Billtrim for agents

Hand your agent an AWS bill export and it gets the savings back, ranked: the monthly dollar range, the arithmetic with the source of each price, the exact console and CLI steps, how to verify first and how to roll back. It reads only what you send, keeps nothing, needs no AWS credentials and calls no AI model. The same fixed rules as the web app, so the same file always gives the same answer.

Add it to a client

Endpoint: https://billtrim.grain64.com/mcp (MCP Streamable HTTP, JSON responses, no sign-in, no key).

{ "mcpServers": { "billtrim": { "url": "https://billtrim.grain64.com/mcp" } } }

With Claude Code: claude mcp add --transport http billtrim https://billtrim.grain64.com/mcp

Then ask: “Here is my Cost Explorer export. What should I cut first?” and give it the file text.

Tools

Tool	Use it when	Input
`analyze_aws_bill`	you have a Cost Explorer or CUR CSV and want the ranked savings	`csv` (text, up to 2 MB), optional `format` (auto, ce-csv, cur-csv), `max_findings` (1 to 25), `min_monthly_savings_usd`
`explain_aws_usage_type`	you have one line item, for example `USE1-NatGateway-Bytes`, and want what it is, the price and the fix	`usage_type`, optional `service`

Unknown fields are rejected by name, never dropped silently. Errors come back as tool results with a code (file_too_large, not_an_aws_export, no_rows, invalid_input, rate_limited) and the fix in plain words.

What comes back

Per finding: rank, rule, title, the monthly savings range in dollars, why, the evidence lines, the arithmetic, console and CLI steps, how to verify first, the risk and how to roll back, and a link to the decoder page for the line item. Findings are suggestions from a bill, not a look at your account: verify before you change anything. The reply also names the engine version, so a result can be reproduced.

No client handy? Call it directly:

curl -s https://billtrim.grain64.com/mcp \
  -H 'content-type: application/json' \
  -H 'accept: application/json, text/event-stream' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"explain_aws_usage_type","arguments":{"usage_type":"USE1-NatGateway-Bytes"}}}'

Limits

2 MB of CSV per call. For a bigger file, group by Service, Usage Type and Region in Cost Explorer first (see the export guide)
20 calls an hour and 5 a minute per caller
Read-only: the tools cannot change anything in your AWS account, and they never see it

Privacy

The file you send to this endpoint is processed in memory and discarded. Only a call counter is kept: the tool name, whether it worked, how many findings came back, a size bucket and a scrambled caller code. Never the file or any part of it. The web app works differently and keeps totals per account; see what Billtrim keeps.