1package provider
2
3import (
4 "context"
5 "encoding/json"
6 "errors"
7 "fmt"
8 "io"
9 "log/slog"
10 "regexp"
11 "strconv"
12 "strings"
13 "time"
14
15 "github.com/anthropics/anthropic-sdk-go"
16 "github.com/anthropics/anthropic-sdk-go/bedrock"
17 "github.com/anthropics/anthropic-sdk-go/option"
18 "github.com/anthropics/anthropic-sdk-go/vertex"
19 "github.com/charmbracelet/catwalk/pkg/catwalk"
20 "github.com/charmbracelet/crush/internal/config"
21 "github.com/charmbracelet/crush/internal/llm/tools"
22 "github.com/charmbracelet/crush/internal/log"
23 "github.com/charmbracelet/crush/internal/message"
24)
25
26// Pre-compiled regex for parsing context limit errors.
27var contextLimitRegex = regexp.MustCompile(`input length and ` + "`max_tokens`" + ` exceed context limit: (\d+) \+ (\d+) > (\d+)`)
28
29type anthropicClient struct {
30 providerOptions providerClientOptions
31 tp AnthropicClientType
32 client anthropic.Client
33 adjustedMaxTokens int // Used when context limit is hit
34}
35
36type AnthropicClient ProviderClient
37
38type AnthropicClientType string
39
40const (
41 AnthropicClientTypeNormal AnthropicClientType = "normal"
42 AnthropicClientTypeBedrock AnthropicClientType = "bedrock"
43 AnthropicClientTypeVertex AnthropicClientType = "vertex"
44)
45
46func newAnthropicClient(opts providerClientOptions, tp AnthropicClientType) AnthropicClient {
47 return &anthropicClient{
48 providerOptions: opts,
49 tp: tp,
50 client: createAnthropicClient(opts, tp),
51 }
52}
53
54func createAnthropicClient(opts providerClientOptions, tp AnthropicClientType) anthropic.Client {
55 anthropicClientOptions := []option.RequestOption{}
56
57 // Check if Authorization header is provided in extra headers
58 hasBearerAuth := false
59 if opts.extraHeaders != nil {
60 for key := range opts.extraHeaders {
61 if strings.ToLower(key) == "authorization" {
62 hasBearerAuth = true
63 break
64 }
65 }
66 }
67
68 isBearerToken := strings.HasPrefix(opts.apiKey, "Bearer ")
69
70 if opts.apiKey != "" && !hasBearerAuth {
71 if isBearerToken {
72 slog.Debug("API key starts with 'Bearer ', using as Authorization header")
73 anthropicClientOptions = append(anthropicClientOptions, option.WithHeader("Authorization", opts.apiKey))
74 } else {
75 // Use standard X-Api-Key header
76 anthropicClientOptions = append(anthropicClientOptions, option.WithAPIKey(opts.apiKey))
77 }
78 } else if hasBearerAuth {
79 slog.Debug("Skipping X-Api-Key header because Authorization header is provided")
80 }
81
82 if config.Get().Options.Debug {
83 httpClient := log.NewHTTPClient()
84 anthropicClientOptions = append(anthropicClientOptions, option.WithHTTPClient(httpClient))
85 }
86
87 switch tp {
88 case AnthropicClientTypeBedrock:
89 anthropicClientOptions = append(anthropicClientOptions, bedrock.WithLoadDefaultConfig(context.Background()))
90 case AnthropicClientTypeVertex:
91 project := opts.extraParams["project"]
92 location := opts.extraParams["location"]
93 anthropicClientOptions = append(anthropicClientOptions, vertex.WithGoogleAuth(context.Background(), location, project))
94 }
95 for key, header := range opts.extraHeaders {
96 anthropicClientOptions = append(anthropicClientOptions, option.WithHeaderAdd(key, header))
97 }
98 for key, value := range opts.extraBody {
99 anthropicClientOptions = append(anthropicClientOptions, option.WithJSONSet(key, value))
100 }
101 return anthropic.NewClient(anthropicClientOptions...)
