anthropic.go

  1package provider
  2
  3import (
  4	"context"
  5	"encoding/json"
  6	"errors"
  7	"fmt"
  8	"io"
  9	"strings"
 10	"time"
 11
 12	"github.com/anthropics/anthropic-sdk-go"
 13	"github.com/anthropics/anthropic-sdk-go/bedrock"
 14	"github.com/anthropics/anthropic-sdk-go/option"
 15	"github.com/kujtimiihoxha/opencode/internal/config"
 16	"github.com/kujtimiihoxha/opencode/internal/llm/tools"
 17	"github.com/kujtimiihoxha/opencode/internal/logging"
 18	"github.com/kujtimiihoxha/opencode/internal/message"
 19)
 20
 21type anthropicOptions struct {
 22	useBedrock   bool
 23	disableCache bool
 24	shouldThink  func(userMessage string) bool
 25}
 26
 27type AnthropicOption func(*anthropicOptions)
 28
 29type anthropicClient struct {
 30	providerOptions providerClientOptions
 31	options         anthropicOptions
 32	client          anthropic.Client
 33}
 34
 35type AnthropicClient ProviderClient
 36
 37func newAnthropicClient(opts providerClientOptions) AnthropicClient {
 38	anthropicOpts := anthropicOptions{}
 39	for _, o := range opts.anthropicOptions {
 40		o(&anthropicOpts)
 41	}
 42
 43	anthropicClientOptions := []option.RequestOption{}
 44	if opts.apiKey != "" {
 45		anthropicClientOptions = append(anthropicClientOptions, option.WithAPIKey(opts.apiKey))
 46	}
 47	if anthropicOpts.useBedrock {
 48		anthropicClientOptions = append(anthropicClientOptions, bedrock.WithLoadDefaultConfig(context.Background()))
 49	}
 50
 51	client := anthropic.NewClient(anthropicClientOptions...)
 52	return &anthropicClient{
 53		providerOptions: opts,
 54		options:         anthropicOpts,
 55		client:          client,
 56	}
 57}
 58
 59func (a *anthropicClient) convertMessages(messages []message.Message) (anthropicMessages []anthropic.MessageParam) {
 60	cachedBlocks := 0
 61	for _, msg := range messages {
 62		switch msg.Role {
 63		case message.User:
 64			content := anthropic.NewTextBlock(msg.Content().String())
 65			if cachedBlocks < 2 && !a.options.disableCache {
 66				content.OfRequestTextBlock.CacheControl = anthropic.CacheControlEphemeralParam{
 67					Type: "ephemeral",
 68				}
 69				cachedBlocks++
 70			}
 71			anthropicMessages = append(anthropicMessages, anthropic.NewUserMessage(content))
 72
 73		case message.Assistant:
 74			blocks := []anthropic.ContentBlockParamUnion{}
 75			if msg.Content().String() != "" {
 76				content := anthropic.NewTextBlock(msg.Content().String())
 77				if cachedBlocks < 2 && !a.options.disableCache {
 78					content.OfRequestTextBlock.CacheControl = anthropic.CacheControlEphemeralParam{
 79						Type: "ephemeral",
 80					}
 81					cachedBlocks++
 82				}
 83				blocks = append(blocks, content)
 84			}
 85
 86			for _, toolCall := range msg.ToolCalls() {
 87				var inputMap map[string]any
 88				err := json.Unmarshal([]byte(toolCall.Input), &inputMap)
 89				if err != nil {
 90					continue
 91				}
 92				blocks = append(blocks, anthropic.ContentBlockParamOfRequestToolUseBlock(toolCall.ID, inputMap, toolCall.Name))
 93			}
 94
 95			if len(blocks) == 0 {
 96				logging.Warn("There is a message without content, investigate, this should not happen")
 97				continue
 98			}
 99			anthropicMessages = append(anthropicMessages, anthropic.NewAssistantMessage(blocks...))
100
101		case message.Tool:
102			results := make([]anthropic.ContentBlockParamUnion, len(msg.ToolResults()))
103			for i, toolResult := range msg.ToolResults() {
104				results[i] = anthropic.NewToolResultBlock(toolResult.ToolCallID, toolResult.Content, toolResult.IsError)
105			}
106			anthropicMessages = append(anthropicMessages, anthropic.NewUserMessage(results...))
