Developers

MCP Server

Manage professional identities from Claude Code, Claude Desktop, Cursor, or any MCP-compatible AI agent.

# Local (Claude Code, Cursor, Desktop)
npx @onlydata/mcp-server

# Remote (Claude.ai, Streamable HTTP)
https://mcp.onlydata.club/mcp

No API key needed. Read tools work immediately. Write tools use OAuth 2.1 (automatic in Claude.ai).

Claude Code config

{
  "mcpServers": {
    "onlydata": {
      "command": "npx",
      "args": ["@onlydata/mcp-server"]
    }
  }
}

MCP Tools

No tools match your search.

Access levels

No account needed

Search and read all public profiles, verification data, and metadata. Anyone — human or agent — can query OnlyData without authentication.

• Browse and search all public profiles
• Read full profile data (name, headline, about, roles, skills, projects)
• Get verification and provenance JSON for any profile
• Access OpenAPI spec, llms.txt, MCP manifest, sitemap

With account (OAuth 2.1)

Create a free account at /join. Write operations authenticate via OAuth 2.1 with Dynamic Client Registration — no API key setup needed. With an account you can:

• Create and update your own profile
• Set availability signals (open to recruiting, advisory, partnerships)
• Send and receive messages from other members
• Enable cooperative sharing (opt your profile into partner networks)
• Configure what's shareable (email, phone, signals are all user-controlled)

Rate limits

Each caller has a cost budget per 60-second rolling window. Individual MCP tools (and the equivalent HTTP endpoints) consume cost_units according to how expensive they are to run.

Per-call costs (rough):

• 1 — cheap indexed reads: get_profile, get_business, get_dataset_history/snapshots/fields, get_changelog
• 3 — shallow searches: list_profiles, search_profiles, unlisted tools default
• 5 — dataset-scan queries: search_businesses, match_company, get_similar_businesses
• 10 — vector / embedding: semantic_search
• 20 — multi-call fan-out: company_brief, prospect_dashboard, score_person_readiness, create_tailored_resume
• 30 — rendered pages: render_strategy_page
• 50 — browser scans (real $): scan_agent_readiness

Full cost table lives in mcp-server/lib/rate-limit.js — source of truth.

When you exceed budget the MCP tool returns isError: true with payload:

{
  "error": "rate_limit_exceeded",
  "message": "Budget exceeded for 'scan_agent_readiness'. Retry in 27s.",
  "retry_after_seconds": 27,
  "tier": "authenticated",
  "window_ends_at": "2026-04-21T20:15:00.000Z"
}

HTTP endpoints return 429 with the same JSON body plus headers Retry-After: <seconds>, X-RateLimit-Tool, X-RateLimit-Tier, X-RateLimit-Remaining.

A well-behaved agent should read retry_after_seconds, back off, and retry — not tight-loop the same tool call.

REST API

Full OpenAPI 3.0 spec at /openapi.json. Key endpoints:

# List all profiles
curl https://onlydata.club/api/profiles

# Get a profile by slug
curl https://onlydata.club/api/profile/jane-doe

# Authenticated request
curl -H "x-api-key: od_your_key" \
  https://onlydata.club/api/me

// List all profiles
const res = await fetch('https://onlydata.club/api/profiles');
const { profiles } = await res.json();

// Authenticated request
const res = await fetch('https://onlydata.club/api/me', {
  headers: { 'x-api-key': 'od_your_key' }
});

import requests

# List all profiles
res = requests.get('https://onlydata.club/api/profiles')
profiles = res.json()['profiles']

# Authenticated request
res = requests.get(
    'https://onlydata.club/api/me',
    headers={'x-api-key': 'od_your_key'}
)

Authentication

Three methods: OAuth 2.1 (recommended for MCP connections — automatic in Claude.ai), API key (for scripts and direct API calls), or Supabase JWT (browser sessions). MCP connections use OAuth automatically — no setup needed.

# API key (recommended)
curl -H "x-api-key: od_your_key" \
  https://onlydata.club/api/me

# Supabase JWT (browser sessions)
curl -H "Authorization: Bearer eyJ..." \
  https://onlydata.club/api/me

// API key
const res = await fetch('https://onlydata.club/api/me', {
  headers: { 'x-api-key': 'od_your_key' }
});

// Supabase JWT
const res = await fetch('https://onlydata.club/api/me', {
  headers: { 'Authorization': `Bearer ${token}` }
});

import requests

# API key
res = requests.get(
    'https://onlydata.club/api/me',
    headers={'x-api-key': 'od_your_key'}
)

# Supabase JWT
res = requests.get(
    'https://onlydata.club/api/me',
    headers={'Authorization': f'Bearer {token}'}
)

Webhooks

Push and pull data with webhooks. Receive data to trigger enrichment, or subscribe to events when data changes.

