parseUserAgent
Parses a user agent string to extract device, OS, and browser information. All response fields are top-level. Invalid or unrecognized user agents return HTTP 200 with is_valid false and invalid_reason set, and still return whatever browser, OS and device information could be parsed. A version new...
This record as markdown: /tools/com-api-ninjas-mcp/parseuseragent.md
What parseUserAgent does on API Ninjas
AI agents invoke parseUserAgent to trigger actions in API Ninjas. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call: builds kicked off, notifications sent, workflows started.
| Parameter | Type | Required | Description |
|---|---|---|---|
useragent | string | Yes | User agent string to parse. |
Parameters from the server's own tool schema.
Why parseUserAgent is rated High
parseUserAgent triggers real processes with real consequences. An agent gone sideways doesn't fire it once. It starts dozens of builds, sends mass notifications, or burns through compute before anyone looks up.
Attacks that exploit this kind of access
The rule that runs parseUserAgent safely
PolicyLayer is an MCP gateway: it sits between your AI agents and API Ninjas, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For parseUserAgent, this is the rule to start with:
parseUserAgent stays usable, but rate-capped: a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.
The button opens the PolicyLayer dashboard: create your workspace, connect API Ninjas, apply this rule, and every parseUserAgent call is checked against it from then on.
Questions about parseUserAgent
Parses a user agent string to extract device, OS, and browser information. All response fields are top-level. Invalid or unrecognized user agents return HTTP 200 with is_valid false and invalid_reason set, and still return whatever browser, OS and device information could be parsed. A version newer than the latest known release is reported in warnings rather than treated as invalid. It is categorised as a Execute tool in the API Ninjas MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.
parseUserAgent accepts 1 parameter: useragent. Required: useragent. The full parameter table on this page comes from the server's own tool schema.
Register the API Ninjas MCP server in PolicyLayer and add a rule for parseUserAgent: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches API Ninjas. Nothing to install.
parseUserAgent is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.
Yes. Add a rate_limit block to the parseUserAgent rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for parseUserAgent. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
parseUserAgent is provided by the API Ninjas MCP server (https://mcp.api-ninjas.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
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