Yc Reader

Alex YangCommunityCreated by Alex Yang

Skill
Tool integration
Data and AI
MIT
Low risk

From the author

Look up Y Combinator companies and batches from the public yc-oss API, a static JSON dataset refreshed daily: company profiles, batch rosters (e.g. W25, S24), companies by industry or tag, top companies, who is hiring, founder-diversity lists, and overall YC stats. Use this skill whenever the user asks about YC-backed startups, a YC batch, YC companies in a sector or tag or that are hiring, the Y Combinator portfolio, or startup and venture research that draws on YC data. Read-only.

— the description by Alex Yang

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

The yc-reader skill provides a structured way to query the public yc-oss API, which contains a daily-refreshed dataset of Y Combinator-backed startups. It allows users to retrieve information about specific companies, batch cohorts, industry-specific lists, and diversity-focused founder data. The skill is designed for research and analysis, enabling users to filter and aggregate data to understand trends within the YC portfolio.

What it does

Retrieves profiles for individual YC-backed companies
Lists companies belonging to specific YC batches
Filters startups by industry, tag, or hiring status
Provides access to aggregated statistics and metadata about the YC ecosystem
Supports queries for diversity-focused founder lists
Enables custom data filtering using JSON processing tools

When to use it

When researching the YC portfolio or specific startup performance
When identifying YC companies currently hiring in a specific sector
When analyzing trends across different YC batches
When looking for companies categorized by specific tags or industries

Advantages

Provides access to a comprehensive, daily-updated dataset
Allows for precise filtering of company data
Enables quick lookup of company profiles and batch rosters
Facilitates data-driven research on the startup ecosystem

Usage examples

“Which companies in the winter-2025 batch are currently hiring?”: The agent fetches the winter-2025 batch data and filters the list to display only those companies where the hiring status is active.
“Show me the top-performing companies in the developer-tools industry.”: The agent queries the developer-tools industry endpoint and cross-references the results to highlight companies marked as top performers.

Install

Download the skill as a ZIP:
https://autogineer.com/agent-skills/himself65/yc-reader/download
Unzip it into the cross-client skills folder of your project:
```
mkdir -p .agents/skills && unzip yc-reader.zip -d .agents/skills
```

Documentation by Alex Yang

Y Combinator Reader (Read-Only)

If your host has not already executed the shell probes below (for example, in Codex), run the commands inside the ! wrappers with its shell tool before choosing a setup path. Use the actual output; if shell access is unavailable, report that limitation.

Fetches Y Combinator company data from the yc-oss/api, an unofficial open-source API that indexes all publicly launched YC companies. The data is sourced from YC's Algolia search index and updated daily via GitHub Actions.

This is a read-only data source. It provides company profiles, batch listings, industry/tag breakdowns, hiring status, and diversity data. No write operations exist — the API serves static JSON files.

No authentication required. The API is public and free. Just use curl to fetch JSON endpoints.

Step 1: Verify Prerequisites

This skill only needs curl (to fetch data) and jq (to parse/filter JSON). Both are pre-installed on most systems.

!`(command -v curl > /dev/null && echo "CURL_OK" || echo "CURL_MISSING") && (command -v jq > /dev/null && echo "JQ_OK" || echo "JQ_MISSING")`

If JQ_MISSING, install it:

# macOS
brew install jq

# Linux (Debian/Ubuntu)
sudo apt-get install jq

If jq is unavailable, you can still fetch raw JSON with curl and parse it inline with Python or other tools — but jq makes filtering much easier.

Step 2: Identify What the User Needs

Match the user's request to the appropriate endpoint. See references/api_reference.md for full details.

User Request	Endpoint	Notes
Overall YC stats	`meta.json`	Company count, batch list, industry/tag lists
All companies	`companies/all.json`	Full dataset (~5,700 companies) — large response
Top companies	`companies/top.json`	~91 top-performing YC companies
Companies hiring	`companies/hiring.json`	~1,400 currently hiring
Non-profit companies	`companies/nonprofit.json`	YC-backed non-profits
Diversity data	`companies/black-founded.json`, `hispanic-latino-founded.json`, `women-founded.json`	Founder diversity
Specific batch	`batches/{batch-name}.json`	e.g., `winter-2026.json`, `spring-2026.json`, `fall-2025.json`
Single company profile	`batches/{batch-name}/{slug}.json`	e.g., `batches/summer-2009/stripe.json`, `batches/winter-2009/airbnb.json`
By industry	`industries/{industry}.json`	e.g., `fintech.json`, `healthcare.json`
By tag	`tags/{tag}.json`	e.g., `ai.json`, `developer-tools.json`

Batch name format

Batches use {season}-{year} format: winter-2026, spring-2026, summer-2026, fall-2025. Older batches follow the same pattern back to summer-2005. The short form (w09, s21) also works for the per-company endpoint.

