The Model Context Protocol
Anthropic publishes an open standard for connecting models to tools and data, a USB for AI; within a year it is adopted by every major laboratory and donated to a foundation.
what had to happen · 55 events back to 1943
Every event this one built on, transitively, in order. Direct influences are marked.
00 · One neuron · 1
I · Foundations · 9
- 1948A mathematical theory of communication
- 1949Cells that fire together wire together
- 1950Programming a computer for playing chess
- 1958The perceptron learns
- 1959Samuel's checkers program coins 'machine learning'
- 1960ADALINE and the least-mean-squares rule
- 1965Moore's law
- 1969Perceptrons
- 1970Reverse-mode automatic differentiation
W1 · The first winter · 2
II · Connection · 3
W2 · The second winter · 6
III · Statistics and data · 10
IV · Deep learning · 11
V · Transformers · 9
- 2017Attention is all you need
- 2017Deep reinforcement learning from human preferences
- 2018GPT: generative pre-training
- 2019GPT-2 and the model too dangerous to release
- 2020Scaling laws for neural language models
- 2020GPT-3
- 2020Learning to summarise from human feedback
- 2021Anthropic is founded
- 2021GitHub Copilot writes code
VI · Everyone · 4
- 2022InstructGPT
- 2023Claude
- 2024Claude 3 catches GPT-4
- 2024Claude learns to use a computerdirect
Every assistant that wanted to read a database, search a codebase or call a service had, until late 2024, needed a custom integration for each one, written against each model's tool-calling format. The Model Context Protocol, published by Anthropic on 25 November 2024 as an open specification with reference servers, defined one interface: a server exposes tools, resources and prompts; a client, the model's host application, discovers and calls them. Write a server once and any compliant model can use it.
It was released quietly and became, within months, the thing agents were built on. OpenAI adopted it in March 2025, Google and Microsoft followed, and the editors and coding tools of 2025 shipped with it. By December 2025 there were more than ten thousand public servers, and Anthropic donated the protocol to a new Agentic AI Foundation under the Linux Foundation, co-founded with OpenAI and Block, so that no single laboratory owned it.
MCP is on this timeline as the plumbing of the agent era, in the way MapReduce was the plumbing of the data era. This site runs an MCP server so that agents can read the timeline the way people do.
what it led to · 1 events downstream, through 2025
Built on it directly: