222 lines
8 KiB
Python
222 lines
8 KiB
Python
"""路由: /v1/messages
|
||
|
||
Anthropic Messages API 透传。当 Cursor 直接发送 Anthropic 格式请求时，
|
||
直接转发到上游并原样返回。处理非标准的 reasoning_content 字段，
|
||
将其注入为标准的 thinking blocks。
|
||
"""
|
||
|
||
import json
|
||
import logging
|
||
|
||
import requests as req_lib
|
||
from flask import Blueprint, request, jsonify
|
||
|
||
import settings
|
||
from config import Config
|
||
from routes.common import apply_body_modifications, apply_header_modifications, inject_instructions_anthropic
|
||
from utils.http import build_anthropic_headers, forward_request, sse_response
|
||
from utils.request_logger import (
|
||
append_client_event,
|
||
append_upstream_event,
|
||
attach_client_response,
|
||
attach_error,
|
||
attach_upstream_request,
|
||
attach_upstream_response,
|
||
finalize_turn,
|
||
set_stream_summary,
|
||
start_turn,
|
||
)
|
||
|
||
logger = logging.getLogger(__name__)
|
||
|
||
bp = Blueprint('messages', __name__)
|
||
|
||
|
||
@bp.route('/v1/messages', methods=['POST'])
|
||
def messages_passthrough():
|
||
"""透传 Anthropic Messages 请求，并在必要时补齐 thinking 兼容层。"""
|
||
original_payload = request.get_json(force=True)
|
||
payload = json.loads(json.dumps(original_payload, ensure_ascii=False, default=str))
|
||
model = payload.get('model', 'unknown')
|
||
is_stream = payload.get('stream', False)
|
||
|
||
logger.info(f'[透传] model={model} 流式={is_stream}')
|
||
|
||
mapping = settings.resolve_model(model)
|
||
url_base = mapping['target_url']
|
||
api_key = mapping['api_key']
|
||
custom_instructions = mapping.get('custom_instructions', '')
|
||
instructions_position = mapping.get('instructions_position', 'prepend')
|
||
body_mods = mapping.get('body_modifications', {})
|
||
header_mods = mapping.get('header_modifications', {})
|
||
headers = build_anthropic_headers(api_key)
|
||
headers = apply_header_modifications(headers, header_mods)
|
||
url = f'{url_base.rstrip("/")}/v1/messages'
|
||
|
||
turn = start_turn(
|
||
route='messages',
|
||
client_model=model,
|
||
backend='anthropic',
|
||
stream=is_stream,
|
||
client_request=original_payload,
|
||
request_headers=dict(request.headers),
|
||
target_url=url_base,
|
||
upstream_model=model,
|
||
)
|
||
|
||
payload = inject_instructions_anthropic(payload, custom_instructions, instructions_position)
|
||
payload = apply_body_modifications(payload, body_mods)
|
||
|
||
if not is_stream:
|
||
attach_upstream_request(turn, payload, headers)
|
||
resp, err = forward_request(url, headers, payload)
|
||
if err:
|
||
attach_error(turn, {'stage': 'forward_request', 'message': 'upstream request failed'})
|
||
finalize_turn(turn)
|
||
return err
|
||
data = resp.json()
|
||
attach_upstream_response(turn, data)
|
||
_inject_thinking(data)
|
||
attach_client_response(turn, data)
|
||
finalize_turn(turn)
|
||
return jsonify(data)
|
||
|
||
def generate():
|
||
"""建立上游流式连接并逐段回传处理后的 SSE 数据。"""
|
||
attach_upstream_request(turn, payload, headers)
|
||
try:
|
||
resp = req_lib.post(
|
||
url, headers=headers, json=payload,
|
||
timeout=Config.API_TIMEOUT, stream=True,
|
||
)
|
||
if resp.status_code != 200:
|
||
body = resp.content.decode('utf-8', errors='replace')
|
||
logger.warning(f'上游返回 {resp.status_code}: {body[:300]}')
|
||
attach_error(turn, {'stage': 'upstream_status', 'status_code': resp.status_code, 'message': body})
|
||
set_stream_summary(turn, {'status': 'error'})
|
||
finalize_turn(turn)
|
||
yield f'data: {json.dumps({"error": {"message": body, "type": "upstream_error"}})}\n\n'
|
||
return
|
||
|
||
summary = {'upstream_event_count': 0, 'client_event_count': 0}
|
||
client_events = []
|
||
for out in _process_stream(resp, turn=turn, summary=summary):
|
||
client_events.append(out)
|
||
yield out
|
||
