Claude Cost Report API: daily buckets by workspace vs Sume /v1/usage

Anthropic's Cost Report is GET /v1/organizations/cost_report. It takes a required starting_at timestamp, returns spend in daily (1d) time buckets, and can group results by description or workspace_id. Sume answers a different question: GET /v1/usage on Sume sums what one Studio Agent thread, one run, or one generation job cost, rather than spend per calendar day.

This post uses Anthropic's reference page, read 2026-10-02. The page marks the API as beta, so parameters can change.

What parameters does the Cost Report take?

The response is an object with data, has_more and next_page. Each bucket has starting_at, ending_at and results. The example result carries amount as a string, currency USD, cost_type, description, model, token_type, service_tier and workspace_id.

What does Sume return instead?

Per the Usage docs, GET /v1/usage lists the newest ledger rows for the workspace of the API key. Adding thread_id, run_id or job_id adds a summary folded over every row that scope caused, and summary.debited_usd_micros is the figure the docs say to quote. GET /v1/balance returns the USD balance.

The documented query parameters are limit (1 to 100), thread_id, run_id and job_id. The docs I read show no date range or group-by parameter, so a per-day total on Sume means summing rows you have fetched yourself, as in exporting usage to CSV.

import os
import requests

run_id = os.environ["SUME_RUN_ID"]
key = os.environ["SUME_API_KEY"]
r = requests.get(
    "https://api.sume.com/v1/usage",
    params={"run_id": run_id, "limit": 1},
    headers={"Authorization": f"Bearer {key}"},
    timeout=30,
)
r.raise_for_status()
summary = r.json()["data"]["summary"]
print(summary["debited_usd"], summary["final"])

Which one answers which question?

The two endpoints answer different questions, so pick by the question you are asking.

• What did we spend on Claude this week, by workspace? Anthropic's Cost Report, grouped by workspace_id.
• What did this one run or thread cost us on Sume? GET /v1/usage?run_id=... or thread_id=....
• Is the wallet running low? GET /v1/balance on Sume.
• The two are separate ledgers with separate billing; neither endpoint sees the other's spend.

What else did the page show?

The page's list of beta header values includes spend-limit-reads-2026-09-26, and its navigation has a Spend Limits section under Organization. This post did not read those pages, so it makes no claim about what they return. For Sume's own caps, see the spend cap post.