BadRequestError: System message must be at the beginning.

问答报错
  └─ 是不是模型端拒绝？(400 + "System message must be at the beginning")
        ├─ 是 → 看 Dify 实际发给模型的 messages 长什么样（抓出站日志）
        │        └─ 若多条 system / 含空 system → 根因确认：Qwen3 只接受单条 system
        └─ 否  → 看是不是端点不可达(B) 或 工具解析(C)

    # DEBUG: dump messages before sending to vLLM/Qwen
    try:
        with open('/tmp/dify_openai_messages.log', 'a', encoding='utf-8') as _df:
            _df.write('--- model=%s stream=%s ---\n' % (model, stream))
            _df.write(json.dumps(
                [message(item) for item in _ensure_system_first(prompt_messages)],
                ensure_ascii=False, indent=2))
            _df.write('\n\n')
    except Exception as _e:
        pass

#!/usr/bin/env bash
set -euo pipefail

cd /dify/dify-main/docker && docker compose restart plugin_daemon
# 清空旧日志
docker exec docker-plugin_daemon-1 sh -c 'rm -f /tmp/dify_openai_messages.log && touch /tmp/dify_openai_messages.log'

#!/usr/bin/env bash
set -euo pipefail

docker exec docker-plugin_daemon-1 cat /tmp/dify_openai_messages.log

[
  {"role": "system", "content": "你是企业内部知识助手..."},        // 知识库助手提示
  {"role": "system", "content": "You can run commands in an isolated shell workspace..."}, // Agent shell 工具提示
  {"role": "system", "content": ""},                                // ← 一条空 system
  {"role": "system", "content": "Current Agent config manifest..."},// Agent 配置
  {"role": "system", "content": "Environment variables may contain..."}, // 环境变量提示
  {"role": "user",   "content": "描述考勤与请休假管理制度的目的"}
]

#!/usr/bin/env bash
set -euo pipefail

BASE=http://116.62.10.183:8000/v1/chat/completions
AUTH='Authorization: Bearer 123456'
H='Content-Type: application/json'

# TEST1：两条 system → 必报错
curl -s -X POST $BASE -H "$H" -H "$AUTH" -d '{
  "model":"qwen3.6-27b",
  "messages":[{"role":"system","content":"A"},{"role":"system","content":"B"},{"role":"user","content":"hi"}]
}'

# TEST2：含空 system → 必报错
curl -s -X POST $BASE -H "$H" -H "$AUTH" -d '{
  "model":"qwen3.6-27b",
  "messages":[{"role":"system","content":"A"},{"role":"system","content":""},{"role":"system","content":"C"},{"role":"user","content":"hi"}]
}'

# TEST3：合并成单条 system → 成功
curl -s -X POST $BASE -H "$H" -H "$AUTH" -d '{
  "model":"qwen3.6-27b",
  "messages":[{"role":"system","content":"A\n\nB\n\nC"},{"role":"user","content":"hi"}]
}'

def _ensure_system_first(messages: list[PromptMessage]) -> list[PromptMessage]:
    """Qwen3/vLLM chat templates accept ONLY one system message, at the start.

    Dify (esp. Agent apps) stacks several system/developer prompts: KB assistant
    prompt + agent tool prompt + an empty system + config manifest... Merging them
    into a single system message (joined by blank lines, empties dropped) keeps it
    at the front; every other message keeps its original relative order.
    """
    system_parts: list[str] = []
    rest: list[PromptMessage] = []
    for m in messages:
        if isinstance(m, (SystemPromptMessage, DeveloperPromptMessage)):
            text = _text_content(m)
            if text.strip():
                system_parts.append(text)
        else:
            rest.append(m)
    if system_parts:
        rest.insert(0, SystemPromptMessage(content="\n\n".join(system_parts)))
    return rest

def _text_content(prompt: PromptMessage) -> str:
    if isinstance(prompt.content, str):
        return prompt.content
    content = prompt.content or []
    if any(item.type != PromptMessageContentType.TEXT for item in content):
        raise InvokeBadRequestError(
            f"{prompt.role.value} messages only support text content"
        )
    return "".join(cast(TextPromptMessageContent, item).data for item in content)

    response = client.chat.completions.create(
        model=model,
        messages=cast(Any, [message(item) for item in _ensure_system_first(prompt_messages)]),
        stream=stream  # 其余参数不变
        ...
    )

#!/usr/bin/env bash
set -euo pipefail

cd /dify/dify-main/docker && docker compose restart plugin_daemon

#!/usr/bin/env bash
set -euo pipefail

BASE=http://192.168.110.207/v1
APIK=app-v9yYVTQTrUoSFHNqAhufSGmh

curl -s -N -X POST $BASE/chat-messages \
  -H "Authorization: Bearer $APIK" \
  -H "Content-Type: application/json" \
  -d '{
    "inputs": {},
    "query": "描述考勤与请休假管理制度的目的",
    "response_mode": "streaming",
    "user": "debug-workbuddy"
  }'

