# Harmonic
ID: 01-harmonic
Page: https://gtmmcps.com/tools/01-harmonic
JSON: https://gtmmcps.com/data/tools/01-harmonic.json
Documentation references: https://gtmmcps.com/docs/01-harmonic/
Category: Data & Enrichment
MCP support: official
Testing: RESEARCHED
API access: enterprise-leaning
Last checked: 2026-09-07
Endpoint check: not-probed; date: Not recorded

A startup and private-company database built for early discovery, tracking a stated 40 million companies, 200 million people and 250 thousand investors, with company search, similar-company lookup, people lookup and saved lists exposed through a console, a REST API and an MCP server.

## MCP links
- https://mcp.api.harmonic.ai
- https://console.harmonic.ai/docs/mcp-server

## Sources
- https://harmonic.ai/pricing
- https://mcp.api.harmonic.ai/.well-known/oauth-protected-resource
- https://console.harmonic.ai/docs/mcp-server
- https://mcp.api.harmonic.ai

## Research notes
Verified 2026-09-07: POST of an MCP initialize to https://mcp.api.harmonic.ai returned HTTP 401 with an invalid_token error instructing the client to clear its tokens and reconnect, which is how a live OAuth-gated MCP server behaves, and the OAuth protected-resource document at the same host resolved and declared read and write scopes. HONEST LIMIT: console.harmonic.ai/docs/mcp-server returns HTTP 200 but is a client-rendered dashboard shell, so no human-readable MCP documentation could be read by an automated fetch on this date. The official call therefore rests on the first-party endpoint plus the two MCP feature lines on harmonic.ai/pricing, not on a docs page whose contents anyone has verified. The tier split is the useful finding for a solo operator: "MCP trial credits" and "Full MCP access" are different things on different packages and neither carries a published price. Cross-reference: this is also a signals product and 05-signals-intent-abm.md could reasonably cross-list it; 01 is treated as canonical. 2026-09-07: https://mcp.api.harmonic.ai returned 401 to an MCP initialize POST (https://mcp.api.harmonic.ai).

## Named capabilities
Tool names below are reported by sources. Their presence is not a successful call.

## CLI evidence
Status: none-found

Read current vendor documentation before configuring or running commands.