fix(wrangler): add safe command/args handling for telemetry by petebacondarwin · Pull Request #12063 · cloudflare/workers-sdk

petebacondarwin · 2026-01-23T12:07:46Z

This PR improves telemetry safety by introducing explicit control over which command arguments are included in telemetry events, preventing accidental capture of sensitive data like secrets and credentials.

Replaces #11856
Builds on top of #12069 and Builds on top of #12071

Renamed telemetry fields for clarity:
- command → safeCommand (now excludes the "wrangler " prefix, e.g., "d1 list" instead of "wrangler d1 list")
- args → safeArgs (explicitly indicates these are sanitized/safe arguments)
Added logArgs control:
- New logArgs: boolean field in telemetry events and command metadata
- Commands must explicitly opt-in via metadata.logArgs: true to have their arguments logged
- When logArgs: false (default), safeArgs is sent as an empty object {}
Opted-in safe commands (~100 commands) that don't handle sensitive input:
- List/info/get commands (d1 list, kv list, r2 bucket list, etc.)
- Read-only operations (docs, tail, type-generation, etc.)
- Commands with non-sensitive arguments (delete by name, deployments, etc.)
Intentionally excluded sensitive commands:
- secret put, secret delete, secret bulk (handle secret values)
- pages secret put, pages secret delete, pages secret bulk
- hyperdrive create, hyperdrive update (contain connection strings)
Tests
- Tests included/updated
- Automated tests not possible - manual testing has been completed as follows:
- Additional testing not necessary because:
Public documentation
- Cloudflare docs PR(s):
- Documentation not necessary because: bug fix

A picture of a cute animal (not mandatory, but encouraged)

changeset-bot · 2026-01-23T12:07:51Z

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Latest commit: 10b86ae

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create-cloudflare

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commit: 10b86ae

petebacondarwin · 2026-01-23T12:23:39Z

 	let dispatcher: ReturnType<typeof getMetricsDispatcher> | undefined;

 	// Register middleware to capture command info for fallback telemetry
 	const wranglerWithTelemetry = wranglerWithMiddleware.middleware((args) => {
 		// Capture command and args for potential fallback telemetry
 		// (used when yargs validation errors occur before handler runs)
-		command = `wrangler ${args._.join(" ")}`;
-		metricsArgs = args;
+		safeCommand = args._.join(" ");


@MattieTK - do we want this just to be "" since we cannot guarantee that the args don't contain something sensitive?

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vicb

Nice.
I added some comments.
I also see that Devin has comments, have those been addressed?

vicb · 2026-01-26T05:26:02Z

+	 * The command that was used, e.g. `dev`.
+	 * Does not include the "wrangler" prefix.


future proof this in case wrangler is renamed

Suggested change

* The command that was used, e.g. `dev`.

* Does not include the "wrangler" prefix.

* The command that was used, e.g. `dev` without the binary name

wrangler is used throughout this file, including the names of the events; so it will need a full overhaul if we change the name. "binary" is less clear.

vicb · 2026-01-26T05:27:09Z

+	 * When logArgs is false, positional arguments are stripped to prevent
+	 * accidentally capturing secrets in telemetry.


It's nice to see what's stripped, could we also maybe describe what's kept?

Suggested change

* When logArgs is false, positional arguments are stripped to prevent

* accidentally capturing secrets in telemetry.

* When `logArgs` is `false`, positional arguments are stripped to prevent

* accidentally capturing secrets in telemetry.

vicb · 2026-01-26T05:27:41Z

+	 * Named `safeArgs` to distinguish from historical `args` field which
+	 * may have contained sensitive data in older Wrangler versions.


IMO this is noise and not needed

Suggested change

* Named `safeArgs` to distinguish from historical `args` field which

* may have contained sensitive data in older Wrangler versions.

I think this is actually really useful context for why we are not just using command and args here.

vicb · 2026-01-26T05:28:19Z

+	 * Named `safeCommand` to distinguish from historical `command` field which
+	 * may have contained sensitive positional arguments in older Wrangler versions.