102}
103
104func (a *anthropicClient) convertMessages(messages []message.Message) (anthropicMessages []anthropic.MessageParam) {
105 for i, msg := range messages {
106 cache := false
107 if i > len(messages)-3 {
108 cache = true
109 }
110 switch msg.Role {
111 case message.User:
112 content := anthropic.NewTextBlock(msg.Content().String())
113 if cache && !a.providerOptions.disableCache {
114 content.OfText.CacheControl = anthropic.CacheControlEphemeralParam{
115 Type: "ephemeral",
116 }
117 }
118 var contentBlocks []anthropic.ContentBlockParamUnion
119 contentBlocks = append(contentBlocks, content)
120 for _, binaryContent := range msg.BinaryContent() {
121 base64Image := binaryContent.String(catwalk.InferenceProviderAnthropic)
122 imageBlock := anthropic.NewImageBlockBase64(binaryContent.MIMEType, base64Image)
123 contentBlocks = append(contentBlocks, imageBlock)
124 }
125 anthropicMessages = append(anthropicMessages, anthropic.NewUserMessage(contentBlocks...))
126
127 case message.Assistant:
128 blocks := []anthropic.ContentBlockParamUnion{}
129
130 // Add thinking blocks first if present (required when thinking is enabled with tool use)
131 if reasoningContent := msg.ReasoningContent(); reasoningContent.Thinking != "" {
132 thinkingBlock := anthropic.NewThinkingBlock(reasoningContent.Signature, reasoningContent.Thinking)
133 blocks = append(blocks, thinkingBlock)
134 }
135
136 if msg.Content().String() != "" {
137 content := anthropic.NewTextBlock(msg.Content().String())
138 if cache && !a.providerOptions.disableCache {
139 content.OfText.CacheControl = anthropic.CacheControlEphemeralParam{
140 Type: "ephemeral",
141 }
142 }
143 blocks = append(blocks, content)
144 }
145
146 for _, toolCall := range msg.ToolCalls() {
147 var inputMap map[string]any
148 err := json.Unmarshal([]byte(toolCall.Input), &inputMap)
149 if err != nil {
150 continue
151 }
152 blocks = append(blocks, anthropic.NewToolUseBlock(toolCall.ID, inputMap, toolCall.Name))
153 }
154
155 if len(blocks) == 0 {
156 continue
157 }
158 anthropicMessages = append(anthropicMessages, anthropic.NewAssistantMessage(blocks...))
159
160 case message.Tool:
161 results := make([]anthropic.ContentBlockParamUnion, len(msg.ToolResults()))
162 for i, toolResult := range msg.ToolResults() {
163 results[i] = anthropic.NewToolResultBlock(toolResult.ToolCallID, toolResult.Content, toolResult.IsError)
164 }
165 anthropicMessages = append(anthropicMessages, anthropic.NewUserMessage(results...))
166 }
167 }
168 return
169}
170
171func (a *anthropicClient) convertTools(tools []tools.BaseTool) []anthropic.ToolUnionParam {
172 if len(tools) == 0 {
173 return nil
174 }
175 anthropicTools := make([]anthropic.ToolUnionParam, len(tools))
176
177 for i, tool := range tools {
178 info := tool.Info()
179 toolParam := anthropic.ToolParam{
180 Name: info.Name,
181 Description: anthropic.String(info.Description),
182 InputSchema: anthropic.ToolInputSchemaParam{
183 Properties: info.Parameters,
184 Required: info.Required,
185 },
186 }
187
188 if i == len(tools)-1 && !a.providerOptions.disableCache {
189 toolParam.CacheControl = anthropic.CacheControlEphemeralParam{
190 Type: "ephemeral",
191 }
192 }
193
194 anthropicTools[i] = anthropic.ToolUnionParam{OfTool: &toolParam}
195 }
196
197 return anthropicTools
198}
199
200func (a *anthropicClient) finishReason(reason string) message.FinishReason {
201 switch reason {
202 case "end_turn":
203 return message.FinishReasonEndTurn
204 case "max_tokens":
205 return message.FinishReasonMaxTokens
206 case "tool_use":
207 return message.FinishReasonToolUse
208 case "stop_sequence":
209 return message.FinishReasonEndTurn
210 default:
211 return message.FinishReasonUnknown
212 }
213}
214
