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

What the OpenRouter API exposes

Call it yourself

Credential. An OpenRouter API key. OpenRouter documents /credits under its management keys, so use one of those if a regular key is refused.

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
  }
}

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.
• There's no daily spend series Argus polls. Burn comes from the balance series, and the day's total is checked against usage_daily on /key.

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.
• 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. GET /api/v1/key returns the key's own usage, limit and free-tier flag.

Can I get OpenRouter spend per day from the API?

Not as a series. Each response reports its own cost, so sum it per day yourself, or let Argus do it.

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 OpenRouter API key. OpenRouter documents /credits under its management keys, so use one of those if a regular key is refused.

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