Industry and tag name format

Use lowercase with hyphens for multi-word names: real-estate, developer-tools, machine-learning.

Step 3: Execute the Request

Base URL

https://yc-oss.github.io/api/

General pattern

# Fetch and pretty-print
curl -s https://yc-oss.github.io/api/companies/top.json | jq .

# Count companies in a result
curl -s https://yc-oss.github.io/api/batches/winter-2025.json | jq length

# Filter by field (e.g., hiring companies in a batch)
curl -s https://yc-oss.github.io/api/batches/winter-2025.json | jq '[.[] | select(.isHiring == true)]'

# Extract specific fields
curl -s https://yc-oss.github.io/api/companies/top.json | jq '.[] | {name, one_liner, batch, team_size, website}'

# Search by name (case-insensitive)
curl -s https://yc-oss.github.io/api/companies/all.json | jq '[.[] | select(.name | test("stripe"; "i"))]'

Key rules

Use -s flag with curl to suppress progress output
Pipe through jq for readable output and filtering
Avoid fetching companies/all.json unless necessary — it's a large response (~5,700 companies). Prefer more specific endpoints (batches, industries, tags) when possible
Use jq select/filter to narrow results client-side when the API doesn't have a specific endpoint for what the user wants
Batch names are lowercase with hyphens — winter-2025 not Winter 2025 or W25
Tag and industry names are lowercase with hyphens — developer-tools not Developer Tools

Common jq filters

Filter	Purpose
`jq length`	Count results
`jq '.[0]'`	First company
`jq '.[:10]'`	First 10 companies
`jq '[.[] \| select(.isHiring == true)]'`	Only hiring companies
`jq '[.[] \| select(.status == "Active")]'`	Only active companies
`jq '[.[] \| select(.team_size > 100)]'`	Companies with 100+ employees
`jq '.[] \| {name, one_liner, batch, website}'`	Select specific fields
`jq '[.[] \| select(.name \| test("query"; "i"))]'`	Search by name
`jq 'sort_by(-.team_size) \| .[:10]'`	Top 10 by team size

Step 4: Present the Results

Summarize rather than dump JSON. For each company, give the name, one-liner, batch, team size, status, hiring status (a growth signal), and website. For a batch, lead with its size and notable companies; for an industry or tag, the count and which companies are top or hiring; for research questions, aggregate stats such as counts, common industries, and team-size distribution. Mention that the dataset refreshes daily.

Step 5: Diagnostics

If a request fails:

Error	Cause	Fix
`404 Not Found`	Invalid batch, industry, or tag name	Check `meta.json` for valid names
Empty array `[]`	No companies match the query	Broaden the search or check spelling
`curl: Could not resolve host`	No internet connection	Check network connectivity
Large/slow response	Fetching `companies/all.json` (5,700+ entries)	Use a more specific endpoint or add `jq` filters

To discover valid batch, industry, and tag names:

# List all batches
curl -s https://yc-oss.github.io/api/meta.json | jq '.batches[].name'

# List all industries
curl -s https://yc-oss.github.io/api/meta.json | jq '.industries[].name'

# List all tags (there are 333+)
curl -s https://yc-oss.github.io/api/meta.json | jq '.tags[].name'

Reference Files

references/api_reference.md — Complete endpoint reference with company schema, all endpoint URLs, and research workflow examples

Read the reference file when you need the exact company field schema, valid batch/industry/tag names, or detailed research workflow patterns.

Files

ATTRIBUTION.mdAdded by AutoGineer878 B
LICENSELicence file added by AutoGineer1.0 KiB
README.md2.0 KiB
SKILL.md6.9 KiB
references/api_reference.md9.9 KiB

references/api_reference.md

yc-oss API Reference

Complete reference for the yc-oss/api, an unofficial open-source API indexing all publicly launched Y Combinator companies.

Base URL: https://yc-oss.github.io/api/

Authentication: None required — all endpoints are public.

Format: Static JSON files, updated daily via GitHub Actions.

