# USCIS API

> USCIS returns case status and processing times through a workflow and API.

Get processing times returns completion times and inquiry date cutoffs for a form, optionally filtered by category or office. Check case status returns a case’s current status and explanation from a USCIS receipt number.

- Page: https://fous.com/workflows/uscis
- Handle: `@uscis`
- Category: [Government](https://fous.com/workflows/category/government)
- Source website: https://uscis.gov
- Last verified: Sep 29, 2026
- Fous is not affiliated with USCIS.

## Methods

### Check case status

Operation `check_case_status`, version 1. 1 credit per call.

Check the current USCIS case status from a receipt number. Returns the status, full explanation, form type if stated, and the date of the action when stated in the explanation.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `receipt_number` | string | yes | `"ioe 0903-589664"` | USCIS receipt number from your notice, such as IOE0903589664. Spaces, dashes and lowercase letters are accepted. |

**Input schema**

```json
{
  "type": "object",
  "required": [
    "receipt_number"
  ],
  "properties": {
    "receipt_number": {
      "type": "string",
      "description": "USCIS receipt number from your notice, such as IOE0903589664. Spaces, dashes and lowercase letters are accepted.",
      "examples": [
        "ioe 0903-589664",
        "IOE-0903589664"
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "receipt_number": "ioe 0903-589664"
    },
    {
      "receipt_number": "IOE-0903589664"
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `form_type` | string or null | `"N-400"` | Form code, such as N-400, when mentioned in the explanation. |
| `page_link` | string | `"https://egov.uscis.gov/"` | USCIS Case Status Online page. |
| `explanation` | string |  | Full plain-language status explanation from USCIS. |
| `status_title` | string | `"Request for Initial Evidence Was Sent"` | Current case status title. |
| `receipt_number` | string | `"IOE0903589664"` | Normalized USCIS receipt number. |
| `last_action_date` | string or null | `"2018-10-31"` | Date of the status action from the explanation, if stated. |

**Example input**

```json
{
  "receipt_number": "ioe 0903-589664"
}
```

**Example output**

```json
{
  "form_type": "N-400",
  "page_link": "https://egov.uscis.gov/",
  "explanation": "On October 31, 2018, we sent a request for initial evidence for your Form N-400, Application for Naturalization, Receipt Number IOE0903589664. The request for evidence explains what we need from you. …",
  "status_title": "Request for Initial Evidence Was Sent",
  "receipt_number": "IOE0903589664",
  "last_action_date": "2018-10-31"
}
```

### Get processing times

Operation `get_processing_times`, version 1. 1 credit per call.

Find USCIS case processing times for a form, optionally by category and office. Times show when 80% of cases were completed; inquiry dates are the published receipt-date cutoffs. Some service centers are grouped as Service Center Operations.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `form` | string | yes | `"N-400 citizenship"` | Form number or what the form is for, e.g. I-485 green card through family. |
| `office` | string | no | `"Dallas TX"` | Field office or service center, e.g. Dallas TX or Texas Service Center. Leave blank for all offices. |
| `category` | string | no | `"Based on a pending I-485 adjustment application"` | Form category in words, e.g. family-based adjustment applications. Leave blank for all categories. |

**Input schema**

```json
{
  "type": "object",
  "required": [
    "form"
  ],
  "properties": {
    "form": {
      "type": "string",
      "description": "Form number or what the form is for, e.g. I-485 green card through family.",
      "examples": [
        "N-400 citizenship",
        "I-485 green card through family",
        "I-765 work permit"
      ]
    },
    "office": {
      "type": "string",
      "default": "",
      "description": "Field office or service center, e.g. Dallas TX or Texas Service Center. Leave blank for all offices.",
      "examples": [
        "Dallas TX",
        "Texas Service Center"
      ]
    },
    "category": {
      "type": "string",
      "default": "",
      "description": "Form category in words, e.g. family-based adjustment applications. Leave blank for all categories.",
      "examples": [
        "Based on a pending I-485 adjustment application"
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "form": "N-400 citizenship",
      "office": "Dallas TX"
    },
    {
      "form": "I-485 green card through family",
      "office": "Dallas TX"
    },
    {
      "form": "N-400 citizenship"
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `processing_times` | array |  |  |
| `processing_times[].form` | string | `"N-400"` |  |
| `processing_times[].time` | string or null | `"13 months"` |  |
| `processing_times[].months` | number or null | `13` |  |
| `processing_times[].office` | string | `"Dallas TX"` |  |
| `processing_times[].category` | string | `"Application for Naturalization"` |  |
| `processing_times[].page_link` | string | `"https://egov.uscis.gov/processing-times"` |  |
| `processing_times[].case_inquiry_date` | string or null | `"2025-05-28"` |  |
| `processing_times[].last_updated_date` | string or null | `"2026-09-17"` |  |