set_stream_summary(turn, summary)
|
||
attach_client_response(turn, {
|
||
'type': 'messages.stream.summary',
|
||
'event_count': len(client_events),
|
||
})
|
||
finalize_turn(turn)
|
||
except req_lib.RequestException as e:
|
||
logger.error(f'请求上游失败: {e}')
|
||
attach_error(turn, {'stage': 'request_exception', 'message': str(e)})
|
||
set_stream_summary(turn, {'status': 'error'})
|
||
finalize_turn(turn)
|
||
yield f'data: {json.dumps({"error": {"message": str(e), "type": "proxy_error"}})}\n\n'
|
||
|
||
return sse_response(generate())
|
||
|
||
|
||
# ─── 内部辅助 ─────────────────────────────────────
|
||
|
||
|
||
def _inject_thinking(data):
|
||
"""将非标准 reasoning_content 字段注入为 Anthropic thinking block"""
|
||
rc = data.pop('reasoning_content', None) or data.pop('reasoningContent', None)
|
||
if not rc:
|
||
return
|
||
|
||
content = data.get('content')
|
||
if not isinstance(content, list):
|
||
content = []
|
||
|
||
# 避免重复注入
|
||
if any(isinstance(b, dict) and b.get('type') == 'thinking' for b in content):
|
||
return
|
||
|
||
content.insert(0, {'type': 'thinking', 'thinking': rc})
|
||
data['content'] = content
|
||
logger.info(f'已注入 thinking block ({len(rc)} 字符)')
|
||
|
||
|
||
def _process_stream(resp, *, turn=None, summary: dict[str, int] | None = None):
|
||
"""处理 /v1/messages 流式响应，检测并注入 thinking 事件
|
||
|
||
追踪上游 content block 的 index，在注入 thinking blocks 时使用独立的 index，
|
||
并将后续上游 block 的 index 偏移，避免冲突。
|
||
"""
|
||
reasoning_buf = ''
|
||
injected = False
|
||
index_offset = 0
|
||
if summary is None:
|
||
summary = {'upstream_event_count': 0, 'client_event_count': 0}
|
||
|
||
for line in resp.iter_lines():
|
||
if not line:
|
||
continue
|
||
decoded = line.decode('utf-8', errors='replace')
|
||
append_upstream_event(turn, {'raw': decoded})
|
||
summary['upstream_event_count'] += 1
|
||
|
||
if not decoded.startswith('data:'):
|
||
yield decoded + '\n\n'
|
||
continue
|
||
|
||
data_str = decoded[5:].strip()
|
||
if not data_str:
|
||
yield decoded + '\n\n'
|
||
continue
|
||
|
||
try:
|
||
event_data = json.loads(data_str)
|
||
except json.JSONDecodeError:
|
||
yield decoded + '\n\n'
|
||
continue
|
||
|
||
modified = False
|
||
|
||
for container_key in ('message', 'delta'):
|
||
container = event_data.get(container_key)
|
||
if not container:
|
||
continue
|
||
rc = container.pop('reasoning_content', None) or container.pop('reasoningContent', None)
|
||
if rc:
|
||
reasoning_buf += rc
|
||
modified = True
|
||
|
||
if reasoning_buf and not injected:
|
||
if event_data.get('delta', {}).get('type') == 'text_delta':
|
||
injected = True
|
||
for injected_event in _emit_thinking_blocks(reasoning_buf):
|
||
append_client_event(turn, {'raw': injected_event})
|
||
summary['client_event_count'] += 1
|
||
yield injected_event
|
||
index_offset = 1
|
||
reasoning_buf = ''
|
||
|
||
if index_offset and 'index' in event_data:
|
||
event_data['index'] = event_data['index'] + index_offset
|
||
modified = True
|
||
|
||
output = f'data: {json.dumps(event_data)}\n\n' if modified else decoded + '\n\n'
|
||
append_client_event(turn, {'raw': output})
|
||
summary['client_event_count'] += 1
|
||
yield output
|
||
|
||
|
||
def _emit_thinking_blocks(text):
|
||
"""生成一组等价的 Anthropic thinking block SSE 事件。"""
|
||
yield (
|
||
f'event: content_block_start\n'
|
||
f'data: {json.dumps({"type": "content_block_start", "index": 0, "content_block": {"type": "thinking", "thinking": ""}})}\n\n'
|
||
)
|
||
yield (
|
||
f'event: content_block_delta\n'
|
||
f'data: {json.dumps({"type": "content_block_delta", "index": 0, "delta": {"type": "thinking_delta", "thinking": text}})}\n\n'
|
||
)
|
||
yield (
|
||
f'event: content_block_stop\n'
|
||
f'data: {json.dumps({"type": "content_block_stop", "index": 0})}\n\n'
|
||
)
|