For developers
One authorization layer for every consequential agent action.
Your agent decides what it wants to do - spend, subscribe, disclose, delegate, hire. Quattrino decides whether it is authorized, on which authority, and up to what limit. Any provider executes. Quattrino records why it was allowed and what happened - even when Quattrino never moves the money. Why not build this yourself? Because narrowing algebra, commitment classes, conserved delegation, single-use binding and evidence are the hard part - and they must never be wrong.
Quickstart · under 15 minutes · TEST/SANDBOX
Credential to first meaningful authorization.
Single-file SDKs with no dependencies (not yet on PyPI/npm), an MCP server, or plain REST. Nothing here moves real money.
1 · Sandbox account
Create a sandbox account (open signup, no invite, no card). MFA optional.
2 · Standing authority
Give an agent a standing policy (e.g. $50 per action), sandbox funds and a scoped key - in the app or with bootstrap_sandbox.py.
3 · Authorize
authorize(amount 19.99, task under $20) -> AUTHORIZED; 20.01 -> DENIED. Handle the four answers the same way, always.
4 · Act · prove
Binding authorization -> you execute anywhere -> record the outcome -> explain in plain language.
The first workflow
Six steps. One question: is this authorized?
You never need to understand payment rails to ask. Execution is optional and pluggable.
- 1
Connect agent
Pair an agent and issue it a scoped credential. It never sees a card, a login or a secret.
- 2
Call authorize()
State the action, the amount, the counterparty, the purpose and any structured task constraints.
- 3
Receive a decision
AUTHORIZED, APPROVAL_REQUIRED, DENIED or NEEDS_INFORMATION - with the effective maximum and why.
- 4
Execute (optional)
Use a Quattrino execution adapter when one exists, or execute with your own provider.
- 5
Record outcome
Tell Quattrino what actually happened. Deviations from the authorized terms are flagged.
- 6
Explain
Every authorization answers who, on whose behalf, why, what narrowed it and what happened.
Quattrino may infer meaning. It must never infer consequential permission.
Vague instruction in. Safe progress out. One precise question, only when it matters.
compile_intent turns what the human said into an amendable AuthorityEnvelope. Research proceeds immediately; hiring, paying, subscribing and sharing data wait for authority that exists - or for the latest safe question.
# Phase 30: vague human intent -> safe partial progress, no invented authority
c = q.compile_intent("Find someone who can fix the embossing machine.")
c["authorized_now"] # ["research_and_compare", "contact_counterparties"]
c["not_yet_authorized"] # ["hire_supplier_or_agent", "start_subscription_or_account", ...]
env = c["envelope"]["envelope_id"]
# research is always allowed - no question asked yet
q.authorize(envelope_id=env, action_class="NON_CONSEQUENTIAL_RESEARCH", purpose="find suppliers").decision # AUTHORIZED
# the consequence point: a quote arrives. Quattrino asks ONE precise question, now.
r = q.authorize(envelope_id=env, action_type="hire_agent", merchant="Repair Co", amount_minor=32700,
purpose="repair", commitment="CONTRACT")
r.decision # NEEDS_INFORMATION (hiring authority + ceiling missing)
r.question["question"] # "May the agent hire supplier or agent (with Repair Co for $327.00) for this task?"
r.missing_authority # [{dimension: "purpose.allowed_action_classes", ...}, {dimension: "money...", ...}]
# a $9.99/month offer can never pass as a $20 one-time purchase
q.authorize(envelope_id=env_one_time, merchant="SaaSCo", amount_minor=999, purpose="software",
commitment="SUBSCRIPTION").decision # DENIED (commitment_prohibited)Every envelope version is immutable with provenance. Agents may only narrow; owners widen - bounded by the standing policy. Outcomes are checked for amount, counterparty, commitment class, data disclosed, delegation and time.
result = quattrino.authorize({...})
Standing $50. Task says under $20. Effective: $20.
A task instruction may narrow standing authority but can never expand it. Ambiguity returns NEEDS_INFORMATION, never more authority.
from quattrino import Quattrino
q = Quattrino(api_key="qtrn_sk_...") # the agent's scoped credential
result = q.authorize(
amount_minor=1899, merchant="Amazon", purpose="USB-C cable for the office",
task={"max_amount_minor": 2000, "categories": ["electronics"],
"prohibited_side_effects": ["subscription"]},
)
result.decision # AUTHORIZED
result.effective_maximum_minor # 2000 <- standing $50 narrowed to $20 by the task
auth = q.authorize_binding(amount_minor=1899, merchant="Amazon", purpose="USB-C cable")
if auth.decision == "AUTHORIZED":
if auth.execution_package["execution_mode"] == "quattrino":
q.execute(auth) # certified adapter
else:
# you execute with your own provider, then attest
q.record_outcome(auth.authorization_id, success=True,
provider="amazon", provider_reference="114-2233",
actual_amount_minor=1899)
print(q.explain(auth.authorization_id)["plain_language"])SDKs are thin wrappers over the REST contract and embed no policy logic. Source: /sdk/python, /sdk/typescript (not yet published).
Decisions
Four answers. Always deterministic. Always explainable.
AUTHORIZED
Within the effective authority. In binding mode a portable EconomicAuthorization is issued: it expires, can be revoked and is consumed exactly once.
APPROVAL_REQUIRED
A human must approve: above the autonomous maximum, a policy rule, a delegated requirement or an owner-gated disclosure. The owner decides in Approvals.
DENIED
Outside the effective authority, blocked by policy, or the task constraints are violated. Nothing is issued.
NEEDS_INFORMATION
Ambiguous or missing terms (amount, merchant, purpose, unknown constraint). Ambiguity never expands authority.
One canonical pipeline
What developers work with
Authorize · Policies · Delegation · Approvals · Evidence · Execution adapters
Authorize
One endpoint, two modes (dry_run / binding), four decisions. Works even when Quattrino never moves the money.
Standing authority (policies)
Deterministic ceilings, budgets, merchants, categories, recurrence and approval thresholds the owner sets once.
Delegation
Human -> agent -> sub-agent lineage. A child can never exceed its parent; issuance is conserved; every hop is revocable.
Approvals
When a decision needs a human, it lands in one inbox - for Quattrino-executed and authorize-only actions alike.
Evidence
Every authorization is explainable and hashed: material terms, pipeline, outcome and mismatch flags.
Execution adapters
Certified rails underneath the control plane: Stripe SPT merchants and Quattrino Credits. Optional.
Advanced
Execution adapters (optional)
Capabilities underneath the control plane. You only meet them if you ask Quattrino to execute.
Developer preview · sandbox only. Live payments, mainnet and MPP production are OFF platform-wide. Authorization usage is metered in neutral Authorization Units; authorization pricing is not activated.