---
title: "Send JSON-RPC messages to the MCP transport"
method: POST
path: "/api/mcp"
tags: ["mcp"]
---

# Send JSON-RPC messages to the MCP transport

`POST /api/mcp`

## Request

- Base URL: `https://localhost:10000`
- URL: `https://localhost:10000/api/mcp`
- Auth: one of:
  - API key in header `x-public-api-key`
  - HTTP bearer

Dual-era stateless MCP endpoint. Modern 2026-07-28 clients use server/discover and per-request metadata; 2025-era clients use initialize. Both can list and call tools.

## Request body

- union
  - GenericObject
  - GenericObject[]

## Response `200`

JSON-RPC response payload

- union
  - GenericObject
  - GenericObject[]

## Other responses

- `202`: Notification accepted with no JSON-RPC response body
- `401`: Valid API key required
- `403`: Requested operation or field requires API key access
- `429`: Rate limit exceeded

---

[API](https://skmtc.dev/obolusfinanz/apis/obolus-finanz-payroll-api.md) · [All operations](https://skmtc.dev/obolusfinanz/apis/obolus-finanz-payroll-api/llms.txt) · [OpenAPI document](https://skmtc.dev/obolusfinanz/apis/obolus-finanz-payroll-api/revisions/6e44241842e1?raw)