veralayer (Python)

A payment guard for AI agents on Solana. Before your agent pays, veralayer does three things:

• Scores the recipient with Vera, using the address's on-chain history.
• Verifies the signature on that result locally.
• Applies your spending policy and returns allow, review or block.

pip install veralayer

Guard a payment

from veralayer import VeraGuard, VeraBlockedError, VeraReviewRequiredError

guard = VeraGuard(policy={
    "min_tier": "medium",
    "tier_limits_sol": {"high": 50, "medium": 5},
    "daily_limit_sol": 20,
})

try:
    guard.authorize(to=recipient, amount_sol=1.5)   # raises unless allowed; records the spend
    send_sol(recipient, 1.5)                        # your existing code
except (VeraBlockedError, VeraReviewRequiredError) as e:
    print(e.decision["findings"])

To decide without recording anything, call guard.evaluate_payment(to, amount_sol). It returns {"action", "findings", ...}.

Score an address

from veralayer import Vera

vera = Vera()
r = vera.check("AgmLJBMDCqWynYnQiPCuj9ewsNNsBJXyzoUhD9LJzN51")
r["attestation"]["score"], r["attestation"]["tier"]
vera.verify(r)   # {'valid': True, 'expired': False}, checked offline

CLI

veralayer check <address>
veralayer pay <address> 2.5 --min-tier medium --daily 20

Policy

The policy fields, defaults and finding codes are the same as in the JavaScript package, with the field names in snake_case. The policy engine is pure, so you can call evaluate_policy(outflows, recipients, spent_today_sol, policy) directly.

Trust

Results must be signed by Vera's production key, VERA_ISSUER, which is pinned in the package. A result for a different address than the one requested is rejected. NaN or negative amounts block. A policy with a typo raises ValueError. authorize is thread-safe, and release(decision) gives back the amount if the send fails.

Differences from the JavaScript package

• No transaction decoding (yet). Python agents usually build payments themselves, so the guard works on planned payments: authorize, evaluate_payment and evaluate_outflows.
• One dependency: cryptography, used for ed25519.

Docs: https://veraagent.io/docs · MIT · by VeraLayer