Company Schema

Each company object contains:

Field	Type	Description
`id`	number	Internal ID
`name`	string	Company name
`slug`	string	URL-safe identifier
`former_names`	string[]	Previous company names
`small_logo_thumb_url`	string	Logo thumbnail URL
`website`	string	Company website URL
`all_locations`	string	Comma-separated locations
`long_description`	string	Full company description
`one_liner`	string	One-line summary
`team_size`	number	Current team size
`industry`	string	Primary industry
`subindustry`	string	Sub-industry classification
`launched_at`	number	Unix timestamp of YC launch
`tags`	string[]	Category tags
`tags_highlighted`	string[]	Featured tags
`top_company`	boolean	Whether it's a top YC company
`isHiring`	boolean	Currently hiring
`nonprofit`	boolean	Non-profit organization
`batch`	string	YC batch (e.g., "Winter 2026", "Summer 2009")
`status`	string	Company status ("Active", "Acquired", "Inactive", "Public")
`industries`	string[]	All industry classifications
`regions`	string[]	Geographic regions
`stage`	string	Company stage
`url`	string	YC profile URL (ycombinator.com)
`api`	string	API endpoint URL for this company

Endpoints

Metadata

curl -s https://yc-oss.github.io/api/meta.json | jq .

Returns overall statistics: total company count, list of all batches (with counts), all industries (with counts), and all tags (with counts). Use this to discover valid batch/industry/tag names.

Company Collections

Endpoint	Description	Approx. Count
`companies/all.json`	All launched companies	~5,700
`companies/top.json`	Top-performing companies	~91
`companies/hiring.json`	Currently hiring	~1,400
`companies/nonprofit.json`	Non-profit organizations	~42
`companies/black-founded.json`	Black-founded companies	varies
`companies/hispanic-latino-founded.json`	Hispanic/Latino-founded	varies
`companies/women-founded.json`	Women-founded companies	varies

# Top YC companies
curl -s https://yc-oss.github.io/api/companies/top.json | jq '.[:5] | .[] | {name, one_liner, batch, team_size}'

# Currently hiring
curl -s https://yc-oss.github.io/api/companies/hiring.json | jq length

Batches

Pattern: batches/{season}-{year}.json

Seasons: winter, spring, summer, fall

# Winter 2026 batch
curl -s https://yc-oss.github.io/api/batches/winter-2026.json | jq length

# Spring 2026 batch
curl -s https://yc-oss.github.io/api/batches/spring-2026.json | jq '.[:5] | .[] | {name, one_liner}'

# Fall 2025 batch
curl -s https://yc-oss.github.io/api/batches/fall-2025.json | jq .

Historical batches go back to summer-2005.

Single company profile

Pattern: batches/{batch-slug}/{company-slug}.json

Both long (winter-2009) and short (w09) batch slugs work. Company slug is the same lowercase-hyphenated form used in the slug field.

# Airbnb profile
curl -s https://yc-oss.github.io/api/batches/winter-2009/airbnb.json | jq .

# Stripe profile
curl -s https://yc-oss.github.io/api/batches/summer-2009/stripe.json | jq '{name, one_liner, team_size, status}'

Industries

Pattern: industries/{industry-name}.json

Use lowercase with hyphens for multi-word names.

Notable industries:

Industry	Endpoint	Approx. Count
B2B	`industries/b2b.json`	~2,876
Consumer	`industries/consumer.json`	~866
Healthcare	`industries/healthcare.json`	~656
Fintech	`industries/fintech.json`	~607
Engineering/Product/Design	`industries/engineering-product-and-design.json`	~585
Real Estate & Construction	`industries/real-estate-and-construction.json`	~138
Government	`industries/government.json`	~75
Education	`industries/education.json`	~240
Infrastructure	`industries/infrastructure.json`	~261

# Fintech companies
curl -s https://yc-oss.github.io/api/industries/fintech.json | jq '.[:10] | .[] | {name, one_liner, batch, isHiring}'

# Healthcare companies hiring
curl -s https://yc-oss.github.io/api/industries/healthcare.json | jq '[.[] | select(.isHiring == true)] | length'

Tag	Endpoint	Approx. Count
SaaS	`tags/saas.json`	~1,127
Artificial Intelligence	`tags/artificial-intelligence.json`	~908
AI	`tags/ai.json`	~772
Developer Tools	`tags/developer-tools.json`	~537
Marketplace	`tags/marketplace.json`	~347
Open Source	`tags/open-source.json`	~179
Climate	`tags/climate.json`	~142
Crypto/Web3	`tags/crypto-web3.json`	~119
Robotics	`tags/robotics.json`	~78
Automation	`tags/automation.json`	~85

Research Workflows

Analyze the latest YC batch

# Get batch companies
curl -s https://yc-oss.github.io/api/batches/winter-2026.json | jq length

# Summarize by industry
curl -s https://yc-oss.github.io/api/batches/winter-2026.json | jq 'group_by(.industry) | map({industry: .[0].industry, count: length}) | sort_by(-.count)'

