anthropic.go

  1package providers
  2
  3import (
  4	"context"
  5	"encoding/base64"
  6	"encoding/json"
  7	"errors"
  8	"fmt"
  9	"io"
 10	"maps"
 11	"strings"
 12
 13	"github.com/anthropics/anthropic-sdk-go"
 14	"github.com/anthropics/anthropic-sdk-go/option"
 15	"github.com/anthropics/anthropic-sdk-go/packages/param"
 16	"github.com/charmbracelet/crush/internal/ai"
 17)
 18
 19type AnthropicProviderOptions struct {
 20	SendReasoning          *bool                            `json:"send_reasoning,omitempty"`
 21	Thinking               *AnthropicThinkingProviderOption `json:"thinking,omitempty"`
 22	DisableParallelToolUse *bool                            `json:"disable_parallel_tool_use,omitempty"`
 23}
 24
 25type AnthropicThinkingProviderOption struct {
 26	BudgetTokens int64 `json:"budget_tokens"`
 27}
 28
 29type AnthropicReasoningMetadata struct {
 30	Signature    string `json:"signature"`
 31	RedactedData string `json:"redacted_data"`
 32}
 33
 34type AnthropicCacheControlProviderOptions struct {
 35	Type string `json:"type"`
 36}
 37type AnthropicFilePartProviderOptions struct {
 38	EnableCitations bool   `json:"enable_citations"`
 39	Title           string `json:"title"`
 40	Context         string `json:"context"`
 41}
 42
 43type anthropicProviderOptions struct {
 44	baseURL string
 45	apiKey  string
 46	name    string
 47	headers map[string]string
 48	client  option.HTTPClient
 49}
 50
 51type anthropicProvider struct {
 52	options anthropicProviderOptions
 53}
 54
 55type AnthropicOption = func(*anthropicProviderOptions)
 56
 57func NewAnthropicProvider(opts ...AnthropicOption) ai.Provider {
 58	options := anthropicProviderOptions{
 59		headers: map[string]string{},
 60	}
 61	for _, o := range opts {
 62		o(&options)
 63	}
 64	if options.baseURL == "" {
 65		options.baseURL = "https://api.anthropic.com"
 66	}
 67
 68	if options.name == "" {
 69		options.name = "anthropic"
 70	}
 71
 72	return &anthropicProvider{
 73		options: options,
 74	}
 75}
 76
 77func WithAnthropicBaseURL(baseURL string) AnthropicOption {
 78	return func(o *anthropicProviderOptions) {
 79		o.baseURL = baseURL
 80	}
 81}
 82
 83func WithAnthropicAPIKey(apiKey string) AnthropicOption {
 84	return func(o *anthropicProviderOptions) {
 85		o.apiKey = apiKey
 86	}
 87}
 88
 89func WithAnthropicName(name string) AnthropicOption {
 90	return func(o *anthropicProviderOptions) {
 91		o.name = name
 92	}
 93}
 94
 95func WithAnthropicHeaders(headers map[string]string) AnthropicOption {
 96	return func(o *anthropicProviderOptions) {
 97		maps.Copy(o.headers, headers)
 98	}
 99}
100
101func WithAnthropicHTTPClient(client option.HTTPClient) AnthropicOption {
102	return func(o *anthropicProviderOptions) {
103		o.client = client
104	}
105}
106
107func (a *anthropicProvider) LanguageModel(modelID string) (ai.LanguageModel, error) {
108	anthropicClientOptions := []option.RequestOption{}
109	if a.options.apiKey != "" {
110		anthropicClientOptions = append(anthropicClientOptions, option.WithAPIKey(a.options.apiKey))
111	}
112	if a.options.baseURL != "" {
113		anthropicClientOptions = append(anthropicClientOptions, option.WithBaseURL(a.options.baseURL))
114	}
115
116	for key, value := range a.options.headers {
117		anthropicClientOptions = append(anthropicClientOptions, option.WithHeader(key, value))
118	}
119
120	if a.options.client != nil {
121		anthropicClientOptions = append(anthropicClientOptions, option.WithHTTPClient(a.options.client))
122	}
123	return anthropicLanguageModel{
124		modelID:         modelID,
125		provider:        fmt.Sprintf("%s.messages", a.options.name),
126		providerOptions: a.options,
127		client:          anthropic.NewClient(anthropicClientOptions...),
128	}, nil
129}
130
131type anthropicLanguageModel struct {
132	provider        string
133	modelID         string
134	client          anthropic.Client
135	providerOptions anthropicProviderOptions
136}
137
138// Model implements ai.LanguageModel.
