Aplomb API

About Aplomb

Answers yes or no, choice, score, and tool questions about text, JSON, images, video, and audio, reads up to 1M tokens, and can say when the answer is not there.

Send a state and typed questions to POST /v1/decisions. Answers are probabilities with a confidence value; no text is generated. Billed on input tokens only.

Also known as EmpirioLabs Aplomb

Aplomb specs

Model ID

aplomb

Author

EmpirioLabs

Category

Decision Models

Released

Sep 29, 2026

Context window

1M tokens

Input

TextImageVideoAudio

Output

Decision

Endpoints

POST/v1/decisions

Alternate model IDs

empiriolabs/aplomb

Aplomb API pricing

Live pay-as-you-go rates from the EmpirioLabs catalog. You are billed only for what you use, with no monthly minimum.

How to call the Aplomb API

Aplomb answers questions about your content through POST /v1/decisions. Send the content in state and your questions in questions with the model id aplomb. Each answer returns probabilities and a confidence value instead of generated text. Get an API key from the EmpirioLabs dashboard.

curl https://api.empiriolabs.ai/v1/decisions \
  -H "Authorization: Bearer $EMPIRIOLABS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "aplomb",
    "state": "I was charged twice for my subscription this month. Please refund the duplicate charge today.",
    "questions": {
      "is_urgent": {"type": "noul", "instructions": "Does the customer need a resolution today?"},
      "department": {
        "type": "choice",
        "instructions": "Which team should handle this message?",
        "criteria": {"billing": null, "technical": null, "sales": null}
      }
    }
  }'

import requests

response = requests.post(
    "https://api.empiriolabs.ai/v1/decisions",
    headers={"Authorization": "Bearer YOUR_EMPIRIOLABS_API_KEY"},
    json={
        "model": "aplomb",
        "state": "I was charged twice for my subscription this month. Please refund the duplicate charge today.",
        "questions": {
            "is_urgent": {"type": "noul", "instructions": "Does the customer need a resolution today?"},
            "department": {
                "type": "choice",
                "instructions": "Which team should handle this message?",
                "criteria": {"billing": None, "technical": None, "sales": None},
            },
        },
    },
)
answers = response.json()["answers"]
print(answers["is_urgent"]["noul"], answers["department"]["choice"])

Good to know

Requests

Send content in state (a string, a JSON object, or an array) and 1 to 128 questions in questions to POST /v1/decisions. Each question is answered on its own, with probabilities and a confidence value. No text is generated.

Question types

• noul: yes or no, answered with the probability of yes.
• choice: one of 2 to 255 options, answered with the chosen option and the full distribution.
• score: 2 to 10 ordered levels, answered with the expected level and the distribution.
• tool: which of 1 to 254 function tools to call, with distributions over its enum and boolean arguments.

Not in the state

Add "abstain": true to a noul, choice or score question to let the model say the state does not contain the answer. The answer then includes abstain, the probability of that outcome, and the rest of the answer assumes the state does contain it.

Limits

• The state plus the longest question: up to 1,000,000 tokens.
• At most 512 evaluated questions per request. A tool question counts as one plus one per enum or boolean argument.
• Media: up to 16 images (20 MB each), 8 audio clips (25 MB and 10 minutes each) and 4 videos (100 MB and 10 minutes each), as public HTTPS URLs or inline base64.

Billing

Input tokens only: the state once per request, each question's own text, and each media item's tokens. Output is always zero.

Aplomb API: common questions

How much does the Aplomb API cost?

On EmpirioLabs, Aplomb is billed pay as you go. The live rate card on this page always matches what the API charges.

What is the context window of Aplomb?

Aplomb supports a 1M-token context window.

Which endpoint does Aplomb use?

Aplomb is served through POST /v1/decisions on api.empiriolabs.ai with standard bearer-token authentication.

Can I try Aplomb in the browser before integrating?

Yes. The EmpirioLabs playground runs Aplomb in the browser with the same parameters the API exposes, so you can test prompts before writing code.

How do I get a Aplomb API key?

Create an EmpirioLabs account, then generate a key under API Keys in the dashboard. Billing is pay-as-you-go credits, so you only pay for the requests you make.