In the following example, we send a PATCH request to the Update Firewall Configuration endpoint of the Vercel REST API security group. This request creates a new rule in your project's WAF configuration.
Both the conditionGroup and action body parameters are required fields
A common strategy to protect your web application from specific known threats, can include the following:
- Denying non-browser traffic by targeting non "Mozilla" user-agents, which helps with blocking bots and scrapers.
- Blocking traffic from certain Autonomous System Numbers (ASN) that are known to be associated with malicious activities.
To enable this on your Vercel project, create a custom rule using the following code:
app/api/firewall/route.ts
export async function PATCH() { let baseUrl = 'https://api.vercel.com/v1/security/firewall/config'; let teamId = 'team_a5j...'; let projectId = 'QmTrK...';
const body = JSON.stringify({ action: 'rules.insert', id: null, value: { active: true /** Whether this rule is enabled or not in your Vercel WAF configuration */, name: 'Deny non-browser traffic or blacklisted ASN', description: 'Deny traffic without Mozilla or from a specific ASN', conditionGroup: [ /** Any of the conditions in this array can be true */ { conditions: [ { neg: true, /** Perform negative match */ op: "re", /** Operator used to compare - re equivalent to "Match regex expression" */, type: 'user_agent' /** Parameter from incoming traffic */, value: '.*Mozilla.*', }, ], }, { conditions: [ { op: 'inc' /** Operator used to compare - inc equivalent to "Includes"*/, type: 'geo_as_number' /** Parameter from incoming traffic */, value: ["124", "456", "789"], /** includes any of the number combinations in the array */ }, ], }, ], action: { mitigate: { action: 'deny', rateLimit: null, redirect: null, actionDuration: null, }, }, }, });
let res = await fetch(`${baseUrl}?projectId=${projectId}&teamId=${teamId}`, { method: 'PATCH', headers: { Authorization: `Bearer ${process.env.VERCEL_TOKEN}`, 'Content-Type': 'application/json', }, body, });
if (!res.ok) { return Response.json( { status: 'Failed to update Firewall' }, { status: res.status }, ); }
return Response.json({ status: 'New rule added to Firewall' });}