139func (a anthropicLanguageModel) Model() string {
140	return a.modelID
141}
142
143// Provider implements ai.LanguageModel.
144func (a anthropicLanguageModel) Provider() string {
145	return a.provider
146}
147
148func (a anthropicLanguageModel) prepareParams(call ai.Call) (*anthropic.MessageNewParams, []ai.CallWarning, error) {
149	params := &anthropic.MessageNewParams{}
150	providerOptions := &AnthropicProviderOptions{}
151	if v, ok := call.ProviderOptions["anthropic"]; ok {
152		err := ai.ParseOptions(v, providerOptions)
153		if err != nil {
154			return nil, nil, err
155		}
156	}
157	sendReasoning := true
158	if providerOptions.SendReasoning != nil {
159		sendReasoning = *providerOptions.SendReasoning
160	}
161	systemBlocks, messages, warnings := toAnthropicPrompt(call.Prompt, sendReasoning)
162
163	if call.FrequencyPenalty != nil {
164		warnings = append(warnings, ai.CallWarning{
165			Type:    ai.CallWarningTypeUnsupportedSetting,
166			Setting: "FrequencyPenalty",
167		})
168	}
169	if call.PresencePenalty != nil {
170		warnings = append(warnings, ai.CallWarning{
171			Type:    ai.CallWarningTypeUnsupportedSetting,
172			Setting: "PresencePenalty",
173		})
174	}
175
176	params.System = systemBlocks
177	params.Messages = messages
178	params.Model = anthropic.Model(a.modelID)
179	params.MaxTokens = 4096
180
181	if call.MaxOutputTokens != nil {
182		params.MaxTokens = *call.MaxOutputTokens
183	}
184
185	if call.Temperature != nil {
186		params.Temperature = param.NewOpt(*call.Temperature)
187	}
188	if call.TopK != nil {
189		params.TopK = param.NewOpt(*call.TopK)
190	}
191	if call.TopP != nil {
192		params.TopP = param.NewOpt(*call.TopP)
193	}
194
195	isThinking := false
196	var thinkingBudget int64
197	if providerOptions.Thinking != nil {
198		isThinking = true
199		thinkingBudget = providerOptions.Thinking.BudgetTokens
200	}
201	if isThinking {
202		if thinkingBudget == 0 {
203			return nil, nil, ai.NewUnsupportedFunctionalityError("thinking requires budget", "")
204		}
205		params.Thinking = anthropic.ThinkingConfigParamOfEnabled(thinkingBudget)
206		if call.Temperature != nil {
207			params.Temperature = param.Opt[float64]{}
208			warnings = append(warnings, ai.CallWarning{
209				Type:    ai.CallWarningTypeUnsupportedSetting,
210				Setting: "temperature",
211				Details: "temperature is not supported when thinking is enabled",
212			})
213		}
214		if call.TopP != nil {
215			params.TopP = param.Opt[float64]{}
216			warnings = append(warnings, ai.CallWarning{
217				Type:    ai.CallWarningTypeUnsupportedSetting,
218				Setting: "TopP",
219				Details: "TopP is not supported when thinking is enabled",
220			})
221		}
222		if call.TopK != nil {
223			params.TopK = param.Opt[int64]{}
224			warnings = append(warnings, ai.CallWarning{
225				Type:    ai.CallWarningTypeUnsupportedSetting,
226				Setting: "TopK",
227				Details: "TopK is not supported when thinking is enabled",
228			})
229		}
230		params.MaxTokens = params.MaxTokens + thinkingBudget
231	}
232
233	if len(call.Tools) > 0 {
234		disableParallelToolUse := false
235		if providerOptions.DisableParallelToolUse != nil {
236			disableParallelToolUse = *providerOptions.DisableParallelToolUse
237		}
238		tools, toolChoice, toolWarnings := toAnthropicTools(call.Tools, call.ToolChoice, *&disableParallelToolUse)
239		params.Tools = tools
240		if toolChoice != nil {
241			params.ToolChoice = *toolChoice
242		}
243		warnings = append(warnings, toolWarnings...)
