# Y Combinator API

> Y Combinator workflow and API: companies and company. Returns companies, name, batch and status as JSON.

Y Combinator data from ycombinator.com: companies and company.

- Page: https://fous.com/tools/y-combinator
- Handle: `@y-combinator`
- Category: [Data](https://fous.com/tools/category/data)
- Source website: https://ycombinator.com/companies
- Last verified: Sep 29, 2026

## Methods

### Get company

Operation `get_company`, version 1. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.

Get a YC company profile by name or YC page link, including founders, social links, and current job count. Fields not shown on the company page are returned as null.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `company` | string | yes | `"https://www.ycombinator.com/companies/stripe"` | The YC company name or its YC company page link, for example Airbnb or https://www.ycombinator.com/companies/airbnb. |

**Input schema**

```json
{
  "type": "object",
  "required": [
    "company"
  ],
  "properties": {
    "company": {
      "type": "string",
      "description": "The YC company name or its YC company page link, for example Airbnb or https://www.ycombinator.com/companies/airbnb.",
      "examples": [
        "https://www.ycombinator.com/companies/stripe",
        "Airbnb",
        "Scale AI"
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "company": "https://www.ycombinator.com/companies/stripe"
    },
    {
      "company": "Airbnb"
    },
    {
      "company": "Scale AI"
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `name` | string | `"Stripe"` |  |
| `batch` | string or null | `"Summer 2009"` |  |
| `status` | string or null | `"Active"` |  |
| `website` | string or null | `"http://stripe.com"` |  |
| `founders` | array |  |  |
| `founders[].name` | string | `"Patrick Collison"` |  |
| `founders[].title` | string or null | `"Founder/CEO"` |  |
| `founders[].linkedin_link` | string or null | `"https://www.linkedin.com/in/patrickcollison/"` |  |
| `location` | string or null | `"San Francisco"` |  |
| `jobs_link` | string | `"https://www.ycombinator.com/companies/stripe/jobs"` |  |
| `team_size` | integer or null | `7000` |  |
| `industries` | array |  |  |
| `founded_year` | integer or null | `2009` |  |
| `social_links` | object |  |  |
| `social_links.github` | string or null | `"https://github.com/stripe"` |  |
| `social_links.twitter` | string or null | `"https://twitter.com/stripe"` |  |
| `social_links.facebook` | string or null | `"https://www.facebook.com/airbnb/"` |  |
| `social_links.linkedin` | string or null | `"https://www.linkedin.com/company/stripe/"` |  |
| `social_links.crunchbase` | string or null | `"https://www.crunchbase.com/organization/airbnb"` |  |
| `yc_page_link` | string | `"https://www.ycombinator.com/companies/stripe"` |  |
| `open_jobs_count` | integer | `3` |  |
| `long_description` | string or null | `"Launched out of Y Combinator’s 2009 Summer batch, Stripe is a global technology company that builds economic infrastruc` |  |
| `one_line_description` | string or null | `"Economic infrastructure for the internet."` |  |

**Example input**

```json
{
  "company": "https://www.ycombinator.com/companies/stripe"
}
```

**Example output**

```json
{
  "name": "Stripe",
  "batch": "Summer 2009",
  "status": "Active",
  "website": "http://stripe.com",
  "founders": [
    {
      "name": "Patrick Collison",
      "title": "Founder/CEO",
      "linkedin_link": "https://www.linkedin.com/in/patrickcollison/"
    },
    {
      "name": "John Collison",
      "title": "Founder/President",
      "linkedin_link": "https://www.linkedin.com/in/johnbcollison/"
    }
  ],
  "location": "San Francisco",
  "jobs_link": "https://www.ycombinator.com/companies/stripe/jobs",
  "team_size": 7000,
  "industries": [
    "Banking as a Service",
    "Fintech",
    "SaaS"
  ],
  "founded_year": 2009,
  "social_links": {
    "github": "https://github.com/stripe",
    "twitter": "https://twitter.com/stripe",
    "facebook": null,
    "linkedin": "https://www.linkedin.com/company/stripe/",
    "crunchbase": null
  },
  "yc_page_link": "https://www.ycombinator.com/companies/stripe",
  "open_jobs_count": 3,
  "long_description": "Launched out of Y Combinator’s 2009 Summer batch, Stripe is a global technology company that builds economic infrastructure for the internet. Businesses of every size—from new startups to public compa…",
  "one_line_description": "Economic infrastructure for the internet."
}
```

### Search companies

Operation `search_companies`, version 1. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.

Find YC-funded companies by keyword, industry, batch, location, hiring, or status. Returns up to 200 companies in directory order; locations match company-listed places.

**Input**

| Field | Type | Required | Example | Description |
|---|---|---|---|---|
| `batch` | string | no | `"W24"` | YC batch, such as Summer 2025 or W24. |
| `query` | string | no | `"payroll"` | Keywords to search, such as payroll. |
| `status` | string | no | `"active"` | Company status, such as active. |
| `industry` | string | no | `"Fintech"` | Industry, such as Fintech or Healthcare. |
| `location` | string | no | `"San Francisco"` | City or country, such as San Francisco or India. |
| `hiring_only` | boolean | no | `true` | Only companies hiring, such as true. |
| `max_results` | integer | no | `5` | Maximum companies to return, such as 25 (up to 200). |

**Input schema**

