Sardis — Payment OS for AI Agents

AI agents can reason, but they cannot be trusted with money. Sardis is how they earn that trust.

Sardis provides complete payment infrastructure for AI agents: non-custodial MPC wallets (Turnkey-backed), natural language spending policies, stablecoin transfers with automatic policy enforcement, virtual card issuance, and full audit trails with on-chain anchoring.

Setup

export SARDIS_API_KEY="sk_your_key_here"
export SARDIS_API_URL="https://api.sardis.sh"   # optional, defaults to production

Get your API key at https://app.sardis.sh or via the API:

curl -X POST https://api.sardis.sh/api/v2/auth/signup \
  -H "Content-Type: application/json" \
  -d '{"email": "you@example.com", "password": "your-password"}'

Security Requirements

CRITICAL — ALWAYS ENFORCE:

• ALWAYS check spending policy before payment execution
• NEVER bypass approval flows for transactions
• NEVER hardcode wallet addresses or private keys
• ALWAYS log transaction attempts for audit trail
• ALWAYS verify recipient address format before sending
• FAIL CLOSED on policy violations (deny by default)
• Use X-API-Key header for authentication on every request

API Reference

Base URL: https://api.sardis.sh

All endpoints require the X-API-Key header.

1. Create Agent + Wallet

Provision an agent identity with an MPC wallet in one call.

curl -X POST https://api.sardis.sh/api/v2/agents \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "name": "my-agent",
    "description": "Payment agent for OpenAI billing"
  }'

Response:

{
  "agent_id": "agt_abc123",
  "name": "my-agent",
  "wallet_id": "wal_xyz789",
  "addresses": {"base": "0x...", "tempo": "0x..."},
  "kya_tier": "standard",
  "created_at": "2026-03-26T12:00:00Z"
}

Then attach a dedicated wallet if needed:

curl -X POST https://api.sardis.sh/api/v2/agents/agt_abc123/wallet \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"chain": "base", "provider": "turnkey"}'

2. Send Payment

Unified payment endpoint with automatic policy enforcement, chain routing, and FX.

curl -X POST https://api.sardis.sh/api/v2/pay \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "openai.com",
    "amount": "25.00",
    "currency": "USDC",
    "chain": "base"
  }'

Response:

{
  "status": "completed",
  "tx_hash": "0xabc...def",
  "amount": "25.00",
  "currency": "USDC",
  "chain": "base",
  "policy_result": {"allowed": true, "checks_passed": ["daily_limit", "merchant_allowlist"]},
  "route": {"chain": "base", "provider": "alchemy", "gas_estimate": "0.0012"}
}

Omit chain to let Sardis auto-route to the cheapest chain:

curl -X POST https://api.sardis.sh/api/v2/pay \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"to": "anthropic.com", "amount": "100.00", "currency": "USDC"}'

3. Check Policy (Dry Run)

Pre-flight check whether a payment would be allowed by current policies.

curl -X POST https://api.sardis.sh/api/v2/policies/check \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agent_id": "agt_abc123",
    "amount": "50.00",
    "currency": "USDC",
    "merchant": "aws.amazon.com"
  }'

Response:

{
  "allowed": true,
  "reason": "All policy checks passed",
  "checks_passed": ["daily_limit", "per_tx_limit", "merchant_allowlist"],
  "checks_failed": [],
  "remaining_daily_limit": "450.00"
}

4. Set Policy (Natural Language)

Define spending rules in plain English. Sardis parses them into enforceable constraints.

curl -X POST https://api.sardis.sh/api/v2/policies/apply \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "agent_id": "agt_abc123",
    "natural_language": "Max $500 per day. Only allow OpenAI and Anthropic. No transactions over $200."
  }'

Response:

{
  "policy_id": "pol_def456",
  "agent_id": "agt_abc123",
  "parsed_rules": [
    {"type": "daily_limit", "value": "500.00", "currency": "USD"},
    {"type": "merchant_allowlist", "merchants": ["openai.com", "anthropic.com"]},
    {"type": "per_transaction_limit", "value": "200.00", "currency": "USD"}
  ],
  "version": 3,
  "applied_at": "2026-03-26T12:05:00Z"
}

You can also preview before applying:

curl -X POST https://api.sardis.sh/api/v2/policies/preview \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"agent_id": "agt_abc123", "natural_language": "Block all payments over $1000"}'

5. Check Balance

# Single-chain balance
curl -X GET "https://api.sardis.sh/api/v2/wallets/wal_xyz789/balance?chain=base" \
  -H "X-API-Key: $SARDIS_API_KEY"

Response:

{
  "wallet_id": "wal_xyz789",
  "chain": "base",
  "balance": "1250.00",
  "currency": "USDC",
  "updated_at": "2026-03-26T12:00:00Z"
}

