API documentation

One GET, one carrier record

FMCSA publishes carrier data as three separate files with padded keys, duplicate rows and dollar amounts recorded in thousands. This API does that join for you and returns one JSON object per carrier, stamped with the date it was read.

Quickstart

No key, no signup, no SDK. Copy this line.

curl https://checkmycarrier.com/v1/carriers/264184

The path segment takes either form: a USDOT number (264184) or an MC docket (MC-133655). Both return the same shape.

Response

{
  "dot_number": "264184",
  "mc_number": "MC133655",
  "legal_name": "SCHNEIDER NATIONAL CARRIERS INC",
  "dba_name": null,
  "usdot_status": "ACTIVE",
  "physical_location": "GREEN BAY, WI",
  "power_units": 9866,
  "fleet_headcount": 11245,
  "mcs150_date": "2026-01-30",
  "authority": {
    "common": "ACTIVE",
    "contract": "ACTIVE",
    "broker": "ACTIVE",
    "revocation_pending": false
  },
  "insurance": {
    "bipd_on_file_usd": 1000000,
    "bipd_required_usd": 1000000,
    "cargo_on_file": true,
    "bond_on_file": true,
    "policies": [
      {
        "form": "BMC-34",
        "insurer": "Old Republic Insurance Company",
        "policy_no": "MWE 314560",
        "max_coverage_usd": 5000,
        "effective_date": "2019-03-01"
      }
    ]
  },
  "source": "FMCSA",
  "snapshot_date": "2026-08-20",
  "disclaimer": "…"
}

Fields

Limits and keys

Anonymous callers get 100 lookups per day, which is enough to evaluate the API properly. Past that, send a key and the cap lifts. A key is issued on the spot — ask for a trial and it appears on the page, no confirmation step and no sales conversation:

curl -H "Authorization: Bearer YOUR_KEY" \
  https://checkmycarrier.com/v1/carriers/MC-133655

Responses are cached for a day, matching how often FMCSA republishes the underlying files; x-cache tells you which side you got. CORS is open, so the endpoint works from a browser or an agent runtime without a proxy.

Monitoring

A lookup answers "what does the record say today". Monitoring answers the harder question — "what changed since I last looked" — which is the one that matters once a carrier is already in your book. Add carriers to a watch list and a daily pass reports authority, insurance, name and address changes.

# watch a carrier (USDOT or MC — the docket resolves to its DOT number)
curl -X POST https://checkmycarrier.com/v1/watch \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "content-type: application/json" \
  -d '{"carrier": "264184"}'

# where changes should be delivered (https only)
curl -X PUT https://checkmycarrier.com/v1/webhook \
  -H "Authorization: Bearer YOUR_KEY" \
  -H "content-type: application/json" \
  -d '{"url": "https://your-app.example/hooks/carrier"}'

# or poll instead, with a cursor that can't skip or repeat an event
curl -H "Authorization: Bearer YOUR_KEY" \
  "https://checkmycarrier.com/v1/events?since=0"

What arrives

{
  "type": "carrier.changed",
  "dot_number": "264184",
  "legal_name": "SCHNEIDER NATIONAL CARRIERS INC",
  "changes": [
    {
      "field": "insurance.bipd_on_file_usd",
      "from": "1000000",
      "to": "0",
      "message": "BIPD insurance on file dropped to zero (was $1,000,000)."
    }
  ],
  "source": "FMCSA",
  "snapshot_date": "2026-08-20",
  "disclaimer": "…"
}

Honest limits, so nothing here surprises you later. Adding a carrier records a baseline immediately, so your first delivery is a real change rather than a dump of everything. The pass runs once a day, shortly after FMCSA republishes — this is a daily record, not a live feed. A webhook is attempted once per pass and the outcome is written down either way, so GET /v1/webhook shows you the delivery history rather than asking you to trust ours. A carrier FMCSA can't answer for on a given day is skipped with its baseline untouched, so a change during an outage is caught on the next pass instead of being lost. And monitoring watches the fields that change meaning — authority, insurance filings, legal name, physical address — not the fleet counters that drift for ordinary reasons.

MCP server

If you are building an agent rather than a service, the same data is exposed as an MCP server over Streamable HTTP. No install, no package — point a client at the endpoint:

{
  "mcpServers": {
    "checkmycarrier": {
      "url": "https://checkmycarrier.com/mcp",
      "headers": { "Authorization": "Bearer YOUR_KEY" }
    }
  }
}

Three tools: lookup_carrier works without a key; watch_carrier and list_changes need one. The tool descriptions carry the same rules the rest of this site does — records describe companies, the snapshot date travels with every answer, and nothing here may be used for an FCRA-regulated purpose.

Errors

Terms of use

The data is FMCSA’s, republished as filed with no rating or score attached. Every response carries a snapshot_date and a disclaimer; both must survive into whatever you build, because the record is only meaningful with the date it was read. This is not a consumer report and may not be used for any purpose regulated by the Fair Credit Reporting Act. Full terms.