#!/usr/bin/env bash
set -euo pipefail

# 在 Dify 服务器上
docker ps --filter name=vllm-qwen3.6-27b        # 容器是否 running
docker logs --tail 20 vllm-qwen3.6-27b          # 是否 "Application startup complete"
curl -s http://116.62.10.183:8000/v1/models     # 端口是否通、模型是否列出

#!/usr/bin/env bash
set -euo pipefail

docker.m.daocloud.io/vllm/vllm-openai:latest \
  /model \
  --trust-remote-code --dtype bfloat16 --tensor-parallel-size 1 \
  --enable-auto-tool-choice --tool-call-parser qwen3_xml --reasoning-parser qwen3 \
  --max-model-len 65536 --gpu-memory-utilization 0.75 --max-num-seqs 8 \
  --served-model-name qwen3.6-27b --enable-prefix-caching --host 0.0.0.0 --port 8000

#!/usr/bin/env bash
set -euo pipefail

# 加日志位置：client.chat.completions.create(...) 之前
#   with open('/tmp/dify_openai_messages.log','a') as f: f.write(json.dumps([...]))
cd /dify/dify-main/docker && docker compose restart plugin_daemon
docker exec docker-plugin_daemon-1 sh -c 'rm -f /tmp/dify_openai_messages.log'
docker exec docker-plugin_daemon-1 cat /tmp/dify_openai_messages.log

#!/usr/bin/env bash
set -euo pipefail

cd /dify/dify-main/docker && docker compose restart plugin_daemon
sleep 8 && docker ps --filter name=plugin_daemon --format '{{.Names}} {{.Status}}'

#!/usr/bin/env bash
set -euo pipefail

docker logs docker-plugin_daemon-1 2>&1 | grep -iE 'error|syntax|traceback' | tail -20   # 无报错即 OK

#!/usr/bin/env bash
set -euo pipefail

curl -s -N -X POST http://192.168.110.207/v1/chat-messages \
  -H "Authorization: Bearer app-v9yYVTQTrUoSFHNqAhufSGmh" \
  -H "Content-Type: application/json" \
  -d '{"inputs":{},"query":"描述考勤与请休假管理制度的目的","response_mode":"streaming","user":"debug"}'

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""专题四 · 步骤 1：在 chat.py 注入临时调试日志（验证后请运行删日志脚本）。"""
from __future__ import annotations

import sys

import _bootstrap  # noqa: F401
import _config as C
import _plugin_patch as P
from dify_api import Dify


def main() -> int:
    d = Dify(C.DIFY_EMAIL, C.DIFY_PASSWORD)
    try:
        d.login()
        chat_path = P.find_plugin_file(d, "chat.py")
        print("chat.py:", chat_path)
        content = P.read_remote_file(d, chat_path)
        new_content = P.inject_debug_log(content)
        P.deploy_plugin_file(d, chat_path, new_content)
        d.sh(
            "docker exec %s sh -c 'rm -f /tmp/dify_openai_messages.log && "
            "touch /tmp/dify_openai_messages.log'" % C.PLUGIN_CONTAINER
        )
        print("已重启 plugin_daemon 并清空 /tmp/dify_openai_messages.log")
        return 0
    finally:
        d.close()


if __name__ == "__main__":
    sys.exit(main())

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""专题四 · 步骤 2：读取 plugin_daemon 容器内出站 messages 调试日志。"""
from __future__ import annotations

import sys

import _bootstrap  # noqa: F401
import _config as C
from dify_api import Dify


def main() -> int:
    d = Dify(C.DIFY_EMAIL, C.DIFY_PASSWORD)
    try:
        d.login()
        out, err = d.sh(
            "docker exec %s cat /tmp/dify_openai_messages.log" % C.PLUGIN_CONTAINER
        )
        text = out or err
        if not text.strip():
            print("[提示] 日志为空。请先在 Agent 里发一条问题触发报错，再运行本脚本。")
            return 1
        print(text)
        return 0
    finally:
        d.close()


if __name__ == "__main__":
    sys.exit(main())