215func (a *anthropicClient) isThinkingEnabled() bool {
216 cfg := config.Get()
217 modelConfig := cfg.Models[config.SelectedModelTypeLarge]
218 if a.providerOptions.modelType == config.SelectedModelTypeSmall {
219 modelConfig = cfg.Models[config.SelectedModelTypeSmall]
220 }
221 return a.Model().CanReason && modelConfig.Think
222}
223
224func (a *anthropicClient) preparedMessages(messages []anthropic.MessageParam, tools []anthropic.ToolUnionParam) anthropic.MessageNewParams {
225 model := a.providerOptions.model(a.providerOptions.modelType)
226 var thinkingParam anthropic.ThinkingConfigParamUnion
227 cfg := config.Get()
228 modelConfig := cfg.Models[config.SelectedModelTypeLarge]
229 if a.providerOptions.modelType == config.SelectedModelTypeSmall {
230 modelConfig = cfg.Models[config.SelectedModelTypeSmall]
231 }
232 temperature := anthropic.Float(0)
233
234 maxTokens := model.DefaultMaxTokens
235 if modelConfig.MaxTokens > 0 {
236 maxTokens = modelConfig.MaxTokens
237 }
238 if a.isThinkingEnabled() {
239 thinkingParam = anthropic.ThinkingConfigParamOfEnabled(int64(float64(maxTokens) * 0.8))
240 temperature = anthropic.Float(1)
241 }
242 // Override max tokens if set in provider options
243 if a.providerOptions.maxTokens > 0 {
244 maxTokens = a.providerOptions.maxTokens
245 }
246
247 // Use adjusted max tokens if context limit was hit
248 if a.adjustedMaxTokens > 0 {
249 maxTokens = int64(a.adjustedMaxTokens)
250 }
251
252 systemBlocks := []anthropic.TextBlockParam{}
253
254 // Add custom system prompt prefix if configured
255 if a.providerOptions.systemPromptPrefix != "" {
256 systemBlocks = append(systemBlocks, anthropic.TextBlockParam{
257 Text: a.providerOptions.systemPromptPrefix,
258 })
259 }
260
261 systemBlocks = append(systemBlocks, anthropic.TextBlockParam{
262 Text: a.providerOptions.systemMessage,
263 CacheControl: anthropic.CacheControlEphemeralParam{
264 Type: "ephemeral",
265 },
266 })
267
268 return anthropic.MessageNewParams{
269 Model: anthropic.Model(model.ID),
270 MaxTokens: maxTokens,
271 Temperature: temperature,
272 Messages: messages,
273 Tools: tools,
274 Thinking: thinkingParam,
275 System: systemBlocks,
276 }
277}
278
279func (a *anthropicClient) send(ctx context.Context, messages []message.Message, tools []tools.BaseTool) (response *ProviderResponse, err error) {
280 attempts := 0
281 for {
282 attempts++
283 // Prepare messages on each attempt in case max_tokens was adjusted
284 preparedMessages := a.preparedMessages(a.convertMessages(messages), a.convertTools(tools))
285
286 var opts []option.RequestOption
287 if a.isThinkingEnabled() {
288 opts = append(opts, option.WithHeaderAdd("anthropic-beta", "interleaved-thinking-2025-05-14"))
289 }
290 anthropicResponse, err := a.client.Messages.New(
291 ctx,
292 preparedMessages,
293 opts...,
294 )
295 // If there is an error we are going to see if we can retry the call
296 if err != nil {
297 retry, after, retryErr := a.shouldRetry(attempts, err)
298 if retryErr != nil {
299 return nil, retryErr
300 }
301 if retry {
302 slog.Warn("Retrying due to rate limit", "attempt", attempts, "max_retries", maxRetries, "error", err)
303 select {
304 case <-ctx.Done():
305 return nil, ctx.Err()
306 case <-time.After(time.Duration(after) * time.Millisecond):
307 continue
308 }
309 }
310 return nil, retryErr
311 }
312
313 content := ""
314 for _, block := range anthropicResponse.Content {
315 if text, ok := block.AsAny().(anthropic.TextBlock); ok {
316 content += text.Text
317 }
318 }
319
320 return &ProviderResponse{
321 Content: content,
322 ToolCalls: a.toolCalls(*anthropicResponse),
323 Usage: a.usage(*anthropicResponse),
324 }, nil
325 }
326}
327
328func (a *anthropicClient) stream(ctx context.Context, messages []message.Message, tools []tools.BaseTool) <-chan ProviderEvent {