# Multi-chain balances (all chains at once)
curl -X GET "https://api.sardis.sh/api/v2/wallets/wal_xyz789/balances" \
  -H "X-API-Key: $SARDIS_API_KEY"

6. Issue Virtual Card

Issue a stablecoin-funded virtual Visa card for real-world purchases.

curl -X POST https://api.sardis.sh/api/v2/cards/virtual/issue \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": "25.00",
    "card_type": "single_use"
  }'

Response:

{
  "card_id": "crd_abc123",
  "card_number": "4242424242424242",
  "cvv": "123",
  "expiry": "12/27",
  "amount": "25.00",
  "currency": "USD",
  "card_type": "single_use",
  "status": "active"
}

7. Wallet Transfer (Direct)

Transfer stablecoins from a specific wallet (with automatic policy enforcement).

curl -X POST https://api.sardis.sh/api/v2/wallets/wal_xyz789/transfer \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "to": "0x742d35Cc6634C0532925a3b844Bc9e7595f0bEb",
    "amount": "50.00",
    "token": "USDC",
    "chain": "base",
    "agent_id": "agt_abc123"
  }'

Response:

{
  "tx_hash": "0xdef...abc",
  "status": "confirmed",
  "amount": "50.00",
  "token": "USDC",
  "chain": "base",
  "block_number": 12345678
}

8. Transaction Status

curl -X GET "https://api.sardis.sh/api/v2/transactions/status/0xabc...def" \
  -H "X-API-Key: $SARDIS_API_KEY"

9. Agent Spending Analytics

curl -X GET "https://api.sardis.sh/api/v2/agents/agt_abc123/spending" \
  -H "X-API-Key: $SARDIS_API_KEY"

10. Create Spending Mandate

Spending mandates define scoped, time-limited authority over funds.

curl -X POST https://api.sardis.sh/api/v2/mandates \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "wallet_id": "wal_xyz789",
    "agent_id": "agt_abc123",
    "max_amount": "1000.00",
    "currency": "USDC",
    "expires_at": "2026-04-01T00:00:00Z",
    "merchant_allowlist": ["openai.com", "anthropic.com"]
  }'

Complete Onboarding Flow

# 1. Create agent (auto-provisions wallet)
AGENT=$(curl -s -X POST https://api.sardis.sh/api/v2/agents \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"name": "billing-agent", "description": "Handles API billing"}')
AGENT_ID=$(echo $AGENT | jq -r '.agent_id')
WALLET_ID=$(echo $AGENT | jq -r '.wallet_id')
echo "Agent: $AGENT_ID, Wallet: $WALLET_ID"

# 2. Set spending policy
curl -s -X POST https://api.sardis.sh/api/v2/policies/apply \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d "{\"agent_id\": \"$AGENT_ID\", \"natural_language\": \"Max \$100 per transaction, \$500 per day. Only OpenAI and Anthropic.\"}"

# 3. Check balance
curl -s -X GET "https://api.sardis.sh/api/v2/wallets/$WALLET_ID/balances" \
  -H "X-API-Key: $SARDIS_API_KEY" | jq '.'

# 4. Dry-run policy check
curl -s -X POST https://api.sardis.sh/api/v2/policies/check \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d "{\"agent_id\": \"$AGENT_ID\", \"amount\": \"25.00\", \"currency\": \"USDC\", \"merchant\": \"openai.com\"}"

# 5. Execute payment (policy auto-enforced)
curl -s -X POST https://api.sardis.sh/api/v2/pay \
  -H "X-API-Key: $SARDIS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"to": "openai.com", "amount": "25.00", "currency": "USDC", "chain": "base"}'

Error Handling

Always check response status codes:

Example error (policy violation):

{
  "error": {
    "code": "POLICY_VIOLATION",
    "message": "Daily spending limit of $500 exceeded. Current: $475, Requested: $50",
    "details": {
      "limit": "500.00",
      "current": "475.00",
      "requested": "50.00"
    }
  }
}

Supported Chains & Tokens

Related Skills

• sardis-balance — Read-only balance checking and analytics
• sardis-policy — Natural language spending policy management
• sardis-cards — Virtual card issuance and management
• sardis-guardrails — Circuit breaker and kill switch controls
• sardis-identity — Agent identity with TAP verification
• sardis-escrow — Smart contract escrow for agent-to-agent payments
• sardis-tempo-pay — MPP-native payments on Tempo mainnet

Links

• Website: https://sardis.sh
• Dashboard: https://app.sardis.sh
• API Docs: https://api.sardis.sh/api/v2/docs
• GitHub: https://github.com/EfeDurmaz16/sardis
• Support: support@sardis.sh