Decision Model System One API - Alibaba Cloud Model Studio

Call POST /compatible-mode/v1/systemone to use the Bailian decision model (decision-model-preview), which returns classification, scoring, and yes/no decisions with full probability distributions and confidence in a single forward pass, without generating text. Suitable for high-frequency structured decisions such as ticket routing, content moderation, agent routing, and result verification.

Prerequisites

You have created an API Key and set it as the environment variable DASHSCOPE_API_KEY. For more information, see Configure an API key in environment variables.

Request

Protocol: TypeSafe System One (POST /compatible-mode/v1/systemone)

A single request carries the business state and several typed questions (choice / noul / score). The model returns the decision result and probability distribution for each question in one forward pass, with choice and score additionally returning confidence, and does not generate text, so latency and cost are independent of output length.

Endpoint

Replace {WorkspaceId} with your workspace ID. See Regions and endpoints.

Region	Endpoint
Singapore	`https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode/v1/systemone`
China (Beijing)	`https://{WorkspaceId}.cn-beijing.maas.aliyuncs.com/compatible-mode/v1/systemone`

Request Parameters

Content-Type · String · Header · Required

Request type: application/json.

Authorization · String · Header · Required

API key, in the format: Bearer $DASHSCOPE_API_KEY.

model · String · Body · Required

Model name: decision-model-preview.

state · String / Object / Array · Body · Required

The business state to make decisions on: ticket text, a conversation, or a structured object (objects are serialized before being sent to the model).

questions · Object · Body · Required

A map of questions. The key is a caller-defined question id; the value is a question object with the following fields.

questions properties

type · String · Required

Question type:

choice: single choice
noul: yes/no
score: ordinal scale

instructions · String · Optional

Question description or judgment criteria.

criteria · Object / Array · Depends on type

choice: a map of option name → option description (1–255 items; providing all options and an other fallback is recommended).
noul: optional {"true":…, "false":…} descriptions.
score: an array of level descriptions from low to high (2–10 levels; 3–7 clearly distinguishable levels recommended).

Limits and recommendations

No hard limit on the number of questions (recommended: ≤ 16; latency grows near-linearly with the number of questions).
choice options: ≤ 255.
score levels: 2–255 (3–7 recommended).
Context: maximum 65536 tokens; overlong state is rejected or truncated.

Request Examples

The Python examples use the TypeSafe SDK (typesafe-sdk) with base_url pointing to the Bailian gateway. The SDK automatically appends /v1/systemone and parses the response. Install: pip install typesafe-sdk.

Ticket routing

A single request handles three decisions at once: team assignment (choice), escalation (noul), and severity (score). The example below uses the Singapore region.

curl

curl -sS -X POST https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode/v1/systemone \
  -H "Authorization: Bearer $DASHSCOPE_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "decision-model-preview",
    "state": {"ticket_id": "T-1001", "content": "More than 24 hours after payment, the order has not been credited. The user cannot continue using core services and demands immediate handling."},
    "questions": {
      "department": {"type": "choice", "instructions": "Which team should handle this?",
                     "criteria": {"billing": "Payment, refund, and billing issues", "technical": "Product failure and integration issues"}},
      "escalate":   {"type": "noul",  "instructions": "Should on-call staff be notified immediately?"},
      "severity":   {"type": "score", "instructions": "How severe is this issue?",
                     "criteria": ["Minor issue, no impact on functionality", "Some functionality affected, but a workaround exists",
                                  "Core functionality unavailable, no workaround", "Severe business or security impact"]}
    }
  }'

Python

import os
from typesafe_sdk import TypeSafeClient

client = TypeSafeClient(
    api_key=os.environ["DASHSCOPE_API_KEY"],
    base_url="https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode",
)

result = client.system_one(
    model="decision-model-preview",
    state={"ticket_id": "T-1001", "content": "More than 24 hours after payment, the order has not been credited."},
    questions={
        "department": {"type": "choice", "instructions": "Which team should handle this?",
                       "criteria": {"billing": "Payment, refund, and billing issues", "technical": "Product failure and integration issues"}},
        "escalate": {"type": "noul", "instructions": "Should on-call staff be notified immediately?"},
        "severity": {"type": "score", "instructions": "How severe is this issue?",
                     "criteria": ["Minor issue, no impact on functionality", "Some functionality affected, but a workaround exists",
                                  "Core functionality unavailable, no workaround", "Severe business or security impact"]},
    },
)

print(result.answers["department"])   # choice, confidence, probabilities
print(result.answers["escalate"])     # noul P(yes)
print(result.answers["severity"])     # score, legend, probabilities

Yes/no decision

A noul question returns P(yes), where 0 = no and 1 = yes. The example below uses the Singapore region.

curl

curl -sS -X POST https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode/v1/systemone \
  -H "Authorization: Bearer $DASHSCOPE_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "decision-model-preview",
    "state": "Is this comment asking for a refund?",
    "questions": {
      "refund": {"type": "noul", "instructions": "Is the user asking for a refund?"}
    }
  }'

Python

import os
from typesafe_sdk import TypeSafeClient

client = TypeSafeClient(
    api_key=os.environ["DASHSCOPE_API_KEY"],
    base_url="https://{WorkspaceId}.ap-southeast-1.maas.aliyuncs.com/compatible-mode",
)

result = client.system_one(
    model="decision-model-preview",
    state="Is this comment asking for a refund?",
    questions={"refund": {"type": "noul", "instructions": "Is the user asking for a refund?"}},
)

print(result.answers["refund"])   # noul P(yes)

Response Parameters

model · String

Model name echoed back.

request_id · String

Request ID, for troubleshooting.

answers · Object

A map of answers. The key corresponds to the question id in the request; the value is an answer object with the following fields.

answers properties

type · String

Matches the question type (choice / noul / score).

choice · String

For choice: the selected option name.

noul · Float

For noul: P(yes), where 0 = no and 1 = yes.

score · Float

For score: the probability-weighted expectation of the level index, which can fall between two levels (e.g. 1.43).

probabilities · Object

The probability of each option / level (sums to 1).

confidence · Float

The confidence of the answer (returned for choice / score).

legend · Object

For score: a map of level index → level description.

usage · Object

Metering information:

input_tokens (Integer): number of input tokens.

latency_ms · Float

Server-side latency (milliseconds).

Response Example

The following is the response for the ticket routing example (abbreviated). Probabilities and confidence depend on the actual result.

{
  "model": "decision-model-preview",
  "request_id": "7b986c65-b223-9341-b5f0-b988e27ecaac",
  "answers": {
    "department": {
      "type": "choice",
      "choice": "billing",
      "confidence": 0.88,
      "probabilities": {"billing": 0.94, "technical": 0.06}
    },
    "escalate": {
      "type": "noul",
      "noul": 0.99
    },
    "severity": {
      "type": "score",
      "score": 2.25,
      "confidence": 0.91,
      "legend": {
        "0": "Minor issue, no impact on functionality",
        "1": "Some functionality affected, but a workaround exists",
        "2": "Core functionality unavailable, no workaround",
        "3": "Severe business or security impact"
      },
      "probabilities": {"0": 0.0, "1": 0.01, "2": 0.73, "3": 0.26}
    }
  },
  "usage": {"input_tokens": 125},
  "latency_ms": 52.9
}

Error Codes

If the call fails, an error message is returned. For more error codes and solutions, see Error messages.