# Find hiring companies in the batch
curl -s https://yc-oss.github.io/api/batches/winter-2026.json | jq '[.[] | select(.isHiring == true)] | .[] | {name, one_liner, website}'

Find fintech/finance startups

# All fintech companies
curl -s https://yc-oss.github.io/api/industries/fintech.json | jq '.[:20] | .[] | {name, one_liner, batch, team_size, status}'

# Active fintech companies that are hiring
curl -s https://yc-oss.github.io/api/industries/fintech.json | jq '[.[] | select(.isHiring == true and .status == "Active")] | .[:15] | .[] | {name, one_liner, batch, team_size, website}'

Track hiring trends (growth signal)

# Largest hiring companies
curl -s https://yc-oss.github.io/api/companies/hiring.json | jq 'sort_by(-.team_size) | .[:20] | .[] | {name, team_size, industry, batch}'

# Hiring companies in AI
curl -s https://yc-oss.github.io/api/tags/ai.json | jq '[.[] | select(.isHiring == true)] | sort_by(-.team_size) | .[:15] | .[] | {name, team_size, one_liner}'

Search for a specific company

# Search by name (case-insensitive)
curl -s https://yc-oss.github.io/api/companies/all.json | jq '[.[] | select(.name | test("stripe"; "i"))]'

# Search in one-liners
curl -s https://yc-oss.github.io/api/companies/all.json | jq '[.[] | select(.one_liner | test("payment"; "i"))] | .[:10] | .[] | {name, one_liner, batch}'

Top companies analysis

# Top companies with details
curl -s https://yc-oss.github.io/api/companies/top.json | jq '.[] | {name, one_liner, batch, team_size, status, industry}'

# Top companies by team size
curl -s https://yc-oss.github.io/api/companies/top.json | jq 'sort_by(-.team_size) | .[:10] | .[] | {name, team_size, batch}'

Diversity data

# Women-founded companies in latest batch
curl -s https://yc-oss.github.io/api/companies/women-founded.json | jq '[.[] | select(.batch == "Winter 2026")] | .[] | {name, one_liner}'

# Count by diversity category
curl -s https://yc-oss.github.io/api/companies/black-founded.json | jq length
curl -s https://yc-oss.github.io/api/companies/women-founded.json | jq length

Export for analysis

# CSV export (name, batch, industry, team_size, status)
curl -s https://yc-oss.github.io/api/companies/top.json | jq -r '.[] | [.name, .batch, .industry, .team_size, .status] | @csv' > yc_top.csv

# JSON subset for processing
curl -s https://yc-oss.github.io/api/industries/fintech.json | jq '[.[] | {name, one_liner, batch, team_size, website, isHiring}]' > fintech_yc.json

Discovering Valid Names

When the user asks for a batch, industry, or tag that you're not sure about, query meta.json:

# List all batch names
curl -s https://yc-oss.github.io/api/meta.json | jq '[.batches[] | .name]'

# List all industry names
curl -s https://yc-oss.github.io/api/meta.json | jq '[.industries[] | .name]'

# List all tag names (333+)
curl -s https://yc-oss.github.io/api/meta.json | jq '[.tags[] | .name]'

# Search for a tag name
curl -s https://yc-oss.github.io/api/meta.json | jq '[.tags[] | select(.name | test("fintech"; "i"))]'

Error Reference

Error	Cause	Fix
`404 Not Found`	Invalid endpoint name	Check `meta.json` for valid batch/industry/tag names
Empty array `[]`	No companies match filter	Broaden the jq filter or check spelling
Network error	No internet connection	Check connectivity
Large/slow response	`companies/all.json` is ~5,700 entries	Use specific endpoints (batch, industry, tag) or pipe through `jq '.[:N]'` to limit

Limitations

Read-only — Static JSON files, no search API or query parameters
No founder details — Company profiles don't include individual founder names or bios
No funding data — Funding amounts, valuations, and investor details are not included
No revenue/financial data — Only public metadata (team size, hiring status, industry)
Updated daily — Data may be up to 24 hours behind YC's live directory
Publicly launched only — Stealth companies not yet launched on YC are excluded

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Needs: Needs network access, Needs a command-line tool

Security

What our scanner noticed· Low risk

Instructions that use the network

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Created by

Alex Yang

Publisher

Alex Yang (Community)

Source

himself65/finance-skills · plugins/social-readers/skills/yc-reader · commit a085078

Licence

MIT License (redistribution allowed)

LICENSE (added by AutoGineer from LICENSE)
ATTRIBUTION.md (written by AutoGineer)

Synced

2026-11-09

AutoGineer is not affiliated with or endorsed by Alex Yang or Alex Yang.

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download yc-reader.zip