244	}
245
246	return params, warnings, nil
247}
248
249func getCacheControl(providerOptions ai.ProviderOptions) *AnthropicCacheControlProviderOptions {
250	if anthropicOptions, ok := providerOptions["anthropic"]; ok {
251		if cacheControl, ok := anthropicOptions["cache_control"]; ok {
252			if cc, ok := cacheControl.(map[string]any); ok {
253				cacheControlOption := &AnthropicCacheControlProviderOptions{}
254				err := ai.ParseOptions(cc, cacheControlOption)
255				if err != nil {
256					return cacheControlOption
257				}
258			}
259		} else if cacheControl, ok := anthropicOptions["cacheControl"]; ok {
260			if cc, ok := cacheControl.(map[string]any); ok {
261				cacheControlOption := &AnthropicCacheControlProviderOptions{}
262				err := ai.ParseOptions(cc, cacheControlOption)
263				if err != nil {
264					return cacheControlOption
265				}
266			}
267		}
268	}
269	return nil
270}
271
272func getReasoningMetadata(providerOptions ai.ProviderOptions) *AnthropicReasoningMetadata {
273	if anthropicOptions, ok := providerOptions["anthropic"]; ok {
274		reasoningMetadata := &AnthropicReasoningMetadata{}
275		err := ai.ParseOptions(anthropicOptions, reasoningMetadata)
276		if err != nil {
277			return reasoningMetadata
278		}
279	}
280	return nil
281}
282
283type messageBlock struct {
284	Role     ai.MessageRole
285	Messages []ai.Message
286}
287
288func groupIntoBlocks(prompt ai.Prompt) []*messageBlock {
289	var blocks []*messageBlock
290
291	var currentBlock *messageBlock
292
293	for _, msg := range prompt {
294		switch msg.Role {
295		case ai.MessageRoleSystem:
296			if currentBlock == nil || currentBlock.Role != ai.MessageRoleSystem {
297				currentBlock = &messageBlock{
298					Role:     ai.MessageRoleSystem,
299					Messages: []ai.Message{},
300				}
301				blocks = append(blocks, currentBlock)
302			}
303			currentBlock.Messages = append(currentBlock.Messages, msg)
304		case ai.MessageRoleUser:
305			if currentBlock == nil || currentBlock.Role != ai.MessageRoleUser {
306				currentBlock = &messageBlock{
307					Role:     ai.MessageRoleUser,
308					Messages: []ai.Message{},
309				}
310				blocks = append(blocks, currentBlock)
311			}
312			currentBlock.Messages = append(currentBlock.Messages, msg)
313		case ai.MessageRoleAssistant:
314			if currentBlock == nil || currentBlock.Role != ai.MessageRoleAssistant {
315				currentBlock = &messageBlock{
316					Role:     ai.MessageRoleAssistant,
317					Messages: []ai.Message{},
318				}
319				blocks = append(blocks, currentBlock)
320			}
321			currentBlock.Messages = append(currentBlock.Messages, msg)
322		case ai.MessageRoleTool:
323			if currentBlock == nil || currentBlock.Role != ai.MessageRoleUser {
324				currentBlock = &messageBlock{
325					Role:     ai.MessageRoleUser,
326					Messages: []ai.Message{},
327				}
328				blocks = append(blocks, currentBlock)
329			}
330			currentBlock.Messages = append(currentBlock.Messages, msg)
331		}
332	}
333	return blocks
334}
