CheckRedirects · URL inspection API

CheckRedirects

CheckRedirects resolves URLs, follows HTTP redirect chains, and returns the final destination, status, hops, headers, timing, TLS details, and errors as a structured API response. Built for developers and data engineers cleaning CRM records, auditing link rot, validating migrations, or checking whether a URL behaves differently by user agent.

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Why we built it

We do a lot of deduplication and record merging on Attio projects. Matching people and companies across messy datasets means resolving redirected URLs at scale, and we wanted something we could call programmatically from our own pipelines, agents, and client integrations. We built CheckRedirects to be the shape we kept reaching for: API-first, easy to provision a key for, and cheap to run at scale.

CheckRedirects ships with the opposite priorities: API-first, programmatic by default, keys issued from a dashboard or a single endpoint call, and an MCP server on top so agents can call it without extra glue. The web app and the MCP server are clients of the same API surface, not separate feature tracks.

It runs in our own pipelines for client work, and it's available for anyone else who wants redirect checks at scale without fighting their tooling to get there.

Capabilities

Six surfaces, one per common task. All accept the same Bearer auth header (Authorization: Bearer httpnd_…) and return JSON.

Single URL inspection

POST /v1/inspect follows 301 / 302 / 303 / 307 / 308 chains and returns the final URL, final status, hops, headers, timing, TLS, and error fields in one structured response. Per-hop data covers status code, method, URL, location header, response time, and TLS details when the hop is HTTPS.

Batch + webhooks

POST /v1/batch accepts a urls array or an items array carrying per-URL data metadata that comes back attached to each result. The schema hard cap is 500 URLs; plan tiers cap at 25 / 200 / 500. On paid plans, batch jobs accept an HTTPS webhook_url; when the job completes, CheckRedirects POSTs a signed JSON payload (X-Signature header) with the job id, status, and URL counts so a consumer can pull the full result set when it's ready.

User-agent comparison

POST /v1/compare-agents tests one URL across up to 10 user agents (or a preset pack) and groups the results by final URL and final status. Useful for surfacing UA-specific redirect behavior like affiliate networks, paywalls, bot-detection redirects, and mobile-only short links.

TLS + HTTPS posture

HTTPS hops include TLS version, cipher, certificate subject, issuer, validity dates, SANs, and chain validity. The outbound transport enforces TLS 1.2 minimum, and webhook callback URLs must be HTTPS.

MCP server

A Model Context Protocol server exposes the same capabilities to MCP-capable agents: check_url, inspect_url, compare_agents, batch_check_and_wait, batch_results, monitor management tools, and Google Sheets export. Drop it into your agent's MCP config and call the tools directly without writing a custom HTTP client.

Code examples

Real endpoints, real auth, copy-pasteable. Replace httpnd_your_key_here with an actual API key from the dashboard.

curl -sS https://api.checkredirects.io/v1/batch \
  -H "Authorization: Bearer httpnd_your_key_here" \
  -H "Content-Type: application/json" \
  -d '{
    "items": [
      {
        "url": "https://example.com",
        "data": { "record_id": "crm_123" }
      },
      {
        "url": "https://neondeerdata.com",
        "data": { "record_id": "crm_456" }
      }
    ],
    "method": "HEAD",
    "follow_redirects": true,
    "max_redirects": 10
  }'

const response = await fetch("https://api.checkredirects.io/v1/inspect", {
  method: "POST",
  headers: {
    Authorization: "Bearer httpnd_your_key_here",
    "Content-Type": "application/json"
  },
  body: JSON.stringify({
    url: "https://example.com",
    method: "HEAD",
    follow_redirects: true,
    max_redirects: 10,
    https_only: true
  })
});

if (!response.ok) {
  throw new Error(await response.text());
}

const result = await response.json();
console.log({
  finalUrl: result.final_url,
  finalStatus: result.final_status,
  hops: result.total_hops,
  chain: result.redirect_chain
});

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "batch_check_and_wait",
    "arguments": {
      "urls": [
        "https://example.com",
        "https://neondeerdata.com"
      ],
      "method": "HEAD",
      "https_only": true
    }
  }
}