tacet

Official Python client for the Tacet API.

Install

pip install tacet
# or
uv add tacet

Quickstart

from tacet import Tacet, choice, score, noul

client = Tacet(api_key="tacet_sk_...")  # or set TACET_API_KEY

result = client.decide(
    state="Customer says their export has been stuck at 'processing' for two days.",
    questions={
        "routing_team": choice(
            "Which team should own this ticket?",
            {"billing": "Payment or invoicing issues", "support": "Product or account issues"},
        ),
        "urgency": score(
            "How urgent is this ticket?",
            ["low", "medium", "high", "critical"],
        ),
        "needs_human": noul("Does this ticket need a human to step in?"),
    },
)

print(result.answers["routing_team"].choice)
print(result.answers["urgency"].score)
print(result.answers["needs_human"].noul)
print(result.usage.input_tokens)

An AsyncTacet client with the same methods, awaited, is available for async code.

Question types

• choice: pick one option out of a named set. criteria maps option names to descriptions. The answer carries choice, probabilities (one per option), and confidence.
• score: an expected level over an ordered list of levels. criteria is that list. The answer carries score, probabilities (one per level index), and confidence.
• noul: yes or no. noul is the probability of yes, from 0 to 1, and an optional criteria object says what "true" and "false" mean. The answer carries noul and confidence, no probabilities.

The choice, score, and noul helpers build the question dict for you; you can also pass the dict shape directly.

Errors and retries

Every non-2xx response raises a subclass of TacetError, which carries status, code, error_type, param, request_id, and message:

• AuthenticationError: 401 (missing, invalid, or revoked API key)
• InsufficientCreditError: 402 (out of credit)
• RateLimitError: 429, also carries retry_after seconds
• InvalidRequestError: 400/404/413 (bad request, unknown model, state too large, etc.)
• APIError: 5xx
• APIConnectionError: the request failed before a response came back

The client retries 429s (honoring the Retry-After header) and 500/502/503/504 responses and connection failures, with exponential backoff and jitter, up to max_retries times (default 2). Other 4xx errors fail immediately and are never retried.

Idle starts

If the API hasn't been called in a while, the first request after that idle period can take tens of seconds while it starts back up. The default timeout (90 seconds) accounts for this; don't lower it unless you know your traffic is steady.

Pricing

$0.042 per 1M input tokens, and output is free. Details are in the API docs.