335
336func toAnthropicTools(tools []ai.Tool, toolChoice *ai.ToolChoice, disableParallelToolCalls bool) (anthropicTools []anthropic.ToolUnionParam, anthropicToolChoice *anthropic.ToolChoiceUnionParam, warnings []ai.CallWarning) {
337	for _, tool := range tools {
338
339		if tool.GetType() == ai.ToolTypeFunction {
340			ft, ok := tool.(ai.FunctionTool)
341			if !ok {
342				continue
343			}
344			required := []string{}
345			var properties any
346			if props, ok := ft.InputSchema["properties"]; ok {
347				properties = props
348			}
349			if req, ok := ft.InputSchema["required"]; ok {
350				if reqArr, ok := req.([]string); ok {
351					required = reqArr
352				}
353			}
354			cacheControl := getCacheControl(ft.ProviderOptions)
355
356			anthropicTool := anthropic.ToolParam{
357				Name:        ft.Name,
358				Description: anthropic.String(ft.Description),
359				InputSchema: anthropic.ToolInputSchemaParam{
360					Properties: properties,
361					Required:   required,
362				},
363			}
364			if cacheControl != nil {
365				anthropicTool.CacheControl = anthropic.NewCacheControlEphemeralParam()
366			}
367			anthropicTools = append(anthropicTools, anthropic.ToolUnionParam{OfTool: &anthropicTool})
368			continue
369		}
370		// TODO: handle provider tool calls
371		warnings = append(warnings, ai.CallWarning{
372			Type:    ai.CallWarningTypeUnsupportedTool,
373			Tool:    tool,
374			Message: "tool is not supported",
375		})
376	}
377	if toolChoice == nil {
378		return
379	}
380
381	switch *toolChoice {
382	case ai.ToolChoiceAuto:
383		anthropicToolChoice = &anthropic.ToolChoiceUnionParam{
384			OfAuto: &anthropic.ToolChoiceAutoParam{
385				Type:                   "auto",
386				DisableParallelToolUse: param.NewOpt(disableParallelToolCalls),
387			},
388		}
389	case ai.ToolChoiceRequired:
390		anthropicToolChoice = &anthropic.ToolChoiceUnionParam{
391			OfAny: &anthropic.ToolChoiceAnyParam{
392				Type:                   "any",
393				DisableParallelToolUse: param.NewOpt(disableParallelToolCalls),
394			},
395		}
396	default:
397		anthropicToolChoice = &anthropic.ToolChoiceUnionParam{
398			OfTool: &anthropic.ToolChoiceToolParam{
399				Type:                   "tool",
400				Name:                   string(*toolChoice),
401				DisableParallelToolUse: param.NewOpt(disableParallelToolCalls),
402			},
403		}
404	}
405	return
406}
407
408func toAnthropicPrompt(prompt ai.Prompt, sendReasoningData bool) ([]anthropic.TextBlockParam, []anthropic.MessageParam, []ai.CallWarning) {
409	var systemBlocks []anthropic.TextBlockParam
410	var messages []anthropic.MessageParam
411	var warnings []ai.CallWarning
412
413	blocks := groupIntoBlocks(prompt)
414	finishedSystemBlock := false
415	for _, block := range blocks {
416		switch block.Role {
417		case ai.MessageRoleSystem:
418			if finishedSystemBlock {
419				// skip multiple system messages that are separated by user/assistant messages
420				// TODO: see if we need to send error here?