IMO this is noise and not needed

Suggested change

* Named `safeCommand` to distinguish from historical `command` field which

* may have contained sensitive positional arguments in older Wrangler versions.

vicb · 2026-01-26T05:29:03Z

+	 * Named `safeCommand` to distinguish from historical `command` field which
+	 * may have contained sensitive positional arguments in older Wrangler versions.
+	 */
+	safeCommand: string;


Telemetry is the last thing that comes to mind about a "safe" command.
Would "sanitized" be a better prefix?

I agree. I'll change the names.

@MattieTK - is that OK with you?

vicb · 2026-01-26T05:29:44Z

+	 * The args and flags that were passed in when running the command.
+	 * All user-inputted string values are redacted, except for some cases where there are set options.


Maybe add an example to ease the understanding?

I see const safeArgs = logArgs ? args : {}; in register-yargs-command.ts

So if my understanding is correct:

"When logArgs is false, this is an empty object." that's true

WHen logArs is true, some sanitization is going on, can we add ref to the relevant code/config (@see ...)

vicb · 2026-01-26T05:30:17Z

+	 * Named `safeArgs` to distinguish from historical `args` field which
+	 * may have contained sensitive data in older Wrangler versions.
+	 */
+	safeArgs: Record<string, unknown>;


Same comment for "safe" that for safeCommand

vicb · 2026-01-26T05:36:12Z

+	 * If true, arguments for this command will be included in telemetry.
+	 *
+	 * @default false - Arguments are not logged by default.
+	 * Set to `true` to explicitly include this command's args in telemetry.


Suggested change

* If true, arguments for this command will be included in telemetry.

*

* @default false - Arguments are not logged by default.

* Set to `true` to explicitly include this command's args in telemetry.

* Whether arguments for this command will be posted to telemetry.

*

* @default false - Arguments are not logged by default.

vicb · 2026-01-26T05:40:28Z

+				// Truncate login commands to just "login" to avoid capturing tokens
+				if (properties.safeCommand?.startsWith("login")) {
+					properties.safeCommand = "login";
 				}
+				// Don't send metrics for telemetry/metrics disable commands
 				if (
-					properties.command === "wrangler telemetry disable" ||
-					properties.command === "wrangler metrics disable"
+					properties.safeCommand === "telemetry disable" ||
+					properties.safeCommand === "metrics disable"
 				) {
 					return;
 				}
+				// Show metrics banner for certain commands
 				if (
-					properties.command === "wrangler deploy" ||
-					properties.command === "wrangler dev" ||
+					properties.safeCommand === "deploy" ||
+					properties.safeCommand === "dev" ||
 					// for testing purposes
-					properties.command === "wrangler docs"
+					properties.safeCommand === "docs"
 				) {


Note: I have created #12029 to clean that up

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devin-ai-integration · 2026-01-26T09:58:18Z

 		description: "Write a single key/value pair to the given namespace",
 		status: "stable",
 		owner: "Product: KV",
+		logArgs: true,
 	},


🔴 Sensitive KV write commands now opt-in to telemetry args logging via metadata.logArgs: true

kv key put and kv bulk put are write operations that accept secret values (inline value or a JSON file containing values) and file paths. This PR’s stated goal is to avoid capturing sensitive data by requiring explicit opt-in for arg logging, but these commands are explicitly opted in.

Actual: Wrangler will include argsUsed/argsCombination and may include allowed args values depending on allow-list; at minimum it records that flags like --path, --metadata, etc. were used, and it can accidentally include values if they become allow-listed later.

Expected: write/secret-bearing commands should keep metadata.logArgs unset/false so telemetry args are always {}.

Impact: privacy/security regression—telemetry collection is re-enabled for commands that often deal with secrets and sensitive file paths.