107		}
108	}
109	return
110}
111
112func (a *anthropicClient) convertTools(tools []tools.BaseTool) []anthropic.ToolUnionParam {
113	anthropicTools := make([]anthropic.ToolUnionParam, len(tools))
114
115	for i, tool := range tools {
116		info := tool.Info()
117		toolParam := anthropic.ToolParam{
118			Name:        info.Name,
119			Description: anthropic.String(info.Description),
120			InputSchema: anthropic.ToolInputSchemaParam{
121				Properties: info.Parameters,
122				// TODO: figure out how we can tell claude the required fields?
123			},
124		}
125
126		if i == len(tools)-1 && !a.options.disableCache {
127			toolParam.CacheControl = anthropic.CacheControlEphemeralParam{
128				Type: "ephemeral",
129			}
130		}
131
132		anthropicTools[i] = anthropic.ToolUnionParam{OfTool: &toolParam}
133	}
134
135	return anthropicTools
136}
137
138func (a *anthropicClient) finishReason(reason string) message.FinishReason {
139	switch reason {
140	case "end_turn":
141		return message.FinishReasonEndTurn
142	case "max_tokens":
143		return message.FinishReasonMaxTokens
144	case "tool_use":
145		return message.FinishReasonToolUse
146	case "stop_sequence":
147		return message.FinishReasonEndTurn
148	default:
149		return message.FinishReasonUnknown
150	}
151}
152
153func (a *anthropicClient) preparedMessages(messages []anthropic.MessageParam, tools []anthropic.ToolUnionParam) anthropic.MessageNewParams {
154	var thinkingParam anthropic.ThinkingConfigParamUnion
155	lastMessage := messages[len(messages)-1]
156	isUser := lastMessage.Role == anthropic.MessageParamRoleUser
157	messageContent := ""
158	temperature := anthropic.Float(0)
159	if isUser {
160		for _, m := range lastMessage.Content {
161			if m.OfRequestTextBlock != nil && m.OfRequestTextBlock.Text != "" {
162				messageContent = m.OfRequestTextBlock.Text
163			}
164		}
165		if messageContent != "" && a.options.shouldThink != nil && a.options.shouldThink(messageContent) {
166			thinkingParam = anthropic.ThinkingConfigParamUnion{
167				OfThinkingConfigEnabled: &anthropic.ThinkingConfigEnabledParam{
168					BudgetTokens: int64(float64(a.providerOptions.maxTokens) * 0.8),
169					Type:         "enabled",
170				},
171			}
172			temperature = anthropic.Float(1)
173		}
174	}
175
176	return anthropic.MessageNewParams{
177		Model:       anthropic.Model(a.providerOptions.model.APIModel),
178		MaxTokens:   a.providerOptions.maxTokens,
179		Temperature: temperature,
180		Messages:    messages,
181		Tools:       tools,
182		Thinking:    thinkingParam,
183		System: []anthropic.TextBlockParam{
184			{
185				Text: a.providerOptions.systemMessage,
186				CacheControl: anthropic.CacheControlEphemeralParam{
187					Type: "ephemeral",
188				},
189			},
190		},
191	}
192}
193
194func (a *anthropicClient) send(ctx context.Context, messages []message.Message, tools []tools.BaseTool) (resposne *ProviderResponse, err error) {
195	preparedMessages := a.preparedMessages(a.convertMessages(messages), a.convertTools(tools))
196	cfg := config.Get()
197	if cfg.Debug {
198		// jsonData, _ := json.Marshal(preparedMessages)
199		// logging.Debug("Prepared messages", "messages", string(jsonData))
200	}
201	attempts := 0
202	for {
203		attempts++
204		anthropicResponse, err := a.client.Messages.New(
205			ctx,
206			preparedMessages,
207		)
208		// If there is an error we are going to see if we can retry the call
209		if err != nil {
210			retry, after, retryErr := a.shouldRetry(attempts, err)
211			if retryErr != nil {
212				return nil, retryErr
213			}
214			if retry {
215				logging.WarnPersist("Retrying due to rate limit... attempt %d of %d", logging.PersistTimeArg, time.Millisecond*time.Duration(after+100))
