{"id":22038,"date":"2026-04-30T11:31:14","date_gmt":"2026-04-30T11:31:14","guid":{"rendered":"https:\/\/ideainthebox.com\/index.php\/2026\/04\/30\/a-guide-to-apis-and-mcps-and-mcp-gateways\/"},"modified":"2026-04-30T11:31:14","modified_gmt":"2026-04-30T11:31:14","slug":"a-guide-to-apis-and-mcps-and-mcp-gateways","status":"publish","type":"post","link":"https:\/\/ideainthebox.com\/index.php\/2026\/04\/30\/a-guide-to-apis-and-mcps-and-mcp-gateways\/","title":{"rendered":"A guide to APIs, MCPs, and MCP Gateways"},"content":{"rendered":"
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APIs and MCPs are often mentioned in the same breath as ways that systems can exchange information, but they are designed differently and have different purposes. This article hopes to explain the differences and how software developers and users should approach interaction with each. <\/p>\n

An API is mainly found in software applications, while an MCP (Model Context Protocol), is found in use by large language models. APIs let one application talk to another, and an MCP lets an AI model use data and tools in structured ways. The difference comes about because LLMs, responding to user requests, need to choose which tools it thinks it needs to achieve an outcome. <\/p>\n

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APIs: Simple definition<\/h3>\n
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An API sends a request in an agreed format to another software instance, and receives a response also in an agreed format, with the details of each exchange\u2019s protocols or methods of behaviour hard-coded. Developers write code to call out to an API and creates code to parse, or handle the response. This makes APIs precise and reliable \u2013 although the interchange can falter if either party changes the code governing the API\u2019s behaviour. <\/p>\n

APIs are still important to systems using LLMs, and many AI-based systems rely on APIs to function. A model may request data, and get responses via an API. <\/p>\n<\/div>\n<\/div>\n

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MCPs: Simple definition<\/h3>\n
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MCPs are used when LLMs need access to data in situations like needing to query business data repositories, read the contents of particular files, or trigger an action. MCPs give models a structured way to access multiple data sources via one interface. An MCP server exposes data in a standard format according to rules set up in advance. These rules determine what is available and to whom or what. <\/p>\n

MCP servers expose three kinds of ability: <\/p>\n