**Example input**

```json
{
  "form": "N-400 citizenship",
  "office": "Dallas TX"
}
```

**Example output**

```json
{
  "processing_times": [
    {
      "form": "N-400",
      "time": "13 months",
      "months": 13,
      "office": "Dallas TX",
      "category": "Application for Naturalization",
      "page_link": "https://egov.uscis.gov/processing-times",
      "case_inquiry_date": "2025-05-28",
      "last_updated_date": "2026-09-17"
    }
  ]
}
```

## Quick start

Call the API with a Fous API key (`FOUS_API_KEY`). To create one, turn on Developer mode in Fous Studio, then open Keys & connections → API keys (https://app.fous.com/keys).

```bash
# First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY'
: "${FOUS_API_KEY:?Set FOUS_API_KEY before running this example}"

curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 120 \
  -H "Authorization: Bearer $FOUS_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@uscis",
  "visibility": "public",
  "operation": "check_case_status",
  "version": 1,
  "input": {
    "receipt_number": "ioe 0903-589664"
  },
  "response": {
    "format": "json"
  }
}'
```

```python
# Save as fous.py and run with python3 fous.py. No packages needed.
# First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY'
import json
import os
import urllib.error
import urllib.request

api_key = os.environ.get("FOUS_API_KEY")
if not api_key:
    raise RuntimeError("Set FOUS_API_KEY before running this example")

body = json.loads("{\n  \"api\": \"@uscis\",\n  \"visibility\": \"public\",\n  \"operation\": \"check_case_status\",\n  \"version\": 1,\n  \"input\": {\n    \"receipt_number\": \"ioe 0903-589664\"\n  },\n  \"response\": {\n    \"format\": \"json\"\n  }\n}")
request = urllib.request.Request(
    "https://api.fous.com/v1/query",
    data=json.dumps(body).encode("utf-8"),
    headers={
        "Authorization": f"Bearer {api_key}",
        "Content-Type": "application/json",
    },
    method="POST",
)
try:
    with urllib.request.urlopen(request, timeout=120) as response:
        result = json.load(response)
except urllib.error.HTTPError as error:
    raise RuntimeError(f"HTTP {error.code}: {error.read().decode('utf-8', errors='replace')}") from error
if result.get("success") is False:
    raise RuntimeError(result.get("error", {}).get("message", "Request failed"))
print(json.dumps(result["data"]["output"], indent=2))
```

```typescript
// Save as fous.mts and run with npx tsx fous.mts.
// First set your key: export FOUS_API_KEY='YOUR_FOUS_API_KEY'
const apiKey = process.env.FOUS_API_KEY;
if (!apiKey) throw new Error("Set FOUS_API_KEY before running this example");

const response = await fetch("https://api.fous.com/v1/query", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  signal: AbortSignal.timeout(120_000),
  body: JSON.stringify({
  "api": "@uscis",
  "visibility": "public",
  "operation": "check_case_status",
  "version": 1,
  "input": {
    "receipt_number": "ioe 0903-589664"
  },
  "response": {
    "format": "json"
  }
}),
});
type ApiResult = { success: boolean; data?: { output: unknown }; error?: { message: string } };
const result: ApiResult = await response.json();
if (!response.ok || result.success === false) {
  throw new Error(result.error?.message ?? `HTTP ${response.status}`);
}
if (!result.data) throw new Error("Missing API response data");
console.log(result.data.output);
```

Or describe the data in plain language: send `{"api":"@uscis","prompt":"Describe the data you need, with every detail"}` to the same URL. Fous fills in the input, runs the method that fits and returns only the fields you asked for; `data.route.calls[].request` is the exact call it made. Routing is free; the run costs the same.

## Use cases

- Compare processing times across offices.
- Find the inquiry date cutoff for a form.
- Check a case’s current status using its receipt number.
- Identify the form type mentioned in a case explanation.

## FAQ

### Is Fous affiliated with USCIS?

No. Fous is not affiliated with USCIS. This workflow reads the public uscis.gov website and returns its data.

### How much does it cost?

Each run costs 1 credit. With pay-as-you-go, a credit costs 1¢; monthly plans cost less per credit.

### Do I need a USCIS account?

No. You only need a Fous account.

### How current is the data?

Fous gets the data from uscis.gov when you run it; repeating the same request within a day may return the saved result. Fous checks this workflow automatically; it last passed a check on Sep 29, 2026.

### How long is USCIS taking to process a form?

Get processing times returns estimates for a form, optionally filtered by office or category. The times show when 80% of cases were completed.

### What is the current status of a USCIS case?

Check case status returns the current status and full explanation when you provide a receipt number.

### When can I inquire about a delayed case?

Get processing times returns the published receipt-date cutoff for a form, optionally filtered by office or category.

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