329 attempts := 0
330 eventChan := make(chan ProviderEvent)
331 go func() {
332 for {
333 attempts++
334 // Prepare messages on each attempt in case max_tokens was adjusted
335 preparedMessages := a.preparedMessages(a.convertMessages(messages), a.convertTools(tools))
336
337 var opts []option.RequestOption
338 if a.isThinkingEnabled() {
339 opts = append(opts, option.WithHeaderAdd("anthropic-beta", "interleaved-thinking-2025-05-14"))
340 }
341
342 anthropicStream := a.client.Messages.NewStreaming(
343 ctx,
344 preparedMessages,
345 opts...,
346 )
347 accumulatedMessage := anthropic.Message{}
348
349 currentToolCallID := ""
350 for anthropicStream.Next() {
351 event := anthropicStream.Current()
352 err := accumulatedMessage.Accumulate(event)
353 if err != nil {
354 slog.Warn("Error accumulating message", "error", err)
355 continue
356 }
357
358 switch event := event.AsAny().(type) {
359 case anthropic.ContentBlockStartEvent:
360 switch event.ContentBlock.Type {
361 case "text":
362 eventChan <- ProviderEvent{Type: EventContentStart}
363 case "tool_use":
364 currentToolCallID = event.ContentBlock.ID
365 eventChan <- ProviderEvent{
366 Type: EventToolUseStart,
367 ToolCall: &message.ToolCall{
368 ID: event.ContentBlock.ID,
369 Name: event.ContentBlock.Name,
370 Finished: false,
371 },
372 }
373 }
374
375 case anthropic.ContentBlockDeltaEvent:
376 if event.Delta.Type == "thinking_delta" && event.Delta.Thinking != "" {
377 eventChan <- ProviderEvent{
378 Type: EventThinkingDelta,
379 Thinking: event.Delta.Thinking,
380 }
381 } else if event.Delta.Type == "signature_delta" && event.Delta.Signature != "" {
382 eventChan <- ProviderEvent{
383 Type: EventSignatureDelta,
384 Signature: event.Delta.Signature,
385 }
386 } else if event.Delta.Type == "text_delta" && event.Delta.Text != "" {
387 eventChan <- ProviderEvent{
388 Type: EventContentDelta,
389 Content: event.Delta.Text,
390 }
391 } else if event.Delta.Type == "input_json_delta" {
392 if currentToolCallID != "" {
393 eventChan <- ProviderEvent{
394 Type: EventToolUseDelta,
395 ToolCall: &message.ToolCall{
396 ID: currentToolCallID,
397 Finished: false,
398 Input: event.Delta.PartialJSON,
399 },
400 }
401 }
402 }
403 case anthropic.ContentBlockStopEvent:
404 if currentToolCallID != "" {
405 eventChan <- ProviderEvent{
406 Type: EventToolUseStop,
407 ToolCall: &message.ToolCall{
408 ID: currentToolCallID,
409 },
410 }
411 currentToolCallID = ""
412 } else {
413 eventChan <- ProviderEvent{Type: EventContentStop}
414 }
415
416 case anthropic.MessageStopEvent:
417 content := ""
418 for _, block := range accumulatedMessage.Content {
419 if text, ok := block.AsAny().(anthropic.TextBlock); ok {
420 content += text.Text
421 }
422 }
423
424 eventChan <- ProviderEvent{
425 Type: EventComplete,
426 Response: &ProviderResponse{
427 Content: content,
428 ToolCalls: a.toolCalls(accumulatedMessage),
429 Usage: a.usage(accumulatedMessage),
430 FinishReason: a.finishReason(string(accumulatedMessage.StopReason)),
431 },
432 Content: content,
433 }
434 }
435 }
436
437 err := anthropicStream.Err()
438 if err == nil || errors.Is(err, io.EOF) {
439 close(eventChan)
440 return
441 }
442
443 // If there is an error we are going to see if we can retry the call
444 retry, after, retryErr := a.shouldRetry(attempts, err)
445 if retryErr != nil {
446 eventChan <- ProviderEvent{Type: EventError, Error: retryErr}
447 close(eventChan)
448 return
449 }
450 if retry {
451 slog.Warn("Retrying due to rate limit", "attempt", attempts, "max_retries", maxRetries, "error", err)
452 select {
453 case <-ctx.Done():
454 // context cancelled
455 if ctx.Err() != nil {
456 eventChan <- ProviderEvent{Type: EventError, Error: ctx.Err()}