421				continue
422			}
423			finishedSystemBlock = true
424			for _, msg := range block.Messages {
425				for _, part := range msg.Content {
426					cacheControl := getCacheControl(part.Options())
427					text, ok := ai.AsMessagePart[ai.TextPart](part)
428					if !ok {
429						continue
430					}
431					textBlock := anthropic.TextBlockParam{
432						Text: text.Text,
433					}
434					if cacheControl != nil {
435						textBlock.CacheControl = anthropic.NewCacheControlEphemeralParam()
436					}
437					systemBlocks = append(systemBlocks, textBlock)
438				}
439			}
440
441		case ai.MessageRoleUser:
442			var anthropicContent []anthropic.ContentBlockParamUnion
443			for _, msg := range block.Messages {
444				if msg.Role == ai.MessageRoleUser {
445					for i, part := range msg.Content {
446						isLastPart := i == len(msg.Content)-1
447						cacheControl := getCacheControl(part.Options())
448						if cacheControl == nil && isLastPart {
449							cacheControl = getCacheControl(msg.ProviderOptions)
450						}
451						switch part.GetType() {
452						case ai.ContentTypeText:
453							text, ok := ai.AsMessagePart[ai.TextPart](part)
454							if !ok {
455								continue
456							}
457							textBlock := &anthropic.TextBlockParam{
458								Text: text.Text,
459							}
460							if cacheControl != nil {
461								textBlock.CacheControl = anthropic.NewCacheControlEphemeralParam()
462							}
463							anthropicContent = append(anthropicContent, anthropic.ContentBlockParamUnion{
464								OfText: textBlock,
465							})
466						case ai.ContentTypeFile:
467							file, ok := ai.AsMessagePart[ai.FilePart](part)
468							if !ok {
469								continue
470							}
471							// TODO: handle other file types
472							if !strings.HasPrefix(file.MediaType, "image/") {
473								continue
474							}
475
476							base64Encoded := base64.StdEncoding.EncodeToString(file.Data)
477							imageBlock := anthropic.NewImageBlockBase64(file.MediaType, base64Encoded)
478							if cacheControl != nil {
479								imageBlock.OfImage.CacheControl = anthropic.NewCacheControlEphemeralParam()
480							}
481							anthropicContent = append(anthropicContent, imageBlock)
482						}
483					}
484				} else if msg.Role == ai.MessageRoleTool {
485					for i, part := range msg.Content {
486						isLastPart := i == len(msg.Content)-1
487						cacheControl := getCacheControl(part.Options())
488						if cacheControl == nil && isLastPart {
489							cacheControl = getCacheControl(msg.ProviderOptions)
490						}
491						result, ok := ai.AsMessagePart[ai.ToolResultPart](part)
492						if !ok {
493							continue
494						}
495						toolResultBlock := anthropic.ToolResultBlockParam{
496							ToolUseID: result.ToolCallID,
497						}
498						switch result.Output.GetType() {
499						case ai.ToolResultContentTypeText:
500							content, ok := ai.AsToolResultOutputType[ai.ToolResultOutputContentText](result.Output)
501							if !ok {
502								continue
503							}
504							toolResultBlock.Content = []anthropic.ToolResultBlockParamContentUnion{
505								{
506									OfText: &anthropic.TextBlockParam{
507										Text: content.Text,
508									},
509								},
510							}
511						case ai.ToolResultContentTypeMedia:
512							content, ok := ai.AsToolResultOutputType[ai.ToolResultOutputContentMedia](result.Output)
513							if !ok {
514								continue
515							}
516							toolResultBlock.Content = []anthropic.ToolResultBlockParamContentUnion{
517								{
518									OfImage: anthropic.NewImageBlockBase64(content.MediaType, content.Data).OfImage,
519								},
520							}
521						case ai.ToolResultContentTypeError:
522							content, ok := ai.AsToolResultOutputType[ai.ToolResultOutputContentError](result.Output)
523							if !ok {
524								continue
525							}
526							toolResultBlock.Content = []anthropic.ToolResultBlockParamContentUnion{
527								{
528									OfText: &anthropic.TextBlockParam{
529										Text: content.Error.Error(),
530									},
531								},
532							}
533							toolResultBlock.IsError = param.NewOpt(true)
534						}
535						if cacheControl != nil {
536							toolResultBlock.CacheControl = anthropic.NewCacheControlEphemeralParam()
537						}
538						anthropicContent = append(anthropicContent, anthropic.ContentBlockParamUnion{
539							OfToolResult: &toolResultBlock,
540						})
541					}
542				}
543			}
544			messages = append(messages, anthropic.NewUserMessage(anthropicContent...))