```json
{
  "type": "object",
  "properties": {
    "batch": {
      "type": "string",
      "default": "",
      "description": "YC batch, such as Summer 2025 or W24.",
      "examples": [
        "W24"
      ]
    },
    "query": {
      "type": "string",
      "default": "",
      "description": "Keywords to search, such as payroll.",
      "examples": [
        "payroll",
        "zzzzzznomatchingyccompanies"
      ]
    },
    "status": {
      "enum": [
        "any",
        "active",
        "acquired",
        "public",
        "inactive"
      ],
      "type": "string",
      "default": "any",
      "description": "Company status, such as active.",
      "examples": [
        "active"
      ]
    },
    "industry": {
      "type": "string",
      "default": "",
      "description": "Industry, such as Fintech or Healthcare.",
      "examples": [
        "Fintech",
        "Healthcare"
      ]
    },
    "location": {
      "type": "string",
      "default": "",
      "description": "City or country, such as San Francisco or India.",
      "examples": [
        "San Francisco",
        "India"
      ]
    },
    "hiring_only": {
      "type": "boolean",
      "default": false,
      "description": "Only companies hiring, such as true.",
      "examples": [
        true
      ]
    },
    "max_results": {
      "type": "integer",
      "default": 25,
      "maximum": 200,
      "minimum": 1,
      "description": "Maximum companies to return, such as 25 (up to 200).",
      "x-fous-developer": true,
      "examples": [
        5
      ]
    }
  },
  "additionalProperties": false,
  "examples": [
    {
      "query": "payroll",
      "industry": "Fintech",
      "max_results": 5
    },
    {},
    {
      "query": "zzzzzznomatchingyccompanies",
      "max_results": 5
    }
  ]
}
```

**Output**

| Field | Type | Example | Description |
|---|---|---|---|
| `companies` | array |  | Matching YC companies in directory order. |
| `companies[].name` | string | `"Grade"` | Company name. |
| `companies[].batch` | string or null | `"Winter 2026"` | YC batch. |
| `companies[].status` | string or null | `"Active"` | Company status. |
| `companies[].website` | string or null | `"https://usegrade.com"` | Company website. |
| `companies[].location` | string or null | `"San Francisco, CA, USA"` | Listed company location. |
| `companies[].team_size` | integer or null | `2` | Reported team size. |
| `companies[].industries` | array |  | Industry categories. |
| `companies[].description` | string or null | `"API for performance-based payroll"` | One-line company description. |
| `companies[].yc_page_link` | string | `"https://www.ycombinator.com/companies/grade"` | Company page on Y Combinator. |

**Example input**

```json
{
  "query": "payroll",
  "industry": "Fintech",
  "max_results": 5
}
```

**Example output**

```json
{
  "companies": [
    {
      "name": "Grade",
      "batch": "Winter 2026",
      "status": "Active",
      "website": "https://usegrade.com",
      "location": "San Francisco, CA, USA",
      "team_size": 2,
      "industries": [
        "Fintech"
      ],
      "description": "API for performance-based payroll",
      "yc_page_link": "https://www.ycombinator.com/companies/grade"
    },
    {
      "name": "Eazipay Inc.",
      "batch": "Winter 2022",
      "status": "Active",
      "website": "https://myeazipay.com",
      "location": "Lagos, LA, Nigeria",
      "team_size": 27,
      "industries": [
        "Fintech",
        "Payments"
      ],
      "description": "Eazipay powers effortless payroll and financial access in Africa.",
      "yc_page_link": "https://www.ycombinator.com/companies/eazipay-inc"
    },
    {
      "name": "Monet",
      "batch": "Summer 2021",
      "status": "Active",
      "website": "https://monet.com.co/",
      "location": "Miami, FL, USA; Remote",
      "team_size": 42,
      "industries": [
        "Fintech"
      ],
      "description": "Payroll-backed loans and cash advances in Latam",
      "yc_page_link": "https://www.ycombinator.com/companies/monet"
    }
  ]
}
```

## Quick start

Replace `YOUR_API_KEY` with a Fous API key. To create one, open Developers at the bottom of Fous Studio, turn on Developer mode, then go to API keys (https://app.fous.com/keys). Change the values in `input` to run the same tool on new data.