216				select {
217				case <-ctx.Done():
218					return nil, ctx.Err()
219				case <-time.After(time.Duration(after) * time.Millisecond):
220					continue
221				}
222			}
223			return nil, retryErr
224		}
225
226		content := ""
227		for _, block := range anthropicResponse.Content {
228			if text, ok := block.AsAny().(anthropic.TextBlock); ok {
229				content += text.Text
230			}
231		}
232
233		return &ProviderResponse{
234			Content:   content,
235			ToolCalls: a.toolCalls(*anthropicResponse),
236			Usage:     a.usage(*anthropicResponse),
237		}, nil
238	}
239}
240
241func (a *anthropicClient) stream(ctx context.Context, messages []message.Message, tools []tools.BaseTool) <-chan ProviderEvent {
242	preparedMessages := a.preparedMessages(a.convertMessages(messages), a.convertTools(tools))
243	cfg := config.Get()
244	if cfg.Debug {
245		// jsonData, _ := json.Marshal(preparedMessages)
246		// logging.Debug("Prepared messages", "messages", string(jsonData))
247	}
248	attempts := 0
249	eventChan := make(chan ProviderEvent)
250	go func() {
251		for {
252			attempts++
253			anthropicStream := a.client.Messages.NewStreaming(
254				ctx,
255				preparedMessages,
256			)
257			accumulatedMessage := anthropic.Message{}
258
259			currentToolCallID := ""
260			for anthropicStream.Next() {
261				event := anthropicStream.Current()
262				err := accumulatedMessage.Accumulate(event)
263				if err != nil {
264					eventChan <- ProviderEvent{Type: EventError, Error: err}
265					continue
266				}
267
268				switch event := event.AsAny().(type) {
269				case anthropic.ContentBlockStartEvent:
270					if event.ContentBlock.Type == "text" {
271						eventChan <- ProviderEvent{Type: EventContentStart}
272					} else if event.ContentBlock.Type == "tool_use" {
273						currentToolCallID = event.ContentBlock.ID
274						eventChan <- ProviderEvent{
275							Type: EventToolUseStart,
276							ToolCall: &message.ToolCall{
277								ID:       event.ContentBlock.ID,
278								Name:     event.ContentBlock.Name,
279								Finished: false,
280							},
281						}
282					}
283
284				case anthropic.ContentBlockDeltaEvent:
285					if event.Delta.Type == "thinking_delta" && event.Delta.Thinking != "" {
286						eventChan <- ProviderEvent{
287							Type:     EventThinkingDelta,
288							Thinking: event.Delta.Thinking,
289						}
290					} else if event.Delta.Type == "text_delta" && event.Delta.Text != "" {
291						eventChan <- ProviderEvent{
292							Type:    EventContentDelta,
293							Content: event.Delta.Text,
294						}
295					} else if event.Delta.Type == "input_json_delta" {
296						if currentToolCallID != "" {
297							eventChan <- ProviderEvent{
298								Type: EventToolUseDelta,
299								ToolCall: &message.ToolCall{
300									ID:       currentToolCallID,
301									Finished: false,
302									Input:    event.Delta.JSON.PartialJSON.Raw(),
303								},
304							}
305						}
306					}
307				case anthropic.ContentBlockStopEvent:
308					if currentToolCallID != "" {
309						eventChan <- ProviderEvent{
310							Type: EventToolUseStop,
311							ToolCall: &message.ToolCall{
312								ID: currentToolCallID,
313							},
314						}
315						currentToolCallID = ""
316					} else {
317						eventChan <- ProviderEvent{Type: EventContentStop}
318					}
319
320				case anthropic.MessageStopEvent:
321					content := ""
322					for _, block := range accumulatedMessage.Content {
323						if text, ok := block.AsAny().(anthropic.TextBlock); ok {
324							content += text.Text
325						}
326					}
327
328					eventChan <- ProviderEvent{
329						Type: EventComplete,
330						Response: &ProviderResponse{