Incoming: Ingest Companies

Send companies to OnlyData for entity resolution and enrichment. Each company is matched against existing entities or created as new. The full enrichment pipeline runs automatically.

curl -X POST https://onlydata.club/api/webhooks/ingest \
  -H "Content-Type: application/json" \
  -H "X-Api-Key: YOUR_API_KEY" \
  -d '{
    "companies": [
      {"name": "Acme Corp", "domain": "acme.com", "city": "Boise", "state": "ID"},
      {"name": "TechStart", "domain": "techstart.io"}
    ]
  }'

Response includes entity IDs and which enrichment models were queued:

{
  "ok": true,
  "created": 1,
  "existing": 1,
  "results": [
    {"action": "exists", "id": 1234, "name": "Acme Corp", "domain": "acme.com"},
    {"action": "created", "id": 5678, "name": "TechStart", "domain": "techstart.io",
     "models_queued": ["verify_v1","industry_v2","description_v1","agent_readiness_v2","mx_profile_v2","ai_native_v1","agent_role_v1"]}
  ]
}

Outgoing: Subscribe to Events

Register a URL to receive signed POST requests when data changes. Each delivery includes an HMAC-SHA256 signature in the X-Webhook-Signature header.

curl -X POST https://onlydata.club/api/webhooks \
  -H "Authorization: Bearer YOUR_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://your-app.com/hooks/onlydata", "events": ["business.enriched", "business.classified"]}'

The response includes a secret_shown_once — save it for signature verification. Webhooks auto-disable after 10 consecutive delivery failures.

Signature Verification

const crypto = require('crypto')
const sig = req.headers['x-webhook-signature']
const expected = crypto.createHmac('sha256', YOUR_SECRET).update(JSON.stringify(req.body)).digest('hex')
if (sig !== expected) return res.status(401).send('Bad signature')

Cascade Rules

When upstream fields change, dependent models automatically re-queue. This implements the enrichment pipeline cascade logic:

Domain Verification

Prove ownership of a company domain to get a verified badge. Three methods available — pick whichever fits your setup. Verified companies also auto-elevate team members whose email domains match.

Step 1: Get instructions

curl https://onlydata.club/api/verify-domain/instructions/your-company

Step 2: Choose a method

Step 3: Trigger verification

# DNS verification
curl -X POST https://onlydata.club/api/verify-domain/your-company \
  -H "x-api-key: od_your_key" \
  -H "Content-Type: application/json" \
  -d '{"method": "dns"}'

# File verification
curl -X POST https://onlydata.club/api/verify-domain/your-company \
  -H "x-api-key: od_your_key" \
  -H "Content-Type: application/json" \
  -d '{"method": "file"}'

# Meta tag verification
curl -X POST https://onlydata.club/api/verify-domain/your-company \
  -H "x-api-key: od_your_key" \
  -H "Content-Type: application/json" \
  -d '{"method": "meta"}'

const res = await fetch('https://onlydata.club/api/verify-domain/your-company', {
  method: 'POST',
  headers: {
    'x-api-key': 'od_your_key',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({ method: 'dns' })
});

import requests

res = requests.post(
    'https://onlydata.club/api/verify-domain/your-company',
    headers={'x-api-key': 'od_your_key'},
    json={'method': 'dns'}
)

On success

• Profile gets verified status with green badge
• Verification proof stored in profile_data.domain_verification
• Team members with matching email domains are auto-elevated to verified

Admin override

Admins can verify any profile directly — no DNS/file check needed:

curl -X POST https://onlydata.club/api/admin/verify/your-company \
  -H "x-admin-key: YOUR_ADMIN_KEY" \
  -H "Content-Type: application/json" \
  -d '{"status": "verified", "domain": "yourcompany.com"}'

MCP tool

Agents can verify domains through the MCP server:

// Get instructions (omit method)
{ "tool": "verify_domain", "args": { "slug": "your-company" } }

// Attempt DNS verification
{ "tool": "verify_domain", "args": { "slug": "your-company", "method": "dns" } }

Agent Readiness Scores

Every OnlyData profile with a website is scanned for agent-readiness signals. Scores range 0–100 using Algorithm E — “Spread” (v3, April 2026): web quality is capped at 30 points, llms.txt adds +15, openapi.json +15, ai-plugin.json +10, mcp.json +25, plus small bonuses for JSON-LD and for discovering agent endpoints on developer / docs / api subdomains. The scanner probes developer.<domain>, developers.<domain>, docs.<domain>, and api.<domain> in parallel so companies that expose their API behind a dev subdomain get credit. Soft-404 detection prevents false positives. There are two meaningful ceilings: ~50 for a well-behaved SaaS site that ships llms.txt but no API, and 100 for true agent-native infrastructure with MCP + OpenAPI + ai-plugin. Six underlying categories:

# All scores (ranked)
curl https://onlydata.club/api/agent-readiness

# Single profile
curl https://onlydata.club/api/agent-readiness/producthacker

// All scores
{ "tool": "get_agent_readiness" }

// Single profile
{ "tool": "get_agent_readiness", "args": { "slug": "producthacker" } }

Scans run on a periodic schedule with soft-404 detection. Under Algorithm E (v3), a bare site with only robots.txt + sitemap scores ~15. A well-built SaaS with llms.txt + JSON-LD hits the well-behaved ceiling at ~50. Crossing 50 requires real API exposure — openapi.json, ai-plugin.json, or mcp.json at the root or on a dev subdomain. True agent-native infrastructure with all three reaches 90+.

Agent-readable files

# Fetch LLM description
curl https://onlydata.club/llms.txt

# Fetch OpenAPI spec
curl https://onlydata.club/openapi.json

# Fetch MCP manifest
curl https://onlydata.club/mcp.json