457 }
458 close(eventChan)
459 return
460 case <-time.After(time.Duration(after) * time.Millisecond):
461 continue
462 }
463 }
464 if ctx.Err() != nil {
465 eventChan <- ProviderEvent{Type: EventError, Error: ctx.Err()}
466 }
467
468 close(eventChan)
469 return
470 }
471 }()
472 return eventChan
473}
474
475func (a *anthropicClient) shouldRetry(attempts int, err error) (bool, int64, error) {
476 var apiErr *anthropic.Error
477 if !errors.As(err, &apiErr) {
478 return false, 0, err
479 }
480
481 if attempts > maxRetries {
482 return false, 0, fmt.Errorf("maximum retry attempts reached for rate limit: %d retries", maxRetries)
483 }
484
485 if apiErr.StatusCode == 401 {
486 a.providerOptions.apiKey, err = config.Get().Resolve(a.providerOptions.config.APIKey)
487 if err != nil {
488 return false, 0, fmt.Errorf("failed to resolve API key: %w", err)
489 }
490 a.client = createAnthropicClient(a.providerOptions, a.tp)
491 return true, 0, nil
492 }
493
494 // Handle context limit exceeded error (400 Bad Request)
495 if apiErr.StatusCode == 400 {
496 if adjusted, ok := a.handleContextLimitError(apiErr); ok {
497 a.adjustedMaxTokens = adjusted
498 slog.Debug("Adjusted max_tokens due to context limit", "new_max_tokens", adjusted)
499 return true, 0, nil
500 }
501 }
502
503 isOverloaded := strings.Contains(apiErr.Error(), "overloaded") || strings.Contains(apiErr.Error(), "rate limit exceeded")
504 if apiErr.StatusCode != 429 && apiErr.StatusCode != 529 && !isOverloaded {
505 return false, 0, err
506 }
507
508 retryMs := 0
509 retryAfterValues := apiErr.Response.Header.Values("Retry-After")
510
511 backoffMs := 2000 * (1 << (attempts - 1))
512 jitterMs := int(float64(backoffMs) * 0.2)
513 retryMs = backoffMs + jitterMs
514 if len(retryAfterValues) > 0 {
515 if _, err := fmt.Sscanf(retryAfterValues[0], "%d", &retryMs); err == nil {
516 retryMs = retryMs * 1000
517 }
518 }
519 return true, int64(retryMs), nil
520}
521
522// handleContextLimitError parses context limit error and returns adjusted max_tokens
523func (a *anthropicClient) handleContextLimitError(apiErr *anthropic.Error) (int, bool) {
524 // Parse error message like: "input length and max_tokens exceed context limit: 154978 + 50000 > 200000"
525 errorMsg := apiErr.Error()
526
527 matches := contextLimitRegex.FindStringSubmatch(errorMsg)
528
529 if len(matches) != 4 {
530 return 0, false
531 }
532
533 inputTokens, err1 := strconv.Atoi(matches[1])
534 contextLimit, err2 := strconv.Atoi(matches[3])
535
536 if err1 != nil || err2 != nil {
537 return 0, false
538 }
539
540 // Calculate safe max_tokens with a buffer of 1000 tokens
541 safeMaxTokens := contextLimit - inputTokens - 1000
542
543 // Ensure we don't go below a minimum threshold
544 safeMaxTokens = max(safeMaxTokens, 1000)
545
546 return safeMaxTokens, true
547}
548
549func (a *anthropicClient) toolCalls(msg anthropic.Message) []message.ToolCall {
550 var toolCalls []message.ToolCall
551
552 for _, block := range msg.Content {
553 switch variant := block.AsAny().(type) {
554 case anthropic.ToolUseBlock:
555 toolCall := message.ToolCall{
556 ID: variant.ID,
557 Name: variant.Name,
558 Input: string(variant.Input),
559 Type: string(variant.Type),
560 Finished: true,
561 }
562 toolCalls = append(toolCalls, toolCall)
563 }
564 }
565
566 return toolCalls
567}
568
569func (a *anthropicClient) usage(msg anthropic.Message) TokenUsage {
570 return TokenUsage{
571 InputTokens: msg.Usage.InputTokens,
572 OutputTokens: msg.Usage.OutputTokens,
573 CacheCreationTokens: msg.Usage.CacheCreationInputTokens,
574 CacheReadTokens: msg.Usage.CacheReadInputTokens,
575 }
576}
577
578func (a *anthropicClient) Model() catwalk.Model {
579 return a.providerOptions.model(a.providerOptions.modelType)
580}