> ## Documentation Index
> Fetch the complete documentation index at: https://docs.trymorse.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Billing

> API requests pay from your credits at each model's listed price. Learn the order Morse spends credits in and what a 402 means.

A key pays credits for every request, on every plan. A plan's included models are free to use only in the Morse app, never with a key.

One credit is \$0.01. `GET /v1/models` lists each model's `price` in micros, and 10,000 micros are one credit. A web search or a page fetch costs 1,000 micros, a tenth of a credit. See [Models and privacy tiers](/models).

## The order Morse spends credits in

1. Plan credits, which a paid plan grants each cycle. They expire when the next cycle starts, or when the account moves to Free.
2. Referral credits. They expire 30 days after Morse grants them.
3. Purchased credits. They never expire.

To buy credits, open **Settings** > **API keys** in the Morse app and click **Buy credits**.

## Holds and 402

Before a chat request starts, Morse holds the most the request could cost, which is the prompt plus the output limit at the model's prices. When the request ends, Morse charges what it cost and returns the rest to your balance. A stream cut short pays for what it delivered. Set a lower `max_tokens` or `max_completion_tokens` to lower the hold.

If your balance can't cover the hold, the API answers `402` with the code `insufficient_balance`. A chat on a model outside `e2ee` can still run if your balance covers the prompt and 1,024 output tokens. Morse then lowers the output limit to what your balance covers, and the reply carries the header `X-Output-Limited: balance`.

## The X-Funding header

Every billed reply carries the header `X-Funding`, which says what paid for the request. For a key it is always `credits`. A request that Morse refuses before it bills anything carries no `X-Funding` header.

A key can't read your balance. Check it in the Morse app, under **Settings** > **Plan & usage**.


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