Click to expand

Relevant opt-in additions:

kvKeyPutCommand sets logArgs: true in metadata: packages/wrangler/src/kv/index.ts:409-414

kvBulkPutCommand sets logArgs: true in metadata: packages/wrangler/src/kv/index.ts:880-885

Telemetry plumbing includes args when logArgs is true: packages/wrangler/src/core/register-yargs-command.ts:223-232

(Refers to lines 409-414)

Recommendation: Remove logArgs: true from KV write commands (at least kv key put and kv bulk put). Only opt in for read-only/non-sensitive commands, and consider adding a test asserting logArgs is false and sanitizedArgs is {} for these commands.

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devin-ai-integration · 2026-01-26T09:58:18Z

 		description: "Enable Sippy on an R2 bucket",
 		status: "stable",
 		owner: "Product: R2",
+		logArgs: true,
 	},


🔴 r2 bucket sippy enable opts in to telemetry args despite taking access keys and credentials

wrangler r2 bucket sippy enable takes highly sensitive credentials (--access-key-id, --secret-access-key, --r2-access-key-id, --r2-secret-access-key, and GCS private key material). This PR intends to prevent accidental capture of secrets, but the command is explicitly opted in to arg logging.

Actual: Since metadata.logArgs is true, Wrangler will send argsUsed/argsCombination derived from the args and may include values if allow-listed later.

Expected: This command should not log args (leave logArgs unset/false).

Impact: privacy/security regression; telemetry starts recording usage of secret-bearing flags for Sippy enable.

Click to expand

Opt-in added here: packages/wrangler/src/r2/sippy.ts:21-26.
The command defines credential flags immediately below (access-key-id, secret-access-key, etc.): packages/wrangler/src/r2/sippy.ts:51-80.

(Refers to lines 21-26)

Recommendation: Remove logArgs: true from r2BucketSippyEnableCommand (and any other commands that accept credentials/secret material). Add/extend tests to ensure logArgs remains false for these commands.

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devin-ai-integration · 2026-01-26T09:58:19Z

 		owner: "Workers: Authoring and Testing",
 		status: "stable",
 		category: "Account",
+		logArgs: true,
 	},


🔴 wrangler login is opted in to telemetry args logging contrary to privacy requirements

This PR’s description explicitly calls out wrangler login as a command that should no longer collect telemetry on argument usage. However, loginCommand is marked with metadata.logArgs: true.

Actual: register-yargs-command will pass full parsed args as sanitizedArgs when logArgs is true (packages/wrangler/src/core/register-yargs-command.ts:223-232). While metrics-dispatcher truncates sanitizedCommand to "login", it still processes and sends sanitized args/flags usage for the login command.

Expected: wrangler login should have logArgs unset/false so sanitizedArgs is always {}.

Impact: privacy regression: argument usage telemetry is still recorded for login.

Click to expand

Opt-in added in login metadata: packages/wrangler/src/user/commands.ts:24-30.

(Refers to lines 24-30)

Recommendation: Remove logArgs: true from loginCommand metadata. Consider adding a unit test verifying sanitizedArgs is {}/argsCombination is empty for wrangler login events.

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- Rename 'command' to 'safeCommand' (without 'wrangler ' prefix) and 'args' to 'safeArgs' in telemetry events - Add 'logArgs' boolean to control whether command arguments are included in telemetry - Commands must explicitly opt-in via metadata.logArgs: true to log arguments - Safe commands (list, info, get, etc.) that don't handle sensitive data opt-in to logging - Sensitive commands (secret put/delete/bulk, hyperdrive create) intentionally do not opt-in - Update fallback telemetry in index.ts to use new format with logArgs: false

… telemetry Move addBreadcrumb call into the command handler where we have access to the safe commandName from the command definition, rather than deriving it from args._ which may contain sensitive user-supplied positional arguments. Remove safeCommand variable from fallback telemetry since we cannot safely derive it from args._. The dispatchGenericCommandErrorEvent now uses empty string for safeCommand.

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devin-ai-integration · 2026-01-26T15:59:56Z

 		owner: "Workers: Authoring and Testing",
 		status: "stable",
 		category: "Account",
+		logArgs: true,
 	},


🔴 Sensitive wrangler login command is incorrectly opted-in to argument telemetry via logArgs: true

wrangler login was intended (per PR description/changeset) to not collect any argument usage telemetry, but it is explicitly opted-in by setting metadata.logArgs: true.

