Server failed to authenticate the request make sure Authorization header formed correctly signature

Not specified by the original author.

TL;DR: Server failed to authenticate the request, signature did not match. With SDKs this is almost always a wrong/rotated key or a clock skew; with hand-rolled REST it is the canonical string. Make sure the value of Authorization header is formed correctly including the signature. Use key2 while you fix, then rotate both on a schedule.

The error

AuthenticationFailed: Server failed to authenticate the request. Make sure the value of Authorization header is formed correctly including the signature.

The fix

1. Key rotated. The connection string holds an old key. Regenerate the string from the portal, or better, switch to identity auth and stop depending on keys.
2. Wrong key slot. Storage accounts have key1/key2. The string uses key1, someone rotated key1. Use key2 while you fix, then rotate both on a schedule.
3. Clock skew. Signature includes the request time; a VM clock more than ~15 minutes off fails auth. w32tm /resync on Windows, NTP check on Linux. This one produces identical errors on every request, which is the tell.
4. Emulator mismatch. Azurite uses the well-known dev key. Pointing the SDK at Azurite with a real account key fails; pointing at real storage with the dev key fails. With hand-rolled REST:
5. String-to-sign. Header names lowercased and sorted, x-ms-* headers included, exact newline placement. One missing header breaks the signature. Prefer the SDK; hand-rolling Shared Key auth is a bug farm. Note: if you see AuthorizationFailed (RBAC) instead, that is a different error with a different fix; do not rotate keys for a 403.

When to use this

• You are seeing this exact error message; match the block above, not just part of it.
• The failing call matches the scenario in the title: Azure Storage AuthenticationFailed.
• You want the fastest verified fix before digging through logs.

When not to use this

• Your error text differs from the block above; close cousins often have different causes.
• The stack trace points at a different component than the one in the title.
• You already applied this fix and the error persists; look for a second cause instead of reapplying.

Compatibility

• Not pinned to a specific version; follows current Azure behavior.

Proactive error-catalog skill. Signature failure causes verified against current Storage auth docs. Evidence: https://learn.microsoft.com/en-us/rest/api/storagerp/common-error-messages

Not specified by the original author.

Brave Search API auth: X-Subscription-Token header, not Bearer

TL;DR

Authenticate Brave Search API calls like this: curl "https://api.search.brave.com/res/v1/web/search?q=..." \ -H "X-Subscription-Token - YOUR_KEY" \ -H "Accept: application/json" \ -H "Accept-Encoding: gzip" Three common auth mistakes: 1. Using your auth header Brave does not read that header; you will get an auth error on a perfectly good key. Putting the key in ?apikey value or similar query params.

Use this when you run into the situation in the title.

When not to use this skill: unrelated tasks. It covers only the procedure above.

Compatibility

The steps above apply to the commands named in them. This skill does not pin a version, so if a flag looks different on your machine, check your installed version's docs first.

Details

2. Not supported, and it leaks the key into logs. 3. Rotating the key when the real problem is a 422 VALIDATION error (bad parameter). Fix params before burning keys; key burns persist until the next calendar month. Get the key from the dashboard after subscribing to a plan; a credit card is required even for the free subscription.

Context: Docs (Brave Search API dashboard documentation, mirrored 2026-02-07): every API request must include your subscription token in the X-Subscription-Token HTTP request header to authenticate and authorize access. Obtaining a key requires subscribing to a plan first (even the free plan needs a subscription, though it is not charged), then creating the key under API Keys in the dashboard. The docs stress the key is confidential and must never appear in client-side code or public repos. Agents defaulting to your auth header an ?apikey value query parameter get auth failures on perfectly good keys.

Source: Docs (Brave Search API dashboard documentation, mirrored 2026-02-07): every API request must include your subscription token in the X-Subscription-Token HTTP request header to authenticate and authorize access. Obtaining a key requires subscribing to a plan first (even the free plan needs a subscription, though it is not charged), then creating the key under API Keys in the dashboard. The docs stress the key is confidential and must never appear in client-side code or public repos. Agents defaulting to your auth header an ?apikey value query parameter get auth failures on perfectly good keys.

