claude-code-best/src/services/api/openai/streamAdapter.ts
uk0 e88dcb2f9e fix: OpenAI adapter tool calling compatibility
Two fixes for OpenAI-compatible provider compatibility:

1. Sanitize JSON Schema `const` → `enum` in tool parameters.
   Many OpenAI-compatible endpoints (Ollama, DeepSeek, vLLM, etc.)
   do not support the `const` keyword in JSON Schema. Recursively
   convert `const: value` to `enum: [value]` which is semantically
   equivalent.

2. Force stop_reason to `tool_use` when tool_calls are present.
   Some backends incorrectly return finish_reason "stop" even when
   the response contains tool_calls. Without this fix, the query
   loop treats the response as a normal end_turn and never executes
   the requested tools.
2026-04-06 13:31:28 +08:00

315 lines
9.5 KiB
TypeScript

import type { BetaRawMessageStreamEvent } from '@anthropic-ai/sdk/resources/beta/messages/messages.mjs'
import type { ChatCompletionChunk } from 'openai/resources/chat/completions/completions.mjs'
import { randomUUID } from 'crypto'
/**
* Adapt an OpenAI streaming response into Anthropic BetaRawMessageStreamEvent.
*
* Mapping:
* First chunk → message_start
* delta.reasoning_content → content_block_start(thinking) + thinking_delta + content_block_stop
* delta.content → content_block_start(text) + text_delta + content_block_stop
* delta.tool_calls → content_block_start(tool_use) + input_json_delta + content_block_stop
* finish_reason → message_delta(stop_reason) + message_stop
* usage.cached_tokens → cache_read_input_tokens in message_start usage
*
* Thinking support:
* DeepSeek and compatible providers send `delta.reasoning_content` for chain-of-thought.
* This is mapped to Anthropic's `thinking` content blocks:
* content_block_start: { type: 'thinking', thinking: '', signature: '' }
* content_block_delta: { type: 'thinking_delta', thinking: '...' }
*
* Prompt caching:
* OpenAI reports cached tokens in usage.prompt_tokens_details.cached_tokens.
* This is mapped to Anthropic's cache_read_input_tokens.
*/
export async function* adaptOpenAIStreamToAnthropic(
stream: AsyncIterable<ChatCompletionChunk>,
model: string,
): AsyncGenerator<BetaRawMessageStreamEvent, void> {
const messageId = `msg_${randomUUID().replace(/-/g, '').slice(0, 24)}`
let started = false
let currentContentIndex = -1
// Track tool_use blocks: tool_calls index → { contentIndex, id, name, arguments }
const toolBlocks = new Map<number, { contentIndex: number; id: string; name: string; arguments: string }>()
// Track thinking block state
let thinkingBlockOpen = false
// Track text block state
let textBlockOpen = false
// Track usage
let inputTokens = 0
let outputTokens = 0
let cachedTokens = 0
// Track all open content block indices (for cleanup)
const openBlockIndices = new Set<number>()
for await (const chunk of stream) {
const choice = chunk.choices?.[0]
const delta = choice?.delta
// Extract usage from any chunk that carries it
if (chunk.usage) {
inputTokens = chunk.usage.prompt_tokens ?? inputTokens
outputTokens = chunk.usage.completion_tokens ?? outputTokens
// OpenAI prompt caching: prompt_tokens_details.cached_tokens
const details = (chunk.usage as any).prompt_tokens_details
if (details?.cached_tokens) {
cachedTokens = details.cached_tokens
}
}
// Emit message_start on first chunk
if (!started) {
started = true
yield {
type: 'message_start',
message: {
id: messageId,
type: 'message',
role: 'assistant',
content: [],
model,
stop_reason: null,
stop_sequence: null,
usage: {
input_tokens: inputTokens,
output_tokens: 0,
cache_creation_input_tokens: 0,
cache_read_input_tokens: cachedTokens,
},
},
} as BetaRawMessageStreamEvent
}
if (!delta) continue
// Handle reasoning_content → Anthropic thinking block
// DeepSeek and compatible providers send delta.reasoning_content
const reasoningContent = (delta as any).reasoning_content
if (reasoningContent != null && reasoningContent !== '') {
if (!thinkingBlockOpen) {
currentContentIndex++
thinkingBlockOpen = true
openBlockIndices.add(currentContentIndex)
yield {
type: 'content_block_start',
index: currentContentIndex,
content_block: {
type: 'thinking',
thinking: '',
signature: '',
},
} as BetaRawMessageStreamEvent
}
yield {
type: 'content_block_delta',
