alibabacloud-cadt-arch-draw

CADT Architecture Diagram Drawing

Submit a product/resource description → CADT AI agent creates the architecture (nodes, connections, validation, layout) and returns a Markdown summary.

Prerequisites

aliyun version              # >= 3.3.3
aliyun configure list       # valid profile exists

If not met, see references/related-commands.md § Installation.

Security: NEVER read/echo AK/SK values, NEVER ask user to input credentials in conversation.

Flow

Step 1: Submit Drawing Request (SendMessage)

aliyun bpstudio execute-operation-sync \
  --service-type ai_agent \
  --operation SendMessage \
  --region cn-hangzhou \
  --user-agent "AlibabaCloud-Agent-Skills/alibabacloud-cadt-arch-draw/{SESSION_ID}" \
  --attributes '{
    "prompt": "一台 Web ECS + 一台 MySQL RDS + 一台 SLB，部署在同一个 VPC 内"
  }'

prompt (required): product/resource list — be specific about products, quantities, and relationships
sessionId (optional): omit for new session; pass to iterate on existing architecture
scene (optional): reserved for future drawing modes — currently no available values, omit

Session reuse (MANDATORY): If the user provides a sessionId (e.g. "sessionId is 1001", "modify based on the previous architecture", "continue modifying the diagram from just now"), you MUST pass that exact sessionId in this SendMessage call to iterate on the existing CADT session. NEVER start a fresh session and NEVER regenerate the architecture locally. A new execution environment does NOT lose the session — the session lives on the CADT backend, keyed by sessionId; just pass it through the CLI.

Response:

{
  "Code": 200,
  "Data": {
    "Status": "SUCCESS",
    "Arguments": { "triggered": true, "sessionId": 1001, "requestId": "xxx-xxx" }
  }
}

Architecture generation typically takes 30–120 seconds depending on complexity.

Step 2: Poll for Result (ListMessage)

aliyun bpstudio execute-operation-sync \
  --service-type ai_agent \
  --operation ListMessage \
  --region cn-hangzhou \
  --user-agent "AlibabaCloud-Agent-Skills/alibabacloud-cadt-arch-draw/{SESSION_ID}" \
  --attributes '{"sessionId": 1001}'

Response structure:

{
  "Data": {
    "Status": "SUCCESS",
    "Arguments": {
      "hasMore": false,
      "hasNext": false,
      "lastMessageId": 5002,
      "messageList": [
        {
          "messageId": 5001,
          "sessionId": 1001,
          "senderType": "customer",
          "senderId": "120012345678****",
          "content": "...",
          "status": "done",
          "messageSendTime": 1700000000000
        },
        {
          "messageId": 5002,
          "sessionId": 1001,
          "senderType": "robot",
          "senderId": "robot",
          "content": "...Markdown architecture summary...",
          "status": "done",
          "prompt": "...",
          "messageSendTime": 1700000090000
        }
      ]
    }
  }
}

Polling logic:

Find the last message where senderType == "robot"
If its status == "ongoing" → wait 5s, poll again
If its status == "done" → proceed to Step 3
If messageList is empty / has no robot message → keep polling with the same sessionId (this alone is NOT a reason to switch sessions)
Max poll: 30 times (~150s), then timeout → stop and report to the user

On timeout or persistently empty response: NEVER create a new session as a workaround. Report to the user that session {sessionId} returned no response (it may not exist, may have expired, or may belong to another environment) and ask how to proceed. Creating a new session without the user's explicit consent violates Hard Rule #6.

Multi-turn: The robot may ask clarifying questions (e.g., "Which region is it deployed in?") instead of directly drawing. In that case, status == "done" but content is a question — present it to the user, collect their reply, and call SendMessage again with the same sessionId.

Invalid input: Nonexistent products/regions (e.g. a made-up product name or a fake region like cn-nowhere) do NOT return FAILURE — the robot replies with a clarifying question (Case B) pointing out what it cannot recognize. Relay that clarification faithfully; NEVER fabricate a successful architecture.

Step 3: Deliver Result

When the robot's last message has status == "done", check its content:

Case A — Architecture complete (content contains resource table / topology / validation):

Present the robot's Markdown content to the user
Inform user the architecture has been created in CADT and can be viewed/edited at CADT Console
Offer to continue modifying (reuse the same sessionId)

Case B — Clarifying question (content is a question asking for more info):

Present the question to the user
Collect user's reply
Call SendMessage again with the same sessionId and the reply as prompt
Go back to Step 2

Prompt Tips

Style	Example
Simple	"one ECS + one RDS"
With roles	"Web ECS + MySQL RDS + SLB load balancing"
With topology	"two ECS instances in a VPC, exposed externally through SLB, followed by Redis and PolarDB"
Multi-AZ	"one ECS instance in each of two availability zones, sharing RDS and Redis"
Constraints	"high-availability architecture: ALB + 2 ECS instances across AZs, RDS active-standby"

Error Handling

Status	Action
`SUCCESS`	Proceed with Arguments data — never retry
`FAILURE` (business error, e.g. permission/quota/parameter error)	Show `Message` to user and stop — do NOT retry
`FAILURE` + "Failed to invoke" in Message (backend service unavailable)	Transient backend outage only — wait 30s and retry once; if it still fails, report to user
Robot message `status` stays `ongoing` beyond 150s	Inform user of timeout — keep the same sessionId, do NOT create a new session
`messageList` empty / no robot message after max polls	Report to user that session `{sessionId}` returned no response — never start a new session without user consent

Retry policy: Retry is a conditional edge-case that applies only to the Failed to invoke backend-unavailable FAILURE. A SUCCESS response or any business-error FAILURE MUST NOT trigger any retry.

Observability

All aliyun CLI calls in this skill MUST include --user-agent for tracing.

UA template (placeholder form):

--user-agent AlibabaCloud-Agent-Skills/alibabacloud-cadt-arch-draw/{SESSION_ID}

UA actual example (runtime form):

--user-agent AlibabaCloud-Agent-Skills/alibabacloud-cadt-arch-draw/a1b2c3d4e5f6a7b8c9d0e1f2a3b4c5d6

Session-id rules:

If env var SKILL_SESSION_ID is set, use its value directly
Otherwise, generate a 32-char lowercase hex string (uuid4().hex) once at skill session start
Reuse the same session-id across all CLI calls within one user interaction session

Hard Rules

All calls via aliyun bpstudio execute-operation-sync — no raw HTTP
uid is auto-injected by gateway — never pass in attributes
Poll by checking robot message status, not a top-level ongoing field
Present the robot's Markdown content faithfully — do not fabricate results
NEVER generate architecture diagrams locally (no local .md/.html/image files, no drawing from scratch). The architecture is ALWAYS produced by the CADT backend via aliyun CLI — your only job is to call the API and relay its output.
When the user provides a sessionId, you MUST reuse it by passing it to SendMessage — never create a new session or start over. A new/restarted execution environment does NOT invalidate the session; it persists on the CADT backend keyed by sessionId. Even on polling timeout or an empty response, do NOT switch to a new session — stop and report to the user; only the user may authorize a new session.
This skill is architecture-creation only — no resource provisioning or deployment
Every aliyun call MUST carry --user-agent as specified in Observability section