How to get your OpenRouter API usage, balance and spend programmatically

What the OpenRouter API exposes

Call it yourself

Credential. An inference key gives the account balance and the key's own usage. A management key (OpenRouter settings, then Management keys) also lists per-key usage. It can create and delete keys, so make a dedicated one for monitoring.

curl https://openrouter.ai/api/v1/credits \
  -H "Authorization: Bearer $OPENROUTER_API_KEY"

{ "data": { "total_credits": 150, "total_usage": 53.28 } }

curl https://openrouter.ai/api/v1/key \
  -H "Authorization: Bearer $OPENROUTER_API_KEY"

{
  "data": {
    "label": "sk-or-v1-a1b…",
    "usage": 53.28,
    "usage_daily": 4.12,
    "limit": null,
    "limit_remaining": null,
    "is_free_tier": false
  }
}

curl https://openrouter.ai/api/v1/keys \
  -H "Authorization: Bearer $OPENROUTER_MANAGEMENT_KEY"

{
  "data": [
    {
      "hash": "…",
      "name": "bearscan",
      "label": "sk-or-v1-a1b…",
      "usage": 1.757,
      "usage_daily": 0.129,
      "usage_weekly": 0.821,
      "usage_monthly": 1.757
    }
  ]
}

Gotchas

• Every completion response carries usage.cost, the exact USD for that call, including on streamed responses. It's the most precise per-call cost any LLM provider gives you.
• Balance can dip slightly negative because settlement is async. Requests return 402 until you top up above zero.
• OpenRouter charges at each upstream provider's list price; its fee is on the credit purchase (5.5% card, 5% crypto), not per token.
• With an inference key there's no spend series to poll. Burn comes from the balance series after you connect, and the day's total is checked against usage_daily on /key.
• With a management key, month-to-date spend is the chosen key's usage_monthly, so it's right from the first read. Management keys can't make completion calls.
• GET /api/v1/activity covers every key and workspace on the account and can't be filtered to one key, so Argus doesn't use it for a single project's spend.

How OpenRouter charges

Prepaid credits, billed at each upstream provider's list price with no per-token markup — OpenRouter's fee is on the credit purchase (5.5% card, 5% crypto).

Free allowance. 50 a day. Free :free model variants.

At zero. Balance can go slightly negative (async settle); 402 until topped up above zero.

• 1,000 requests per day, per key. Paid usage is bounded by credit balance + upstream capacity, not RPM.

Or let Argus track it

Paste the key once. Argus keeps the ledger, and your coding agent reads it through the MCP server.

• Reads the OpenRouter balance every hour and keeps the series, so you get burn per day (top-ups never count as negative spend) and days until it hits zero.
• Pulls OpenRouter's daily cost buckets every hour for month-to-date spend and a projected month-end total.
• Tracks the plan: the allowance, what's used this period, the reset date, and when you cross into overage.
• With the SDK, records the cost OpenRouter reports on each response, so every call is itemized at its exact price.
• Reconciles itemized cost against OpenRouter's own daily total and flags drift, so you know whether the number is exact or an estimate.
• Emails you on low balance, days to zero, a spend spike, or projected overage.
• Hands all of it to your coding agent over MCP, so it can ask what a run cost or how much runway is left without leaving the editor.

> what has openrouter cost today, and how long until it runs out?

get_overview       → openrouter: mtd spend, burn per day, days to zero
get_request_costs  { "provider": "openrouter", "limit": 25 }
get_advisories     → credits_low, spend_spike, rate_limit_low …

Questions

Does OpenRouter have an API for its balance?

Yes. GET /api/v1/credits returns total_credits and total_usage; your balance is the difference, and credits are 1:1 with USD. That balance is account-wide. To see one key's spend, a management key can read that key's usage_daily, usage_weekly and usage_monthly from GET /api/v1/keys.

Can I get OpenRouter spend per day from the API?

Yes, from GET /api/v1/keys (management key: per-key usage_daily, usage_monthly), in daily buckets.

What happens when OpenRouter credits run out?

Balance can go slightly negative (async settle); 402 until topped up above zero. Auto-recharge is available.

What key does Argus need for OpenRouter?

An inference key gives the account balance and the key's own usage. A management key (OpenRouter settings, then Management keys) also lists per-key usage. It can create and delete keys, so make a dedicated one for monitoring.

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