docs(r2): clarify billing for failed 4xx requests in pricing FAQ

[krys-cf]

What this PR does

Expands the R2 pricing FAQ to clarify which failed (4xx) requests are billed as Class A operations. The previous FAQ only mentioned HTTP 401 Unauthorized as exempt, leaving customers uncertain about other error codes like 412 PreconditionFailed, 403 SignatureDoesNotMatch, and 400 BadDigest.

How this was verified

Empirically tested by firing controlled batches of each error type against a dedicated R2 test bucket and querying the r2OperationsAdaptiveGroups GraphQL analytics dataset for operation counts.

Results:

Status	Error Code	In Analytics?	Billed?
200	OK	Yes	Yes (control)
412	PreconditionFailed	Yes	Yes
400	BadDigest	Yes	Yes
403	SignatureDoesNotMatch	No	No
403	RequestTimeTooSkewed	No	No
401	Unauthorized	No	No (documented)

Rule: Authentication-layer failures (401, 403 from signature/expiry checks) are not billed. Authenticated requests that fail post-auth (412, 400) are billed as Class A operations.

Related

DEE-3763

[cloudflare-docs-bot]

Review

⚠️ 1 warning, 💡 6 suggestions found in commit e845f65.

👉 Fix in your agent 👈

Fix the following review findings in PR #32832 (https://github.com/cloudflare/cloudflare-docs/pull/32832).

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1. Post a comment on this PR for any findings you are skipping, with the finding ID and your reasoning.
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---

## Style Guide Review

### Warnings (1)

#### SG-1e8d52c66854 · Headings must not end with punctuation
- **File:** `src/content/docs/r2/pricing.mdx` line 167
- **Issue:** ### Will I be charged for failed requests to my R2 bucket?
- **Fix:** Remove the trailing question mark: `### Will I be charged for failed requests to my R2 bucket`

### Suggestions (6)

#### SG-4e578668286a · HTTP status codes should be monospace
- **File:** `src/content/docs/r2/pricing.mdx` line 171
- **Issue:** `HTTP 401` appears without backtick formatting
- **Fix:** Format the status code as `HTTP 401` (`HTTP 401`)

#### SG-bfa3147d1341 · HTTP status codes should be monospace
- **File:** `src/content/docs/r2/pricing.mdx` line 172
- **Issue:** `HTTP 403` appears without backtick formatting
- **Fix:** Format the status code as `HTTP 403`

#### SG-b06565c5359a · HTTP status codes should be monospace
- **File:** `src/content/docs/r2/pricing.mdx` line 176
- **Issue:** `HTTP 412` appears without backtick formatting
- **Fix:** Format the status code as `HTTP 412`

#### SG-ef148faa25fc · HTTP status codes should be monospace
- **File:** `src/content/docs/r2/pricing.mdx` line 177
- **Issue:** `HTTP 400` appears without backtick formatting
- **Fix:** Format the status code as `HTTP 400`

#### SG-7dfea7e49c80 · Bullet lists with fewer than three items should be rewritten as prose
- **File:** `src/content/docs/r2/pricing.mdx` line 171
- **Issue:** The `This includes:` list contains only two items
- **Fix:** Consider rewriting the two-item list as prose

#### SG-379ff02c9060 · Bullet lists with fewer than three items should be rewritten as prose
- **File:** `src/content/docs/r2/pricing.mdx` line 176
- **Issue:** The `For example:` list contains only two items
- **Fix:** Consider rewriting the two-item list as prose

Code Review

This code review is in beta and may not always be helpful — use your judgment.

_{No code review issues found.}

Conventions

_{No convention issues found.}

Style Guide Review

Warnings (1)

File	Issue
r2/pricing.mdx line 167	Headings must not end with punctuation — ### Will I be charged for failed requests to my R2 bucket? Fix: Remove the trailing question mark: ### Will I be charged for failed requests to my R2 bucket

Suggestions (6)

File	Issue
r2/pricing.mdx line 171	HTTP status codes should be monospace — HTTP 401 appears without backtick formatting Fix: Format the status code as HTTP 401 (HTTP 401)
r2/pricing.mdx line 172	HTTP status codes should be monospace — HTTP 403 appears without backtick formatting Fix: Format the status code as HTTP 403
r2/pricing.mdx line 176	HTTP status codes should be monospace — HTTP 412 appears without backtick formatting Fix: Format the status code as HTTP 412
r2/pricing.mdx line 177	HTTP status codes should be monospace — HTTP 400 appears without backtick formatting Fix: Format the status code as HTTP 400
r2/pricing.mdx line 171	Bullet lists with fewer than three items should be rewritten as prose — The This includes: list contains only two items Fix: Consider rewriting the two-item list as prose
r2/pricing.mdx line 176	Bullet lists with fewer than three items should be rewritten as prose — The For example: list contains only two items Fix: Consider rewriting the two-item list as prose

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[krys-cf]

Review findings triage

SG-a60a4d16d913 (trailing question mark): Skipping. This is an FAQ section — the previous heading also used a question mark (### Will I be charged for unauthorized requests to my R2 bucket?), and FAQ headings across the docs site consistently use question marks.

SG-08c62ba463c4 (sentence case): Skipping. The heading is already sentence case: "Will I be charged for failed requests to my R2 bucket?" — only "Will" (start of sentence) and "R2" (product name) are capitalized.

SG-9f3667988d6e (2-item bullet list, auth failures): Skipping. The two items have different HTTP status codes (401 vs 403) and the 403 entry includes sub-codes. Bullets are clearer for scanning than prose here.

SG-945c4da1d8fc (2-item bullet list, examples): Skipping. Same reasoning — each example pairs a distinct status code with an error name and cause. Bullets aid scanability.