---
title: "POST /projects/{projectId}/usage/compare"
method: POST
path: "/projects/{projectId}/usage/compare"
---

# POST /projects/{projectId}/usage/compare

`POST /projects/{projectId}/usage/compare`

## Request

- Base URL: `https://api.caveman.so/api/v1`
- URL: `https://api.caveman.so/api/v1/projects/{projectId}/usage/compare`
- Auth: one of:
  - OAuth 2
    - Authorization code: `/api/v1/oauth/authorize`
    - Token URL: `/api/v1/oauth/token` scopes: `billing:read`
  - HTTP bearer
  - API key in cookie `cave_access`
  - API key in cookie `__Secure-cave_identity.session_token`

POST /api/v1/projects/{projectId}/usage/compare on the Caveman Cloud control plane. Requires the billing:read scope. Exposed to autonomous agents as the compare_usage action of the caveman_reports tool (read access). Spend, usage, compression, routing, cache, models, traffic shape and verified-savings rollups for the bound project over a time window.

## Request body

- object
  - `baseline` object, required
    - `from` string, date-time, required: Earliest UTC start; current.to must be at most 90 days later.
    - `to` string, date-time, required
  - `current` object, required
    - `from` string, date-time, required
    - `to` string, date-time, required: UTC end, after current.from and at most 90 days after baseline.from.
  - `filters` object
    - `agent` string[]
    - `workflow` string[]
    - `model` string[]
    - `provider` string[]
    - `session_id` string[]
    - `trace_id` string[]

## Response `2XX`

Successful response. Exact status depends on synchronous or durable delivery outcome.

## Other responses

- `4XX`: Structured failure. `error.code` is stable; `error.request_id` is echoed in the x-cave-request-id header.
- `5XX`: Structured failure. `error.code` is stable; `error.request_id` is echoed in the x-cave-request-id header.

---

[API](https://skmtc.dev/caveman/apis/caveman-cloud-api.md) - [All operations](https://skmtc.dev/caveman/apis/caveman-cloud-api/llms.txt) - [OpenAPI document](https://skmtc.dev/caveman/apis/caveman-cloud-api/revisions/508312d01cfc?raw)