545		case ai.MessageRoleAssistant:
546			var anthropicContent []anthropic.ContentBlockParamUnion
547			for _, msg := range block.Messages {
548				for i, part := range msg.Content {
549					isLastPart := i == len(msg.Content)-1
550					cacheControl := getCacheControl(part.Options())
551					if cacheControl == nil && isLastPart {
552						cacheControl = getCacheControl(msg.ProviderOptions)
553					}
554					switch part.GetType() {
555					case ai.ContentTypeText:
556						text, ok := ai.AsMessagePart[ai.TextPart](part)
557						if !ok {
558							continue
559						}
560						textBlock := &anthropic.TextBlockParam{
561							Text: text.Text,
562						}
563						if cacheControl != nil {
564							textBlock.CacheControl = anthropic.NewCacheControlEphemeralParam()
565						}
566						anthropicContent = append(anthropicContent, anthropic.ContentBlockParamUnion{
567							OfText: textBlock,
568						})
569					case ai.ContentTypeReasoning:
570						reasoning, ok := ai.AsMessagePart[ai.ReasoningPart](part)
571						if !ok {
572							continue
573						}
574						if !sendReasoningData {
575							warnings = append(warnings, ai.CallWarning{
576								Type:    "other",
577								Message: "sending reasoning content is disabled for this model",
578							})
579							continue
580						}
581						reasoningMetadata := getReasoningMetadata(part.Options())
582						if reasoningMetadata == nil {
583							warnings = append(warnings, ai.CallWarning{
584								Type:    "other",
585								Message: "unsupported reasoning metadata",
586							})
587							continue
588						}
589
590						if reasoningMetadata.Signature != "" {
591							anthropicContent = append(anthropicContent, anthropic.NewThinkingBlock(reasoningMetadata.Signature, reasoning.Text))
592						} else if reasoningMetadata.RedactedData != "" {
593							anthropicContent = append(anthropicContent, anthropic.NewRedactedThinkingBlock(reasoningMetadata.RedactedData))
594						} else {
595							warnings = append(warnings, ai.CallWarning{
596								Type:    "other",
597								Message: "unsupported reasoning metadata",
598							})
599							continue
600						}
601					case ai.ContentTypeToolCall:
602						toolCall, ok := ai.AsMessagePart[ai.ToolCallPart](part)
603						if !ok {
604							continue
605						}
606						if toolCall.ProviderExecuted {
607							// TODO: implement provider executed call
608							continue
609						}
610
611						var inputMap map[string]any
612						err := json.Unmarshal([]byte(toolCall.Input), &inputMap)
613						if err != nil {
614							continue
615						}
616						toolUseBlock := anthropic.NewToolUseBlock(toolCall.ToolCallID, inputMap, toolCall.ToolName)
617						if cacheControl != nil {
618							toolUseBlock.OfToolUse.CacheControl = anthropic.NewCacheControlEphemeralParam()
619						}
620						anthropicContent = append(anthropicContent, toolUseBlock)
621					case ai.ContentTypeToolResult:
622						// TODO: implement provider executed tool result
623					}
624
625				}
626			}
627			messages = append(messages, anthropic.NewAssistantMessage(anthropicContent...))
628		}
629	}
630	return systemBlocks, messages, warnings
631}
632
633func (o anthropicLanguageModel) handleError(err error) error {
634	var apiErr *anthropic.Error
635	if errors.As(err, &apiErr) {
636		requestDump := apiErr.DumpRequest(true)
637		responseDump := apiErr.DumpResponse(true)
638		headers := map[string]string{}
639		for k, h := range apiErr.Response.Header {
640			v := h[len(h)-1]
641			headers[strings.ToLower(k)] = v
642		}
643		return ai.NewAPICallError(
644			apiErr.Error(),
645			apiErr.Request.URL.String(),
646			string(requestDump),
647			apiErr.StatusCode,
648			headers,
649			string(responseDump),
650			apiErr,
651			false,
652		)
653	}
654	return err
655}
656
657func mapAnthropicFinishReason(finishReason string) ai.FinishReason {
658	switch finishReason {
659	case "end", "stop_sequence":
660		return ai.FinishReasonStop
661	case "max_tokens":
662		return ai.FinishReasonLength
663	case "tool_use":
664		return ai.FinishReasonToolCalls
665	default:
666		return ai.FinishReasonUnknown
667	}
668}
669
670// Generate implements ai.LanguageModel.
