kora-sdk 1.2.0

Python SDK for the Kora authorization engine — deterministic spend authorization for AI agents

Kora Python SDK

Python SDK for the Kora authorization engine. Handles Ed25519 signing, nonce generation, canonical JSON serialization, idempotent retry, and offline seal verification.

Installation

pip install kora-sdk

Or install from source:

pip install -e sdk/python

Requirements: Python 3.9+, PyNaCl >= 1.5.0, requests >= 2.28.0

Quick Start

from kora import Kora

# Initialize with the secret key returned from agent creation
kora = Kora("kora_agent_sk_...")

# Authorize a spend
auth = kora.authorize(
    mandate="mandate_abc123",
    amount=50_00,        # EUR 50.00
    currency="EUR",
    vendor="aws",
    category="compute",  # required if mandate has category_allowlist
)

if auth.approved:
    print(f"Approved: {auth.decision_id}")
    print(f"Daily remaining: {auth.limits_after_approval['daily_remaining_cents']}")
else:
    print(f"Denied: {auth.reason_code}")
    print(f"Hint: {auth.denial.hint}")

Usage

Authorize a Spend

from kora import Kora

kora = Kora(
    "kora_agent_sk_...",
    base_url="http://localhost:8000",  # default
    ttl=300,          # default TTL in seconds
    max_retries=2,    # automatic idempotent retry on network error
)

result = kora.authorize(
    mandate="mandate_abc123",
    amount=50_00,
    currency="EUR",
    vendor="aws",
    category="compute",
)

Result Properties

result.approved        # bool — True if APPROVED
result.decision        # "APPROVED" or "DENIED"
result.decision_id     # UUID of the authorization decision
result.reason_code     # "OK", "DAILY_LIMIT_EXCEEDED", etc.
result.executable      # bool — True if payment can be executed
result.is_valid        # bool — True if TTL has not expired
result.is_enforced     # bool — True if enforcement_mode == "enforce"
result.enforcement_mode  # "enforce" or "log_only"

# On denial:
result.denial.hint            # Human-readable suggestion
result.denial.actionable      # Machine-readable corrective values
result.denial.failed_check    # Which pipeline step failed

# On approval:
result.limits_after_approval  # Remaining daily/monthly budget

# Evaluation trace:
result.evaluation_trace.steps        # List of pipeline step results
result.evaluation_trace.total_duration_ms  # Total evaluation time

# Notary seal:
result.notary_seal.signature    # Ed25519 signature (base64)
result.notary_seal.public_key_id
result.notary_seal.algorithm    # "Ed25519"

# Trace URL (for debugging denials):
result.trace_url  # e.g. http://localhost:8000/v1/authorizations/<id>/trace

Handle Denials

result = kora.authorize(
    mandate="mandate_abc123",
    amount=999_99,
    currency="EUR",
    vendor="aws",
)

if not result.approved:
    print(f"Denied: {result.reason_code}")
    print(f"Hint: {result.denial.hint}")

    # Machine-readable corrective values
    if result.reason_code == "DAILY_LIMIT_EXCEEDED":
        available = result.denial.actionable["available_cents"]
        print(f"Available budget: {available} cents")

    if result.reason_code == "VENDOR_NOT_ALLOWED":
        allowed = result.denial.actionable["allowed_vendors"]
        print(f"Allowed vendors: {allowed}")

    # Full trace URL for debugging
    print(f"Trace: {result.trace_url}")

Verify Notary Seal (Offline)

from base64 import b64decode

# Kora's public key (from your deployment)
kora_public_key = b64decode("...")

is_valid = kora.verify_seal(result, kora_public_key)
print(f"Seal valid: {is_valid}")

Simulation Mode

Test denial scenarios without affecting state. Requires an admin key with simulation_access=true.

result = kora.authorize(
    mandate="mandate_abc123",
    amount=100,
    currency="EUR",
    vendor="aws",
    simulate="DAILY_LIMIT_EXCEEDED",
    admin_key="kora_admin_...",
)

assert result.simulated is True
assert result.decision == "DENIED"
assert result.reason_code == "DAILY_LIMIT_EXCEEDED"
assert result.notary_seal is None  # no seal in simulation

OpenAI Function Tool Schema

Generate an OpenAI-compatible function tool definition for use with LLM agents:

tool = kora.as_tool("mandate_abc123")
# Returns:
# {
#     "type": "function",
#     "function": {
#         "name": "kora_authorize_spend",
#         "description": "Authorize a spend against a Kora mandate...",
#         "parameters": {
#             "type": "object",
#             "properties": {
#                 "amount_cents": {"type": "integer", "description": "..."},
#                 "currency": {"type": "string", "description": "..."},
#                 "vendor_id": {"type": "string", "description": "..."},
#             },
#             "required": ["amount_cents", "currency", "vendor_id"]
#         }
#     }
# }

# With category enum constraint:
tool = kora.as_tool("mandate_abc123", category_enum=["compute", "api_services"])

Use with OpenAI:

import openai

client = openai.OpenAI()
response = client.chat.completions.create(
    model="gpt-4",
    messages=[{"role": "user", "content": "Buy $50 of AWS compute"}],
    tools=[kora.as_tool("mandate_abc123")],
)

Agent Self-Correction Pattern

from kora import Kora

kora = Kora("kora_agent_sk_...")

# First attempt — too large
auth = kora.authorize(mandate="mandate_abc123", amount=999_99, currency="EUR", vendor="aws")

if not auth.approved and auth.reason_code == "DAILY_LIMIT_EXCEEDED":
    # Read the actionable hint
    available = auth.denial.actionable["available_cents"]
    print(f"Budget available: {available} cents, retrying...")

    # Retry with corrected amount
    auth = kora.authorize(mandate="mandate_abc123", amount=available, currency="EUR", vendor="aws")
    print(f"Second attempt: {auth.decision}")  # APPROVED

API Reference

Kora(key_string, base_url=None, ttl=300, max_retries=2)

Parameter	Type	Default	Description
key_string	str	required	Agent secret key (kora_agent_sk_...)
base_url	str	http://localhost:8000	Kora API base URL
ttl	int	300	Default TTL for decisions (seconds)
max_retries	int	2	Automatic retries on network error

kora.authorize(**kwargs) -> AuthorizationResult

Parameter	Type	Required	Description
mandate	str	yes	Mandate ID
amount	int	yes	Amount in cents
currency	str	yes	3-letter currency code
vendor	str	yes	Vendor identifier
category	str	no	Spending category
simulate	str	no	Force denial reason code (simulation mode)
admin_key	str	no	Admin key for simulation access

kora.verify_seal(result, public_key) -> bool

Verify the Ed25519 notary seal offline.

kora.as_tool(mandate, category_enum=None) -> dict

Generate OpenAI function tool schema.