The cost of a knowledge base consists of two components:
Token Subscription Fee. When a knowledge base is created, $5.63 is charged for 10 million tokens. These tokens are used for indexing the knowledge base and for all queries to it. This charge repeats monthly.
Hourly Fee for the OpenSearch Database. The knowledge base runs on a cloud database. After the database is created, hourly billing starts. The cost depends on the selected configuration.
When creating the database, choose the smallest suitable configuration. You can increase it later if needed, but downgrading is not supported.
When creating a knowledge base with the minimum configuration:
If needed, you can add tokens at a price of $0.75 per 1,000,000 tokens by clicking Add Tokens on the knowledge base Dashboard:

Additional tokens are valid only until the end of the current billing period. For example, if the next billing date is in two days, the added tokens will expire in two days.
Indexing uses the text-embedding-3-large embedding model, which converts text into vector representations. This is required for indexing data and enabling search and retrieval.
Token usage during indexing depends on the format of the uploaded file. Below is an approximate estimate of token consumption for documents of different sizes:
|
Format |
1 MB |
10 MB |
100 MB |
500 MB |
|
.txt |
240,000 |
2,400,000 |
24,000,000 |
120,000,000 |
|
.csv |
450,000 |
4,500,000 |
45,000,000 |
225,000,000 |
|
.xml |
62,000 |
620,000 |
6,200,000 |
31,000,000 |
|
.htm, .html |
39,000 |
390,000 |
3,900,000 |
19,500,000 |
|
.md |
221,000 |
2,210,000 |
22,100,000 |
110,500,000 |
Actual token usage may vary depending on the structure and content of the file.