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""专题四 · 步骤 3：直连 vLLM 复现多条/空 system 与合并后成功。"""
from __future__ import annotations

import json
import sys

import _bootstrap  # noqa: F401
import _config as C
from dify_api import Dify


def curl_chat(d: Dify, messages: list[dict], label: str) -> None:
    body = json.dumps({"model": C.LLM_MODEL, "messages": messages})
    remote = "/tmp/vllm_sys_test.json"
    with d.sftp.open(remote, "w") as f:
        f.write(body)
    cmd = (
        "curl -s -X POST %s/v1/chat/completions "
        "-H 'Content-Type: application/json' "
        "-H 'Authorization: Bearer %s' "
        "-d @%s" % (C.VLLM_URL, C.VLLM_KEY, remote)
    )
    out, err = d.sh(cmd, t=120)
    print("\n=== %s ===" % label)
    print(out or err)
    try:
        j = json.loads(out)
        err_msg = j.get("error", {}).get("message") or j.get("message")
        if err_msg:
            print("[error]", err_msg)
    except Exception:
        pass


def main() -> int:
    d = Dify(C.DIFY_EMAIL, C.DIFY_PASSWORD)
    try:
        d.login()
        curl_chat(
            d,
            [
                {"role": "system", "content": "A"},
                {"role": "system", "content": "B"},
                {"role": "user", "content": "hi"},
            ],
            "TEST1 两条 system（期望 400）",
        )
        curl_chat(
            d,
            [
                {"role": "system", "content": "A"},
                {"role": "system", "content": ""},
                {"role": "system", "content": "C"},
                {"role": "user", "content": "hi"},
            ],
            "TEST2 含空 system（期望 400）",
        )
        curl_chat(
            d,
            [
                {"role": "system", "content": "A\n\nB\n\nC"},
                {"role": "user", "content": "hi"},
            ],
            "TEST3 合并单条 system（期望成功）",
        )
        return 0
    finally:
        d.close()


if __name__ == "__main__":
    sys.exit(main())

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""专题四 · 步骤 4 · 修改后：替换 chat.py 的 _ensure_system_first 为合并逻辑。"""
from __future__ import annotations

import sys

import _bootstrap  # noqa: F401
import _config as C
import _plugin_patch as P
from dify_api import Dify


def main() -> int:
    d = Dify(C.DIFY_EMAIL, C.DIFY_PASSWORD)
    try:
        d.login()
        chat_path = P.find_plugin_file(d, "chat.py")
        print("chat.py:", chat_path)
        content = P.read_remote_file(d, chat_path)
        new_content = P.replace_function(content, "_ensure_system_first", P.ENSURE_SYSTEM_FIRST)
        P.deploy_plugin_file(d, chat_path, new_content)
        print("已应用合并 system 补丁并重启 plugin_daemon")
        return 0
    finally:
        d.close()


if __name__ == "__main__":
    sys.exit(main())

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""专题四 · 步骤 5 · 修改后：删除 chat.py 临时调试日志块。"""
from __future__ import annotations

import sys

import _bootstrap  # noqa: F401
import _config as C
import _plugin_patch as P
from dify_api import Dify


def main() -> int:
    d = Dify(C.DIFY_EMAIL, C.DIFY_PASSWORD)
    try:
        d.login()
        chat_path = P.find_plugin_file(d, "chat.py")
        content = P.read_remote_file(d, chat_path)
        new_content = P.remove_debug_log(content)
        P.deploy_plugin_file(d, chat_path, new_content)
        print("已删除调试日志并重启 plugin_daemon")
        return 0
    finally:
        d.close()


if __name__ == "__main__":
    sys.exit(main())

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
"""专题四 · 步骤 6：Agent 公开 API streaming 模式验收（无 event: error）。"""
from __future__ import annotations

import json
import sys

import _bootstrap  # noqa: F401
import _config as C
from dify_api import Dify


def main() -> int:
    d = Dify(C.DIFY_EMAIL, C.DIFY_PASSWORD)
    try:
        d.login()
        body = {
            "inputs": {},
            "query": C.AGENT_TEST_QUERY,
            "response_mode": "streaming",
            "user": "debug-workbuddy",
        }
        remote = "/tmp/agent_stream_test.json"
        with d.sftp.open(remote, "w") as f:
            f.write(json.dumps(body, ensure_ascii=False))
        cmd = (
            "curl -s -N -m 420 -X POST %s/v1/chat-messages "
            "-H 'Authorization: Bearer %s' "
            "-H 'Content-Type: application/json' "
            "-d @%s" % (C.DIFY_BASE, C.APP_API_KEY, remote)
        )
        out, err = d.sh(cmd, t=450)
        text = out or err
        print(text[-2000:] if len(text) > 2000 else text)
        if "event: error" in text:
            print("\n[FAIL] 流式响应含 event: error")
            return 1
        if "agent_message" in text or "message" in text:
            print("\n[OK] 流式响应正常")
            return 0
        print("\n[WARN] 未检测到 agent_message，请人工核对上方输出")
        return 1
    finally:
        d.close()


if __name__ == "__main__":
    sys.exit(main())