Actual behavior: when wrangler login runs, createHandler() will set logArgs = true and pass the full args object to telemetry (sanitizedArgs = args) (packages/wrangler/src/core/register-yargs-command.ts:223-232). The metrics dispatcher then derives argsUsed/argsCombination from the sanitized arg keys, meaning argument usage is still collected (even if values are later dropped/redacted).

Expected behavior: wrangler login should have metadata.logArgs unset/false so that sanitizedArgs is {} and no argument usage is collected.

Impact: privacy/telemetry policy regression for a security-sensitive auth command; could leak presence of particular flags/options and violates the explicit policy described in the PR.

Click to expand

Relevant code:

loginCommand opts in: packages/wrangler/src/user/commands.ts:25-30

Opt-in causes args to be sent into telemetry pipeline: packages/wrangler/src/core/register-yargs-command.ts:223-232

(Refers to lines 25-30)

Recommendation: Remove logArgs: true from loginCommand metadata (or explicitly set logArgs: false) so wrangler login sends empty sanitizedArgs and collects no argument usage.

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devin-ai-integration · 2026-01-26T15:59:57Z

 		description: "Upload an mTLS certificate",
 		owner: "Product: SSL",
 		status: "stable",
+		logArgs: true,
 	},


🔴 wrangler mtls-certificate upload is incorrectly opted-in to argument telemetry (captures file-path flag usage)

mTlsCertificateUploadCommand sets metadata.logArgs: true even though it takes certificate/private-key file paths (--cert, --key). The changeset states that commands with file paths that could reveal sensitive structure should not collect argument usage telemetry.

Actual behavior: with logArgs enabled, Wrangler will include argsUsed/argsCombination for this command, indicating the use of file path flags. While values may be redacted/dropped later, the command is still opted into argument usage telemetry.

Expected behavior: logArgs should be false so telemetry does not capture argument usage for file-path-bearing commands.

Impact: privacy regression (argument usage telemetry for filesystem-path-bearing commands).

Click to expand

Relevant code:

Opt-in: packages/wrangler/src/mtls-certificate/cli.ts:14-20

(Refers to lines 14-20)

Recommendation: Remove logArgs: true from mTlsCertificateUploadCommand metadata so it does not collect argument usage telemetry.

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petebacondarwin · 2026-01-26T17:26:20Z

Looking at this code after the refactorings, we don't actually need the logArgs:false behaviour any more. The metrics command events never send unsanitized command strings any more, and the logic to only allow approved args already ensure that unsanitized/unapproved args are never sent either.
Closing this PR in favour of a simpler improvement at #12153

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refactor(wrangler): move telemetry events from yargs middleware to command handlers #12055

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petebacondarwin changed the title ~~refactor(wrangler): add safe command/args handling for telemetry~~ fix(wrangler): add safe command/args handling for telemetry Jan 25, 2026

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Move command arg sanitization allow list to command definition behaviours #12133

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fix getAllowedArgs() inheritance logic

c0a7ba3

fix ups

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refactor(wrangler): add safe command/args handling for telemetry #12153

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		* The command that was used, e.g. `dev`.
		* Does not include the "wrangler" prefix.

	* The command that was used, e.g. `dev`.
	* Does not include the "wrangler" prefix.
	* The command that was used, e.g. `dev` without the binary name

		* When logArgs is false, positional arguments are stripped to prevent
		* accidentally capturing secrets in telemetry.

		* Named `safeArgs` to distinguish from historical `args` field which
		* may have contained sensitive data in older Wrangler versions.

		* Named `safeCommand` to distinguish from historical `command` field which
		* may have contained sensitive positional arguments in older Wrangler versions.

		* The args and flags that were passed in when running the command.
		* All user-inputted string values are redacted, except for some cases where there are set options.

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petebacondarwin commented Jan 23, 2026 •

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