Policies

A policy is the deterministic set of constraints inside a mandate. Your backend translates end-user intent into this structure. Attesso does not evaluate prompts, scripts, or natural language.

{
  "version": "1",
  "action": "flight.book",
  "constraints": [
    { "path": "attributes.origin", "operator": "eq", "value": "AMS" },
    { "path": "attributes.destination", "operator": "in", "values": ["LIS", "JFK"] },
    {
      "path": "attributes.departureDate",
      "operator": "date_range",
      "on_or_after": "2026-08-01",
      "on_or_before": "2026-08-14"
    },
    { "path": "payment.amount", "operator": "max", "value": 15000 },
    { "path": "payment.currency", "operator": "eq", "value": "EUR" }
  ]
}

Operators

Operator	Behavior
`eq`	Exact JSON type and value equality
`in`	Exact membership in an ordered set of allowed values
`max`	Inclusive integer maximum
`date_range`	Inclusive range for full `YYYY-MM-DD` dates

Every constraint is combined with logical AND. Exactly one constraint may target each path.

Exact evaluation

Policy v1 intentionally has no coercion, case folding, wildcard, regular expression, locale processing, timezone conversion, floating-point input, or Unicode normalization.

A present value that violates a constraint produces DENY.
Missing, incorrectly typed, or unsupported evaluable data produces INDETERMINATE.
Both results are non-allow decisions and create no reservation.
A different valid action name produces DENY without evaluating constraints from the other action domain.

Payment authority

Payment authority is explicit and indivisible. A policy either:

Contains no payment paths and can only authorize actions without payment, or
Contains exactly one positive-integer payment.amount max and exactly one uppercase three-letter payment.currency eq

Amounts use integer minor units. For EUR, 14200 means EUR 142.00.

Canonical digest

Attesso canonicalizes the validated policy with RFC 8785 and binds a domain-separated SHA-256 policy_digest to the mandate, approval, and evidence.

preimage = UTF8("attesso:policy:v1\n") || canonical_policy_bytes
digest   = "sha256:" || lowercase_hex(SHA-256(preimage))

Preserve constraint and in value order. Array order is digest-significant even when it does not change evaluation semantics.

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Core concepts

Guides

Developer reference

Operators

Exact evaluation

Payment authority

Canonical digest

​Operators

​Exact evaluation

​Payment authority

​Canonical digest

Operators

Exact evaluation

Payment authority

Canonical digest