Balance Locking

For operations where you don’t know the final cost upfront — like AI completions, batch processing, or long-running jobs — you can reserve balance before the work starts, then finalize the reservation when it’s done. This is a three-step flow:

Check with lock — atomically check access and hold balance
Do work — run your operation
Finalize — confirm the deduction, adjust it, or release the hold

Step 1: Check with lock

Pass the lock parameter to the check endpoint. This atomically checks if the customer has enough balance and reserves it in a single call.

const response = await autumn.check({
  customerId: "user_123",
  featureId: "ai-tokens",
  requiredBalance: 1000,
  sendEvent: true,
  lock: {
    enabled: true,
    lockId: "completion_abc123",
    expiresAt: Date.now() + 5 * 60 * 1000, // 5 minutes
  },
});

if (!response.allowed) {
  // Customer doesn't have enough balance
}

// Balance is now held — proceed with the operation

response = await autumn.check(
    customer_id="user_123",
    feature_id="ai-tokens",
    required_balance=1000,
    send_event=True,
    lock={
        "enabled": True,
        "lock_id": "completion_abc123",
        "expires_at": int(time.time() * 1000) + 5 * 60 * 1000,
    },
)

if not response.allowed:
    # Customer doesn't have enough balance
    pass

# Balance is now held — proceed with the operation

curl -X POST "https://api.useautumn.com/v1/check" \
  -H "Authorization: Bearer am_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "customer_id": "user_123",
    "feature_id": "ai-tokens",
    "required_balance": 1000,
    "send_event": true,
    "lock": {
      "enabled": true,
      "lock_id": "completion_abc123",
      "expires_at": 1735689600000
    }
  }'

Lock parameters

Parameter	Type	Description
`enabled`	`boolean`	Must be `true` to enable locking
`lock_id`	`string`	A unique identifier for this lock. You’ll use this to finalize later. If omitted, Autumn generates one.
`expires_at`	`number`	Unix timestamp (ms) when the lock auto-expires and releases the held balance. Max 24 hours from now.

Always set an expires_at to prevent balance from being held indefinitely if your finalize call fails. If a lock expires, the held balance is automatically released back to the customer.

Step 2: Do your work

Run whatever operation you reserved balance for. The held balance is guaranteed to be available — no other concurrent request can consume it.

Step 3: Finalize the lock

When the operation completes, call balances.finalize to resolve the held balance.

Confirm the full amount

If the operation used exactly the amount you reserved, confirm the lock:

await autumn.balances.finalize({
  lockId: "completion_abc123",
  action: "confirm",
});

await autumn.balances.finalize(
    lock_id="completion_abc123",
    action="confirm",
)

curl -X POST "https://api.useautumn.com/v1/balances.finalize" \
  -H "Authorization: Bearer am_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "lock_id": "completion_abc123",
    "action": "confirm"
  }'

Release the hold

If the operation failed or was canceled, release the lock to return the held balance:

await autumn.balances.finalize({
  lockId: "completion_abc123",
  action: "release",
});

await autumn.balances.finalize(
    lock_id="completion_abc123",
    action="release",
)

curl -X POST "https://api.useautumn.com/v1/balances.finalize" \
  -H "Authorization: Bearer am_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "lock_id": "completion_abc123",
    "action": "release"
  }'

Adjust the final amount

If the actual usage differs from the reserved amount (common with AI tokens), pass overrideValue to adjust:

// Reserved 1000 tokens, but only used 743
await autumn.balances.finalize({
  lockId: "completion_abc123",
  action: "confirm",
  overrideValue: 743,
});

# Reserved 1000 tokens, but only used 743
await autumn.balances.finalize(
    lock_id="completion_abc123",
    action="confirm",
    override_value=743,
)

curl -X POST "https://api.useautumn.com/v1/balances.finalize" \
  -H "Authorization: Bearer am_sk_..." \
  -H "Content-Type: application/json" \
  -d '{
    "lock_id": "completion_abc123",
    "action": "confirm",
    "override_value": 743
  }'

Autumn will reconcile the difference — returning the unused 257 tokens back to the customer’s balance.

Use cases

AI completions

Reserve a token budget before starting generation, then finalize with the actual token count:

const lockId = `completion_${generateId()}`;

const { allowed } = await autumn.check({
  customerId: "user_123",
  featureId: "ai-tokens",
  requiredBalance: 4000, // max_tokens
  sendEvent: true,
  lock: {
    enabled: true,
    lockId,
    expiresAt: Date.now() + 60_000,
  },
});

if (!allowed) return showUpgradePrompt();

const completion = await openai.chat.completions.create({
  model: "gpt-4",
  max_tokens: 4000,
  messages: [{ role: "user", content: prompt }],
});

await autumn.balances.finalize({
  lockId,
  action: "confirm",
  overrideValue: completion.usage.total_tokens,
});

Long-running jobs

Reserve credits before queuing a job, release if the job fails:

const lockId = `job_${jobId}`;

const { allowed } = await autumn.check({
  customerId: "user_123",
  featureId: "compute-credits",
  requiredBalance: 10,
  sendEvent: true,
  lock: {
    enabled: true,
    lockId,
    expiresAt: Date.now() + 30 * 60_000, // 30 min timeout
  },
});

if (!allowed) throw new Error("Insufficient credits");

try {
  await runJob(jobId);
  await autumn.balances.finalize({ lockId, action: "confirm" });
} catch (error) {
  await autumn.balances.finalize({ lockId, action: "release" });
  throw error;
}

Compared to check + track

For simple operations where you know the cost upfront and the operation is fast, check with sendEvent is simpler — it deducts immediately in one call. Use reservations when:

The final usage amount is unknown at check time (e.g., AI token counts)
The operation can fail after balance is deducted
The operation takes significant time and you don’t want another request to consume the same balance

Getting Started

Configure Pricing

Billing & Subscriptions

Customers

Additional Resources

Balance Locking

Step 1: Check with lock

Lock parameters

Step 2: Do your work

Step 3: Finalize the lock

Confirm the full amount

Release the hold

Adjust the final amount

Use cases

AI completions

Long-running jobs

Compared to check + track

​Step 1: Check with lock

​Lock parameters

​Step 2: Do your work

​Step 3: Finalize the lock

​Confirm the full amount

​Release the hold

​Adjust the final amount

​Use cases

​AI completions

​Long-running jobs

​Compared to check + track

Step 1: Check with lock

Lock parameters

Step 2: Do your work

Step 3: Finalize the lock

Confirm the full amount

Release the hold

Adjust the final amount

Use cases

AI completions

Long-running jobs

Compared to check + track