# Warmly API Patterns

> Warmly's remote MCP server: WorkOS AuthKit OAuth 2.0 + PKCE authentication, RFC 9728 protected-resource metadata, multi-organization scoping, the stateful Streamable HTTP session model, the three read-only visitor-intelligence tools and their fields, credit semantics, error codes, and rate-limit guidance.

- Skill: `wyre-ai/warmly-api-patterns` (Agent Skill)
- Install (CLI): `npx skillmds@latest add wyre-ai/warmly-api-patterns`
- Raw SKILL.md: https://api.skillmd.com/api/skills/wyre-ai/warmly-api-patterns/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: WYRE-AI (https://skillmd.com/u/wyre-ai)
- Updated: 2026-09-17
- Page: https://skillmd.com/skills/wyre-ai/warmly-api-patterns

---


# Warmly MCP Tools & API Patterns

## Overview

Warmly hosts a remote MCP server at `https://opps-api.getwarmly.com/api/mcp` that exposes three read-only tools backed by Warmly's visitor identification platform. Authentication is OAuth 2.0 with PKCE, delegated to a WorkOS AuthKit tenant. Transport is MCP Streamable HTTP and the server is stateful — it issues an `Mcp-Session-Id` on `initialize` that must accompany subsequent requests.

Official docs: [docs.getwarmly.com/mcp](https://docs.getwarmly.com/mcp)

## Anti-triggers

- **Which of the three tools to call, and what to do with the result** — use
  `warmly-visitor-intelligence`.
- **A different hosted OAuth MCP server** — HubSpot and PandaDoc have their
  own tenants, scopes, and session models; use `hubspot-api-patterns` or
  `pandadoc-api-patterns`.

## Connection & Authentication

### MCP Server Endpoint

```
POST https://opps-api.getwarmly.com/api/mcp
Accept: application/json, text/event-stream
```

### OAuth 2.0 via WorkOS AuthKit

Warmly publishes RFC 9728 protected-resource metadata; the authorization server is a WorkOS AuthKit tenant:

```
GET https://opps-api.getwarmly.com/.well-known/oauth-protected-resource
→ authorization_servers: ["https://vigorous-paper-03.authkit.app"]
```

AuthKit's `.well-known/oauth-authorization-server` exposes:

- `authorization_endpoint`: `https://vigorous-paper-03.authkit.app/oauth2/authorize`
- `token_endpoint`: `https://vigorous-paper-03.authkit.app/oauth2/token`
- `registration_endpoint`: `https://vigorous-paper-03.authkit.app/oauth2/register` (Dynamic Client Registration supported)
- `code_challenge_methods_supported`: `["S256"]`
- `grant_types_supported`: `["authorization_code", "refresh_token"]`
- `token_endpoint_auth_methods_supported`: `["none", "client_secret_post", "client_secret_basic"]` — **public PKCE clients are supported**, so `client_secret` may be empty

Scopes used at the IdP: `openid profile email offline_access`. The MCP resource itself has `scopes_supported: []` — no resource-specific scopes are required, only a valid bearer token.

### Multi-Organization Scoping

For accounts with multiple Warmly organizations, every call must pin org context. Two equivalent transports:

- Header (preferred): `X-Warmly-Organization-Id: <uuid>`
- Query: `?organization_id=<uuid>` appended to the MCP URL

The WYRE MCP Gateway uses the header form so the org never leaks into proxy access logs. Single-organization tokens resolve their org server-side; the header is optional.

## Available Tools

All three tools are read-only synchronous calls and do not consume identification credits (a list call returns the same visitors that have already been identified — Warmly bills on identification, not retrieval).

### `list_warm_visitors`

Returns identified site visitors with full enrichment.

Per-visitor fields include:
- Visitor identifier and session(s)
- Company profile (name, domain, industry, employee count)
- Contact profile when available (name, title, email, LinkedIn)
- Pageviews and session timing
- CRM intersection (whether the visitor matches a CRM contact or account)

### `list_warm_accounts`

Visitor activity rolled up to the account/company level.

Per-account fields include:
- Company profile
- Aggregate visit/visitor counts
- First-seen / last-seen timestamps
- Engagement summary (page categories, depth)
- Top contacts identified at that account

### `get_credits_remaining`

Current month's identification credit balance. Useful for catching credit exhaustion before scaling outreach off Warmly data.

## Best Practices

- **Filter before iterating.** Both `list_warm_*` tools return all currently identified visitors/accounts for the period. For large workspaces, narrow by company domain, date window, or engagement threshold in your downstream code rather than asking the model to scan the full payload.
- **Pair with CRM tools.** Warmly's intersection signals tell you whether a visitor is already a known contact/account in your CRM. Combine with the HubSpot or PSA plugins to enrich identified accounts in-place rather than maintaining a separate Warmly list.
- **Watch credits before bulk workflows.** Call `get_credits_remaining` first if a workflow plans to drive prospecting volume off Warmly identifications — credit exhaustion silently stops new visitor enrichment but leaves previously identified visitors visible.
- **Treat as warm, not closed.** Visitor identification is probabilistic at the contact level. Treat `list_warm_visitors` contact data as the *highest-likelihood* identification for an account, not as a confirmed individual buyer signal.

## Error Handling

| Status | Meaning | Likely cause |
|---|---|---|
| 401 `invalid_token` | Missing or expired bearer token | Refresh the OAuth token; check `WWW-Authenticate: Bearer resource_metadata=...` for the auth server |
| 403 | Token valid, organization context wrong | Pass `X-Warmly-Organization-Id` for multi-org accounts, or verify the token's authorized org |
| 400 missing session | `Mcp-Session-Id` not sent | The server is stateful — every tool call must carry the session id issued on `initialize` |
| 5xx | Warmly platform error | Retry with backoff; persistent 5xx → contact Warmly support |

The WYRE MCP Gateway handles the initialize handshake, session id, and token refresh automatically — these are concerns only when connecting to Warmly's MCP directly.

## Rate Limits

Warmly has not published explicit MCP rate limits. The three tools are list reads, not write operations; sustained polling is unnecessary because identifications are batched server-side. A safe pattern is to call `list_warm_visitors` / `list_warm_accounts` no more than once per minute per workspace.