index: currentContentIndex,
delta: {
type: 'thinking_delta',
thinking: reasoningContent,
},
} as BetaRawMessageStreamEvent
}
// Handle text content
if (delta.content != null && delta.content !== '') {
if (!textBlockOpen) {
// Close thinking block if still open (reasoning done, now generating answer)
if (thinkingBlockOpen) {
yield {
type: 'content_block_stop',
index: currentContentIndex,
} as BetaRawMessageStreamEvent
openBlockIndices.delete(currentContentIndex)
thinkingBlockOpen = false
}
currentContentIndex++
textBlockOpen = true
openBlockIndices.add(currentContentIndex)
yield {
type: 'content_block_start',
index: currentContentIndex,
content_block: {
type: 'text',
text: '',
},
} as BetaRawMessageStreamEvent
}
yield {
type: 'content_block_delta',
index: currentContentIndex,
delta: {
type: 'text_delta',
text: delta.content,
},
} as BetaRawMessageStreamEvent
}
// Handle tool calls
if (delta.tool_calls) {
for (const tc of delta.tool_calls) {
const tcIndex = tc.index
if (!toolBlocks.has(tcIndex)) {
// Close thinking block if open
if (thinkingBlockOpen) {
yield {
type: 'content_block_stop',
index: currentContentIndex,
} as BetaRawMessageStreamEvent
openBlockIndices.delete(currentContentIndex)
thinkingBlockOpen = false
}
// Close text block if open
if (textBlockOpen) {
yield {
type: 'content_block_stop',
index: currentContentIndex,
} as BetaRawMessageStreamEvent
openBlockIndices.delete(currentContentIndex)
textBlockOpen = false
}
// Start new tool_use block
currentContentIndex++
const toolId = tc.id || `toolu_${randomUUID().replace(/-/g, '').slice(0, 24)}`
const toolName = tc.function?.name || ''
toolBlocks.set(tcIndex, {
contentIndex: currentContentIndex,
id: toolId,
name: toolName,
arguments: '',
})
openBlockIndices.add(currentContentIndex)
yield {
type: 'content_block_start',
index: currentContentIndex,
content_block: {
type: 'tool_use',
id: toolId,
name: toolName,
input: {},
},
} as BetaRawMessageStreamEvent
}
// Stream argument fragments
const argFragment = tc.function?.arguments
if (argFragment) {
toolBlocks.get(tcIndex)!.arguments += argFragment
yield {
type: 'content_block_delta',
index: toolBlocks.get(tcIndex)!.contentIndex,
delta: {
type: 'input_json_delta',
partial_json: argFragment,
},
} as BetaRawMessageStreamEvent
}
}
}
// Handle finish
if (choice?.finish_reason) {
// Close thinking block if still open
if (thinkingBlockOpen) {
yield {
type: 'content_block_stop',
index: currentContentIndex,
} as BetaRawMessageStreamEvent
openBlockIndices.delete(currentContentIndex)
thinkingBlockOpen = false
}
// Close text block if still open
if (textBlockOpen) {
yield {
type: 'content_block_stop',
index: currentContentIndex,
} as BetaRawMessageStreamEvent
openBlockIndices.delete(currentContentIndex)
textBlockOpen = false
}
// Close all tool blocks that haven't been closed yet
for (const [, block] of toolBlocks) {
if (openBlockIndices.has(block.contentIndex)) {
yield {
type: 'content_block_stop',
index: block.contentIndex,
} as BetaRawMessageStreamEvent
openBlockIndices.delete(block.contentIndex)
}
}
// Map finish_reason to Anthropic stop_reason.
// Some backends return "stop" even when tool_calls are present —
// force "tool_use" when we saw any tool blocks to ensure the query
// loop actually executes the tools.
const hasToolCalls = toolBlocks.size > 0
const stopReason = hasToolCalls ? 'tool_use' : mapFinishReason(choice.finish_reason)
yield {
type: 'message_delta',
delta: {
stop_reason: stopReason,
stop_sequence: null,
},
usage: {
output_tokens: outputTokens,
},
} as BetaRawMessageStreamEvent
yield {
type: 'message_stop',
} as BetaRawMessageStreamEvent
}
}
// Safety: close any remaining open blocks if stream ended without finish_reason
for (const idx of openBlockIndices) {
yield {
type: 'content_block_stop',
index: idx,
} as BetaRawMessageStreamEvent
}
}
/**
* Map OpenAI finish_reason to Anthropic stop_reason.
*
* stop → end_turn
* tool_calls → tool_use
* length → max_tokens
* content_filter → end_turn
*/
function mapFinishReason(reason: string): string {
switch (reason) {
case 'stop':
return 'end_turn'
case 'tool_calls':
return 'tool_use'
case 'length':
return 'max_tokens'
case 'content_filter':
return 'end_turn'
default:
return 'end_turn'
}
}