Quickstart: your first Helium API call in 5 minutes

Helium is a REST API for fundraising research — investor/LP/family-office search and scoring, single-investor deep-dive enrichment, and competitor research. Access requires an active $50/month subscription (6,000 credits/month, plus optional add-on packs) — see Credits & Pricing for the full billing model.

Just want to ask questions in Slack, no code required? See Add Helium to Slack instead — this page is for the REST API / MCP integration path.

1. Get a subscription and API key

Unlike Horizon, having a Horizon API key alone does not unlock Helium — every Helium request (REST, MCP, or Slack) is rejected unless your account has an active Helium subscription, regardless of your Horizon credit balance. See Authentication for the two ways to get subscribed and get a key:

New to Gravity — sign up for Helium directly; this creates a new account, a new API key, and starts your $50/month subscription in one step. You start with the subscription's 6,000 monthly credits and$ 0 in the persistent balance (no free trial there — see Credits & Pricing for why).
Already have a Horizon account — subscribe to Helium from your dashboard’s Helium billing card. Your existing API key and Horizon credit balance keep working as-is once the subscription is active.

2. Set your fundraising profile

Unlike Horizon’s enrichment endpoints, search_investors reads from a stored profile rather than taking every filter inline — set it once with PUT /v1/fundraising/profile (free, not billed):

curl https://lite.gravitygtm.com/api/v1/fundraising/profile \
  -X PUT \
  -H "Authorization: Bearer gk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "raise_type": "startup_equity",
    "stage": "seed",
    "sector_tags": ["fintech"],
    "geography": "United States"
  }'

const res = await fetch("https://lite.gravitygtm.com/api/v1/fundraising/profile", {
  method: "PUT",
  headers: {
    Authorization: "Bearer gk_live_YOUR_KEY",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    raise_type: "startup_equity",
    stage: "seed",
    sector_tags: ["fintech"],
    geography: "United States",
  }),
});

import requests

requests.put(
    "https://lite.gravitygtm.com/api/v1/fundraising/profile",
    headers={"Authorization": "Bearer gk_live_YOUR_KEY"},
    json={
        "raise_type": "startup_equity",
        "stage": "seed",
        "sector_tags": ["fintech"],
        "geography": "United States",
    },
    timeout=30,
)

Raising as a fund instead? Use "raise_type": "fund_lp" with fund_name, fund_thesis, check_size_usd, and target_lp_types instead of stage/sector_tags — see the API Reference for the full field list for each raise_type.

3. Make your first search

cURL

curl https://lite.gravitygtm.com/api/v1/fundraising/search-investors \
  -X POST \
  -H "Authorization: Bearer gk_live_YOUR_KEY" \
  -H "Content-Type: application/json" \
  -d '{"effort": "medium", "limit": 10}'

This costs 12 credits at the default medium effort (10 at low, 15 at high — see Credits & Pricing).

4. Read the response

{
  "data": {
    "investors": [
      { "name": "...", "sectorTags": ["fintech"], "score": 61, "tier": "A", "warmPath": false, "rationale": "..." }
    ]
  },
  "credits_charged": 12,
  "credits_remaining": 5988,
  "cached": false,
  "request_id": "b3f1..."
}

credits_remaining is your combined balance across both buckets (monthly subscription credits plus persistent balance) — a fresh Helium-only signup with no persistent credits yet would show 5988 here (6,000 monthly grant minus this call’s 12). See Credits & Pricing for how the split works. cached is always false for Helium’s endpoints today — unlike some of Horizon’s, none of Helium’s research results are currently cached, so every call is a fresh lookup. See Errors & Rate Limits for the full envelope and error shape (shared with Horizon).

Next steps

Authentication — API key format and how subscribing works
Credits & Pricing — the subscription, add-on packs, and full per-endpoint cost table
MCP install — wire Helium into Claude, Cursor, or any MCP client
Using Helium in Slack — automated Gmail outreach sequences, currently the only surface with a review UI for each touch before it sends
Monitoring & discovery — reply classification, Calendar meeting-prep briefs, and the lookalike-investor and LinkedIn-engagement monitoring loops that run in the background once Gmail is connected and/or a profile field is set
Explore every endpoint in the API Reference section in the sidebar

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Quickstart: your first Helium API call in 5 minutes

1. Get a subscription and API key

2. Set your fundraising profile

3. Make your first search

4. Read the response

Next steps

​1. Get a subscription and API key

​2. Set your fundraising profile

​3. Make your first search

​4. Read the response

​Next steps

1. Get a subscription and API key

2. Set your fundraising profile

3. Make your first search

4. Read the response

Next steps