671func (a anthropicLanguageModel) Generate(ctx context.Context, call ai.Call) (*ai.Response, error) {
672	params, warnings, err := a.prepareParams(call)
673	if err != nil {
674		return nil, err
675	}
676	response, err := a.client.Messages.New(ctx, *params)
677	if err != nil {
678		return nil, a.handleError(err)
679	}
680
681	var content []ai.Content
682	for _, block := range response.Content {
683		switch block.Type {
684		case "text":
685			text, ok := block.AsAny().(anthropic.TextBlock)
686			if !ok {
687				continue
688			}
689			content = append(content, ai.TextContent{
690				Text: text.Text,
691			})
692		case "thinking":
693			reasoning, ok := block.AsAny().(anthropic.ThinkingBlock)
694			if !ok {
695				continue
696			}
697			content = append(content, ai.ReasoningContent{
698				Text: reasoning.Thinking,
699				ProviderMetadata: map[string]map[string]any{
700					"anthropic": {
701						"signature": reasoning.Signature,
702					},
703				},
704			})
705		case "redacted_thinking":
706			reasoning, ok := block.AsAny().(anthropic.RedactedThinkingBlock)
707			if !ok {
708				continue
709			}
710			content = append(content, ai.ReasoningContent{
711				Text: "",
712				ProviderMetadata: map[string]map[string]any{
713					"anthropic": {
714						"redacted_data": reasoning.Data,
715					},
716				},
717			})
718		case "tool_use":
719			toolUse, ok := block.AsAny().(anthropic.ToolUseBlock)
720			if !ok {
721				continue
722			}
723			content = append(content, ai.ToolCallContent{
724				ToolCallID:       toolUse.ID,
725				ToolName:         toolUse.Name,
726				Input:            string(toolUse.Input),
727				ProviderExecuted: false,
728			})
729		}
730	}
731
732	return &ai.Response{
733		Content: content,
734		Usage: ai.Usage{
735			InputTokens:         response.Usage.InputTokens,
736			OutputTokens:        response.Usage.OutputTokens,
737			TotalTokens:         response.Usage.InputTokens + response.Usage.OutputTokens,
738			CacheCreationTokens: response.Usage.CacheCreationInputTokens,
739			CacheReadTokens:     response.Usage.CacheReadInputTokens,
740		},
741		FinishReason: mapAnthropicFinishReason(string(response.StopReason)),
742		ProviderMetadata: ai.ProviderMetadata{
743			"anthropic": make(map[string]any),
744		},
745		Warnings: warnings,
746	}, nil
747}
748
749// Stream implements ai.LanguageModel.
750func (a anthropicLanguageModel) Stream(ctx context.Context, call ai.Call) (ai.StreamResponse, error) {
751	params, warnings, err := a.prepareParams(call)
752	if err != nil {
753		return nil, err
754	}
755
756	stream := a.client.Messages.NewStreaming(ctx, *params)
757	acc := anthropic.Message{}
758	return func(yield func(ai.StreamPart) bool) {
759		if len(warnings) > 0 {
760			if !yield(ai.StreamPart{
761				Type:     ai.StreamPartTypeWarnings,
762				Warnings: warnings,
763			}) {
764				return
765			}
766		}
767
768		for stream.Next() {
769			chunk := stream.Current()
770			acc.Accumulate(chunk)
771			switch chunk.Type {
772			case "content_block_start":
773				contentBlockType := chunk.ContentBlock.Type
774				switch contentBlockType {
775				case "text":
776					if !yield(ai.StreamPart{
777						Type: ai.StreamPartTypeTextStart,
778						ID:   fmt.Sprintf("%d", chunk.Index),
779					}) {
780						return
781					}
782				case "thinking":
783					if !yield(ai.StreamPart{
784						Type: ai.StreamPartTypeReasoningStart,
785						ID:   fmt.Sprintf("%d", chunk.Index),
786					}) {
787						return
788					}
789				case "redacted_thinking":
790					if !yield(ai.StreamPart{
791						Type: ai.StreamPartTypeReasoningStart,
792						ID:   fmt.Sprintf("%d", chunk.Index),
