Context Window
Industry Definition Set • Entity Resolution Path: /glossary/context-window
Quick Answer / TL;DR
The maximum number of tokens an LLM can process in a single request, including the prompt, conversation history, and tool results.
Key Takeaways
- Maximum tokens an LLM can process in one request.
- Shared between prompt, history, tools, and results.
- Exceeding the window causes truncation or summarization.
- Larger windows enable more complex agentic workflows.
Definitive Statement: The maximum number of tokens an LLM can process in a single request, including the prompt, conversation history, and tool results.
Technical Context & Protocol Usage
- Detailed Explanation
- The context window is a hard limit on LLM input. Models like GPT-4 have 128K token windows, while others may have 32K or 1M. In MCP, the context window is shared between the system prompt, conversation history, tool definitions, and tool results. When the window is exceeded, older messages may be truncated or summarized, potentially losing important context.
Format & Payload Metadata
Format: Token count (e.g., 128K tokens)
Latency: Larger contexts increase inference latency quadratically for full-attention models
Real-World Implementation Use Case
An agent with a 128K context window can hold a long conversation with many tool calls before older context is lost.
Cite This Page
MLA Style:
MCPserver.in Engineering. "Context Window." MCPserver.in Knowledge Hub, 20 July 2026, mcpserver.in/glossary/context-window.
Related Terms
Model Context Protocol (MCP)
An open, secure protocol that standardizes how artificial intelligence agents and large language models (LLMs) exchange context, tools, prompts, and data resources with external servers.
JSON-RPC 2.0
A lightweight, stateless remote procedure call (RPC) protocol defined in JSON that utilizes request, response, and notification message frames.
Stdio Transport (Standard Input/Output)
A local-only transport mechanism where the AI client spawns the MCP server as a child process and communicates via standard input (stdin) and standard output (stdout) channels.
SSE Transport (Server-Sent Events)
A lightweight, unidirectional HTTP-based streaming protocol used by remote MCP servers to push messages to AI clients, with client-to-server writes sent over standard POST requests.
Deploy Secure MCP Clusters
Run remote SSE Model Context Protocol servers in highly secure, fully-managed environment located inside India (Mumbai/Bengaluru).
Deploy Node Now