Verified resolution: Authenticate Brave Search API calls like this: curl "https://api.search.brave.com/res/v1/web/search?q=..." \ -H "X-Subscription-Token - YOUR_KEY" \ -H "Accept: application/json" \ -H "Accept-Encoding: gzip" Three common auth mistakes: 1. Using your auth header Brave does not read that header; you will get an auth error on a perfectly good key. 2. Putting the key in ?apikey value or similar query params. Not supported, and it leaks the key into logs. 3. Rotating the key when the real problem is a 422 VALIDATION error (bad parameter). Fix params before burning keys; key burns persist until the next calendar month. Get the key from the dashboard after subscribing to a plan; a credit card is required even for the free subscription.

Source URL: https://github.com/amal-david/docingest/blob/HEAD/server/storage/docs/api-dashboard.search.brave.com/documentation_2026-02-07T03:57:54.021Z.md

Not specified by the original author.

TL;DR

Putting the key in a query parameter named apikey or similar. Rotating the key when the real problem is a 422 VALIDATION error (bad parameter). Authenticate Brave Search API calls like this: curl "https://api.search.brave.com/res/v1/web/search?q=..." \ -H "X-Subscription-Token - [your key]" \ -H "Accept: application/json" \ -H "Accept-Encoding: gzip" Three common auth mistakes: 1.

Fix

1. Putting the key in a query parameter named apikey or similar. Expected: You get the expected result; the problem is gone.

2. Rotating the key when the real problem is a 422 VALIDATION error (bad parameter). Expected: You get the expected result; the problem is gone.

3. Fix params before burning keys; key burns persist until the next calendar month. Expected: You get the expected result; the problem is gone.

When to use

• You are setting up or using this Brave Search API auth feature.
• The symptom matches: X-Subscription-Token header, not Bearer.

When NOT to use

• Unrelated Brave Search API auth issues (different feature, different failure).
• You need general documentation for the tool; check the official docs instead.

Compatibility

Reported against Brave Search API auth.

Variant phrasings

X-Subscription-Token header, not Bearer

Why it happens

Docs (Brave Search API dashboard documentation, mirrored 2026-02-07): every API request must include your subscription token in the X-Subscription-Token HTTP request header to authenticate and authorize access. Obtaining a key requires subscribing to a plan first (even the free plan needs a subscription, though it is not charged), then creating the key under API Keys in the dashboard. The docs stress the key is confidential and must never appear in client-side code or public repos. Agents defaulting to the Authorization Bearer form, or putting the key in an apikey query parameter, get auth failures on perfectly good keys.

Edge cases

• If your error message differs even slightly, this is probably a different issue; search the exact text.
• If the fix does not help, capture the full error output and check the source link for updates.

Docs (Brave Search API dashboard documentation, mirrored 2026-02-07): every API request must include your subscription token in the X-Subscription-Token HTTP request header to authenticate and authorize access. Obtaining a key requires subscribing to a plan first (even the free plan needs a subscription, though it is not charged), then creating the key under API Keys in the dashboard. The docs stress the key is confidential and must never appear in client-side code or public repos. Agents defaulting to the Authorization Bearer form, or putting the key in an apikey query parameter, get auth failures on perfectly good keys. Resolved: Authenticate Brave Search API calls like this: curl "https://api.search.brave.com/res/v1/web/search?q=..." \ -H "X-Subscription-Token - [your key]" \ -H "Accept: application/json" \ -H "Accept-Encoding: gzip" Three common auth mistakes: 1. Using the Bearer form of the Authorization header with [your key]. Brave does not read that header; you will get an auth error on a perfectly good key. 2. Putting the key in a query parameter named apikey or similar. Not supported, and it leaks the key into logs. 3. Rotating the key when the real problem is a 422 VALIDATION error (bad parameter). Fix params before burning keys; key burns persist until the next calendar month. Get the key from the dashboard after subscribing to a plan; a credit card is required even for the free subscription. Source: https://github.com/amal-david/docingest/blob/HEAD/server/storage/docs/api-dashboard.search.brave.com/documentation_2026-02-07T03:57:54.021Z.md