793						ProviderMetadata: ai.ProviderMetadata{
794							"anthropic": {
795								"redacted_data": chunk.ContentBlock.Data,
796							},
797						},
798					}) {
799						return
800					}
801				case "tool_use":
802					if !yield(ai.StreamPart{
803						Type:          ai.StreamPartTypeToolInputStart,
804						ID:            chunk.ContentBlock.ID,
805						ToolCallName:  chunk.ContentBlock.Name,
806						ToolCallInput: "",
807					}) {
808						return
809					}
810				}
811			case "content_block_stop":
812				if len(acc.Content)-1 < int(chunk.Index) {
813					continue
814				}
815				contentBlock := acc.Content[int(chunk.Index)]
816				switch contentBlock.Type {
817				case "text":
818					if !yield(ai.StreamPart{
819						Type: ai.StreamPartTypeTextEnd,
820						ID:   fmt.Sprintf("%d", chunk.Index),
821					}) {
822						return
823					}
824				case "thinking":
825					if !yield(ai.StreamPart{
826						Type: ai.StreamPartTypeReasoningEnd,
827						ID:   fmt.Sprintf("%d", chunk.Index),
828					}) {
829						return
830					}
831				case "tool_use":
832					if !yield(ai.StreamPart{
833						Type: ai.StreamPartTypeToolInputEnd,
834						ID:   contentBlock.ID,
835					}) {
836						return
837					}
838					if !yield(ai.StreamPart{
839						Type:          ai.StreamPartTypeToolCall,
840						ID:            contentBlock.ID,
841						ToolCallName:  contentBlock.Name,
842						ToolCallInput: string(contentBlock.Input),
843					}) {
844						return
845					}
846
847				}
848			case "content_block_delta":
849				switch chunk.Delta.Type {
850				case "text_delta":
851					if !yield(ai.StreamPart{
852						Type:  ai.StreamPartTypeTextDelta,
853						ID:    fmt.Sprintf("%d", chunk.Index),
854						Delta: chunk.Delta.Text,
855					}) {
856						return
857					}
858				case "thinking_delta":
859					if !yield(ai.StreamPart{
860						Type:  ai.StreamPartTypeReasoningDelta,
861						ID:    fmt.Sprintf("%d", chunk.Index),
862						Delta: chunk.Delta.Text,
863					}) {
864						return
865					}
866				case "signature_delta":
867					if !yield(ai.StreamPart{
868						Type: ai.StreamPartTypeReasoningDelta,
869						ID:   fmt.Sprintf("%d", chunk.Index),
870						ProviderMetadata: ai.ProviderMetadata{
871							"anthropic": {
872								"signature": chunk.Delta.Signature,
873							},
874						},
875					}) {
876						return
877					}
878				case "input_json_delta":
879					if len(acc.Content)-1 < int(chunk.Index) {
880						continue
881					}
882					contentBlock := acc.Content[int(chunk.Index)]
883					if !yield(ai.StreamPart{
884						Type:          ai.StreamPartTypeToolInputDelta,
885						ID:            contentBlock.ID,
886						ToolCallInput: chunk.Delta.PartialJSON,
887					}) {
888						return
889					}
890
891				}
892			case "message_stop":
893			}
894		}
895
896		err := stream.Err()
897		if err == nil || errors.Is(err, io.EOF) {
898			yield(ai.StreamPart{
899				Type:         ai.StreamPartTypeFinish,
900				ID:           acc.ID,
901				FinishReason: mapAnthropicFinishReason(string(acc.StopReason)),
902				Usage: ai.Usage{
903					InputTokens:         acc.Usage.InputTokens,
904					OutputTokens:        acc.Usage.OutputTokens,
905					TotalTokens:         acc.Usage.InputTokens + acc.Usage.OutputTokens,
906					CacheCreationTokens: acc.Usage.CacheCreationInputTokens,
907					CacheReadTokens:     acc.Usage.CacheReadInputTokens,
908				},
909				ProviderMetadata: ai.ProviderMetadata{
910					"anthropic": make(map[string]any),
911				},
912			})
913			return
914		} else {
915			yield(ai.StreamPart{
916				Type:  ai.StreamPartTypeError,
917				Error: a.handleError(err),
918			})
919			return
920		}
921	}, nil
922}