331							Content:      content,
332							ToolCalls:    a.toolCalls(accumulatedMessage),
333							Usage:        a.usage(accumulatedMessage),
334							FinishReason: a.finishReason(string(accumulatedMessage.StopReason)),
335						},
336					}
337				}
338			}
339
340			err := anthropicStream.Err()
341			if err == nil || errors.Is(err, io.EOF) {
342				close(eventChan)
343				return
344			}
345			// If there is an error we are going to see if we can retry the call
346			retry, after, retryErr := a.shouldRetry(attempts, err)
347			if retryErr != nil {
348				eventChan <- ProviderEvent{Type: EventError, Error: retryErr}
349				close(eventChan)
350				return
351			}
352			if retry {
353				logging.WarnPersist("Retrying due to rate limit... attempt %d of %d", logging.PersistTimeArg, time.Millisecond*time.Duration(after+100))
354				select {
355				case <-ctx.Done():
356					// context cancelled
357					if ctx.Err() != nil {
358						eventChan <- ProviderEvent{Type: EventError, Error: ctx.Err()}
359					}
360					close(eventChan)
361					return
362				case <-time.After(time.Duration(after) * time.Millisecond):
363					continue
364				}
365			}
366			if ctx.Err() != nil {
367				eventChan <- ProviderEvent{Type: EventError, Error: ctx.Err()}
368			}
369
370			close(eventChan)
371			return
372		}
373	}()
374	return eventChan
375}
376
377func (a *anthropicClient) shouldRetry(attempts int, err error) (bool, int64, error) {
378	var apierr *anthropic.Error
379	if !errors.As(err, &apierr) {
380		return false, 0, err
381	}
382
383	if apierr.StatusCode != 429 && apierr.StatusCode != 529 {
384		return false, 0, err
385	}
386
387	if attempts > maxRetries {
388		return false, 0, fmt.Errorf("maximum retry attempts reached for rate limit: %d retries", maxRetries)
389	}
390
391	retryMs := 0
392	retryAfterValues := apierr.Response.Header.Values("Retry-After")
393
394	backoffMs := 2000 * (1 << (attempts - 1))
395	jitterMs := int(float64(backoffMs) * 0.2)
396	retryMs = backoffMs + jitterMs
397	if len(retryAfterValues) > 0 {
398		if _, err := fmt.Sscanf(retryAfterValues[0], "%d", &retryMs); err == nil {
399			retryMs = retryMs * 1000
400		}
401	}
402	return true, int64(retryMs), nil
403}
404
405func (a *anthropicClient) toolCalls(msg anthropic.Message) []message.ToolCall {
406	var toolCalls []message.ToolCall
407
408	for _, block := range msg.Content {
409		switch variant := block.AsAny().(type) {
410		case anthropic.ToolUseBlock:
411			toolCall := message.ToolCall{
412				ID:       variant.ID,
413				Name:     variant.Name,
414				Input:    string(variant.Input),
415				Type:     string(variant.Type),
416				Finished: true,
417			}
418			toolCalls = append(toolCalls, toolCall)
419		}
420	}
421
422	return toolCalls
423}
424
425func (a *anthropicClient) usage(msg anthropic.Message) TokenUsage {
426	return TokenUsage{
427		InputTokens:         msg.Usage.InputTokens,
428		OutputTokens:        msg.Usage.OutputTokens,
429		CacheCreationTokens: msg.Usage.CacheCreationInputTokens,
430		CacheReadTokens:     msg.Usage.CacheReadInputTokens,
431	}
432}
433
434func WithAnthropicBedrock(useBedrock bool) AnthropicOption {
435	return func(options *anthropicOptions) {
436		options.useBedrock = useBedrock
437	}
438}
439
440func WithAnthropicDisableCache() AnthropicOption {
441	return func(options *anthropicOptions) {
442		options.disableCache = true
443	}
444}
445
446func DefaultShouldThinkFn(s string) bool {
447	return strings.Contains(strings.ToLower(s), "think")
448}
449
450func WithAnthropicShouldThinkFn(fn func(string) bool) AnthropicOption {
451	return func(options *anthropicOptions) {
452		options.shouldThink = fn
453	}
454}