```bash
curl 'https://api.fous.com/v1/query' \
  --fail-with-body --silent --show-error --max-time 180 \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H 'Content-Type: application/json' \
  --data-raw '{
  "api": "@y-combinator",
  "visibility": "public",
  "operation": "get_company",
  "version": 1,
  "input": {
    "company": "https://www.ycombinator.com/companies/stripe"
  },
  "response": {
    "format": "json"
  }
}'
```

```python
# Save as fous.py and run with python3 fous.py. No packages needed.
import json
import urllib.error
import urllib.request

api_key = "YOUR_API_KEY"

body = json.loads("{\n  \"api\": \"@y-combinator\",\n  \"visibility\": \"public\",\n  \"operation\": \"get_company\",\n  \"version\": 1,\n  \"input\": {\n    \"company\": \"https://www.ycombinator.com/companies/stripe\"\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=180) 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.
const apiKey = "YOUR_API_KEY";

const response = await fetch("https://api.fous.com/v1/query", {
  method: "POST",
  headers: {
    "Authorization": `Bearer ${apiKey}`,
    "Content-Type": "application/json",
  },
  signal: AbortSignal.timeout(180_000),
  body: JSON.stringify({
  "api": "@y-combinator",
  "visibility": "public",
  "operation": "get_company",
  "version": 1,
  "input": {
    "company": "https://www.ycombinator.com/companies/stripe"
  },
  "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);
```

## Use from an AI assistant

Connect this tool to Claude Code, Claude Desktop, Cursor, VS Code, Codex and any MCP client as its own MCP server. Each method is a typed tool whose arguments are the method’s input.

- Server URL: `https://api.fous.com/mcp/tools/y-combinator`
- Authorization: `Authorization: Bearer <Fous API key>`

**Tools**

- `get_company`: Get company. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.
- `search_companies`: Search companies. 1 credit per completed call. Failed calls without a completed billing receipt are free; completed work can remain charged if delivery is interrupted.
- `fous_get_run`: the result of a run that was still going, by its `request_id`. Free.

Claude Code:

```bash
claude mcp add --scope user --transport http fous-y-combinator https://api.fous.com/mcp/tools/y-combinator --header "Authorization: Bearer ${FOUS_API_KEY:?Set FOUS_API_KEY to your Fous API key}"
```

To give the assistant every tool, connect `https://api.fous.com/mcp`: it finds one with `fous_search_tools` and runs it with `fous_run_tool`. Setup for other clients: https://fous.com/llms-full.txt.

## FAQ

### Can I run it with my own inputs?

Yes. Change the inputs in Studio and press Run, or send new inputs from your code, or ask a connected AI assistant.

### Can I call this Y Combinator tool as an API?

Yes. Send a POST request to /v1/query with your Fous API key and the inputs, and get JSON back.

### How much does it cost?

Each completed run costs 1 credit. Failed runs without a completed receipt are free; completed work can remain charged if delivery is interrupted. With pay as you go, a credit costs 1¢. Monthly plans cost less per credit.

### Do I need a Y Combinator account?

No. You only need a Fous account.

### How current is the data?

Fous gets the data from ycombinator.com when you run it. Some results are reused for up to 24 hours, and results that use your account or key are never reused. It was last verified on Sep 29, 2026.

## Related

- [LinkedIn API](https://fous.com/tools/linkedin.md): LinkedIn returns publicly visible company information, recent company posts, open job listings and details, and similar midsized robotics companies; closed jobs, hidden details, and exhaustive company matches are unavailable.
- [Glassdoor API](https://fous.com/tools/glassdoor.md): Employee reviews and company ratings.
- [CompaniesMarketCap API](https://fous.com/tools/companiesmarketcap.md): CompaniesMarketCap ranks public companies worldwide or by country and industry across size and financial measures, and provides company figures with market-cap history for completed years.
- [YouTube API](https://fous.com/tools/youtube.md): YouTube returns public video, caption, comment and channel details, company channels, and the latest weekly Top Songs chart; inferred dates and some counts may be approximate.
- [Trustpilot API](https://fous.com/tools/trustpilot.md): Trustpilot provides company ratings, reply and location details when available, recent public reviews, and company search results with ratings, review counts, categories, locations, and links.
- [TechCrunch API](https://fous.com/tools/techcrunch.md): TechCrunch returns latest section headlines, keyword search results of up to 50 articles per page, public article text with available live updates, and recent startup funding stories with clearly announced amounts.
- [Yelp API](https://fous.com/tools/yelp.md): Yelp returns local business matches, public profiles, ratings and up to 60 publicly shown reviews; matches are unsponsored and Yelp-ordered, but later results may lack contact or location details.
- [Forbes API](https://fous.com/tools/forbes.md): Forbes provides business news, real-time billionaire rankings and wealth that can change during the trading day, plus ranked Global 2000 companies with financial figures and company profiles.
- [All Data tools](https://fous.com/tools/category/data)