack.core.inference.results.StreamingChatCompletionResults;
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import org.elasticsearch.xpack.inference.common.DelegatingProcessor;
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import org.elasticsearch.xpack.inference.external.response.streaming.ServerSentEvent;
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import org.elasticsearch.xpack.inference.external.response.streaming.ServerSentEventField;
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import java.io.IOException;
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import java.util.ArrayDeque;
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import java.util.Deque;
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import java.util.Optional;
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import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
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import static org.elasticsearch.xpack.inference.external.response.XContentUtils.moveToFirstToken;
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import static org.elasticsearch.xpack.inference.external.response.XContentUtils.positionParserAtTokenAfterField;
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public class AnthropicStreamingProcessor extends DelegatingProcessor<Deque<ServerSentEvent>, StreamingChatCompletionResults.Results> {
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private static final Logger log = LogManager.getLogger(AnthropicStreamingProcessor.class);
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private static final String FAILED_TO_FIND_FIELD_TEMPLATE = "Failed to find required field [%s] in Anthropic chat completions response";
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@Override
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protected void next(Deque<ServerSentEvent> item) throws Exception {
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if (item.isEmpty()) {
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upstream().request(1);
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return;
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}
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var results = new ArrayDeque<StreamingChatCompletionResults.Result>(item.size());
44+
for (var event : item) {
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if (event.name() == ServerSentEventField.DATA && event.hasValue()) {
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try (var parser = parser(event.value())) {
47+
var eventType = eventType(parser);
48+
switch (eventType) {
49+
case "error" -> {
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onError(parseError(parser));
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return;
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}
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case "content_block_start" -> {
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parseStartBlock(parser).ifPresent(results::offer);
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}
56+
case "content_block_delta" -> {
57+
parseMessage(parser).ifPresent(results::offer);
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}
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case "message_start", "message_stop", "message_delta", "content_block_stop", "ping" -> {
60+
log.debug("Skipping event type [{}] for line [{}].", eventType, item);
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}
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default -> {
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// "handle unknown events gracefully" https://docs.anthropic.com/en/api/messages-streaming#other-events
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// we'll ignore unknown events
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log.debug("Unknown event type [{}] for line [{}].", eventType, item);
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}
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}
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} catch (Exception e) {
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log.warn("Failed to parse line {}", event);
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throw e;
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}
72+
}
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}
74+
75+
if (results.isEmpty()) {
76+
upstream().request(1);
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} else {
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downstream().onNext(new StreamingChatCompletionResults.Results(results));
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}
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}
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private Throwable parseError(XContentParser parser) throws IOException {
83+
positionParserAtTokenAfterField(parser, "error", FAILED_TO_FIND_FIELD_TEMPLATE);
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var type = parseString(parser, "type");
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var message = parseString(parser, "message");
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var statusCode = switch (type) {
87+
case "invalid_request_error" -> RestStatus.BAD_REQUEST;
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case "authentication_error" -> RestStatus.UNAUTHORIZED;
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case "permission_error" -> RestStatus.FORBIDDEN;
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case "not_found_error" -> RestStatus.NOT_FOUND;
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case "request_too_large" -> RestStatus.REQUEST_ENTITY_TOO_LARGE;
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case "rate_limit_error" -> RestStatus.TOO_MANY_REQUESTS;
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default -> RestStatus.INTERNAL_SERVER_ERROR;
94+
};
95+
return new ElasticsearchStatusException(message, statusCode);
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}
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private Optional<StreamingChatCompletionResults.Result> parseStartBlock(XContentParser parser) throws IOException {
99+
positionParserAtTokenAfterField(parser, "content_block", FAILED_TO_FIND_FIELD_TEMPLATE);
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var text = parseString(parser, "text");
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return text.isBlank() ? Optional.empty() : Optional.of(new StreamingChatCompletionResults.Result(text));
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}
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private Optional<StreamingChatCompletionResults.Result> parseMessage(XContentParser parser) throws IOException {
105+
positionParserAtTokenAfterField(parser, "delta", FAILED_TO_FIND_FIELD_TEMPLATE);
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var text = parseString(parser, "text");
107+
return text.isBlank() ? Optional.empty() : Optional.of(new StreamingChatCompletionResults.Result(text));
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}
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private static XContentParser parser(String line) throws IOException {
111+
return XContentFactory.xContent(XContentType.JSON).createParser(XContentParserConfiguration.EMPTY, line);
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}
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private static String eventType(XContentParser parser) throws IOException {
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moveToFirstToken(parser);
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ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.currentToken(), parser);
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return parseString(parser, "type");
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}
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private static String parseString(XContentParser parser, String fieldName) throws IOException {
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positionParserAtTokenAfterField(parser, fieldName, FAILED_TO_FIND_FIELD_TEMPLATE);
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ensureExpectedToken(XContentParser.Token.VALUE_STRING, parser.currentToken(), parser);
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return parser.text();
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}
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}

‎x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/external/http/sender/AnthropicCompletionRequestManager.java‎

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@@ -19,7 +19,6 @@
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import org.elasticsearch.xpack.inference.external.response.anthropic.AnthropicChatCompletionResponseEntity;
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import org.elasticsearch.xpack.inference.services.anthropic.completion.AnthropicChatCompletionModel;
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22-
import java.util.List;
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import java.util.Objects;
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import java.util.function.Supplier;
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@@ -47,13 +46,15 @@ public void execute(
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Supplier<Boolean> hasRequestCompletedFunction,
4847
ActionListener<InferenceServiceResults> listener
4948
) {
50-
List<String> docsInput = DocumentsOnlyInput.of(inferenceInputs).getInputs();
51-
AnthropicChatCompletionRequest request = new AnthropicChatCompletionRequest(docsInput, model);
49+
var docsOnly = DocumentsOnlyInput.of(inferenceInputs);
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var docsInput = docsOnly.getInputs();
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var stream = docsOnly.stream();
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AnthropicChatCompletionRequest request = new AnthropicChatCompletionRequest(docsInput, model, stream);
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execute(new ExecutableInferenceRequest(requestSender, logger, request, HANDLER, hasRequestCompletedFunction, listener));
5455
}
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5657
private static ResponseHandler createCompletionHandler() {
57-
return new AnthropicResponseHandler("anthropic completions", AnthropicChatCompletionResponseEntity::fromResponse);
58+
return new AnthropicResponseHandler("anthropic completions", AnthropicChatCompletionResponseEntity::fromResponse, true);
5859
}
5960
}

‎x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/external/request/anthropic/AnthropicChatCompletionRequest.java‎

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@@ -29,19 +29,21 @@ public class AnthropicChatCompletionRequest implements Request {
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private final AnthropicAccount account;
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private final List<String> input;
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private final AnthropicChatCompletionModel model;
32+
private final boolean stream;
3233

33-
public AnthropicChatCompletionRequest(List<String> input, AnthropicChatCompletionModel model) {
34+
public AnthropicChatCompletionRequest(List<String> input, AnthropicChatCompletionModel model, boolean stream) {
3435
this.account = AnthropicAccount.of(model);
3536
this.input = Objects.requireNonNull(input);
3637
this.model = Objects.requireNonNull(model);
38+
this.stream = stream;
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}
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3941
@Override
4042
public HttpRequest createHttpRequest() {
4143
HttpPost httpPost = new HttpPost(account.uri());
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4345
ByteArrayEntity byteEntity = new ByteArrayEntity(
44-
Strings.toString(new AnthropicChatCompletionRequestEntity(input, model.getServiceSettings(), model.getTaskSettings()))
46+
Strings.toString(new AnthropicChatCompletionRequestEntity(input, model.getServiceSettings(), model.getTaskSettings(), stream))
4547
.getBytes(StandardCharsets.UTF_8)
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);
4749
httpPost.setEntity(byteEntity);
@@ -75,4 +77,9 @@ public String getInferenceEntityId() {
7577
return model.getInferenceEntityId();
7678
}
7779

80+
@Override
81+
public boolean isStreaming() {
82+
return stream;
83+
}
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7885
}

‎x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/external/request/anthropic/AnthropicChatCompletionRequestEntity.java‎

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private static final String TEMPERATURE_FIELD = "temperature";
2929
private static final String TOP_P_FIELD = "top_p";
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private static final String TOP_K_FIELD = "top_k";
31+
private static final String STREAM = "stream";
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3233
private final List<String> messages;
3334
private final AnthropicChatCompletionServiceSettings serviceSettings;
3435
private final AnthropicChatCompletionTaskSettings taskSettings;
36+
private final boolean stream;
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3638
public AnthropicChatCompletionRequestEntity(
3739
List<String> messages,
3840
AnthropicChatCompletionServiceSettings serviceSettings,
39-
AnthropicChatCompletionTaskSettings taskSettings
41+
AnthropicChatCompletionTaskSettings taskSettings,
42+
boolean stream
4043
) {
4144
this.messages = Objects.requireNonNull(messages);
4245
this.serviceSettings = Objects.requireNonNull(serviceSettings);
4346
this.taskSettings = Objects.requireNonNull(taskSettings);
47+
this.stream = stream;
4448
}
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4650
@Override
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7781
builder.field(TOP_K_FIELD, taskSettings.topK());
7882
}
7983

84+
if (stream) {
85+
builder.field(STREAM, true);
86+
}
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8088
builder.endObject();
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8290
return builder;

‎x-pack/plugin/inference/src/main/java/org/elasticsearch/xpack/inference/services/anthropic/AnthropicService.java‎

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3434
import java.util.List;
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import java.util.Map;
36+
import java.util.Set;
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3738
import static org.elasticsearch.xpack.inference.services.ServiceUtils.createInvalidModelException;
3839
import static org.elasticsearch.xpack.inference.services.ServiceUtils.parsePersistedConfigErrorMsg;
@@ -199,4 +200,9 @@ protected void doChunkedInfer(
199200
public TransportVersion getMinimalSupportedVersion() {
200201
return TransportVersions.ML_ANTHROPIC_INTEGRATION_ADDED;
201202
}
203+
204+
@Override
205+
public Set<TaskType> supportedStreamingTasks() {
206+
return COMPLETION_ONLY;
207+
}
202208
}

‎x-pack/plugin/inference/src/test/java/org/elasticsearch/xpack/inference/external/anthropic/AnthropicResponseHandlerTests.java‎

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@@ -160,7 +160,7 @@ private static void callCheckForFailureStatusCode(int statusCode, String inferen
160160
var mockRequest = mock(Request.class);
161161
when(mockRequest.getInferenceEntityId()).thenReturn(inferenceEntityId);
162162
var httpResult = new HttpResult(httpResponse, new byte[] {});
163-
var handler = new AnthropicResponseHandler("", (request, result) -> null);
163+
var handler = new AnthropicResponseHandler("", (request, result) -> null, false);
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165165
handler.checkForFailureStatusCode(mockRequest, httpResult);
166166
}

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