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Published equation contexts

Tstart=Tsys+Tmem+Tenv+Ttools+∑i=1kMiT_{\mathrm{start}} = T_{\mathrm{sys}} + T_{\mathrm{mem}} + T_{\mathrm{env}} + T_{\mathrm{tools}} + \sum_{i=1}^{k} M_i

Why this formula appears here

Anthropic ships an interactive walkthrough of a representative session specifically to make this loading concrete, breaking startup context down by component with illustrative token counts: a system prompt around 4,200 tokens, an auto-memory index around 680 tokens, environment information around 280 tokens, MCP tool names around 120 tokens with full schemas deferred until needed, then a global CLAUDE.md around 320 tokens and a project CLAUDE.md around 1,800 tokens in that particular worked example [ 4 ] . The documentation is careful to call these “representative numbers” rather than fixed constants — actual figures move with every project’s own files — but the shape they describe is stable…

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TsysT_{\mathrm{sys}}

Symbol T_sys

TsT_sys is one of the signed contributions combined to compute the quantity on the left.

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TmemT_{\mathrm{mem}}

Symbol T_mem

TmT_mem is one of the signed contributions combined to compute the quantity on the left.

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TenvT_{\mathrm{env}}

Symbol T_env

TeT_env is one of the signed contributions combined to compute the quantity on the left.

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TtoolsT_{\mathrm{tools}}

Symbol T_tools

TtT_tools is one of the signed contributions combined to compute the quantity on the left.

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ii

Symbol i

i appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.

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kk

Symbol k

k appears in the bound of this sum. The bound states where the repeated operation starts, ends, or which values it includes.

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MiM_i

Symbol M_i

the token count of the i -th memory file discovered along the walk from the filesystem root to the working directory, summed over however many, k , are found.

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i=1i=1

Starting index or lower bound: i=1

This label says where the repeated addition, multiplication, or accumulation starts. Read its value or condition together with the article’s description of the index.

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kk

Ending index or upper bound: k

This label says where the repeated addition, multiplication, or accumulation stops. It sets the last term or end of the range.

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How to interpret it

Read it with the definitions, units, and assumptions supplied by the article.

Research cited beside this formula

Published contexts (1)

A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.

Tstart=Tsys+Tmem+Tenv+Ttools+∑i=1kMiT_{\mathrm{start}} = T_{\mathrm{sys}} + T_{\mathrm{mem}} + T_{\mathrm{env}} + T_{\mathrm{tools}} + \sum_{i=1}^{k} M_i

Equation 1 · AI Agents & Systems

How Claude Code's Memory Actually Persists Across Sessions

This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.

Anthropic ships an interactive walkthrough of a representative session specifically to make this loading concrete, breaking startup context down by component with illustrative token counts: a system prompt around 4,200 tokens, an auto-memory index around 680 tokens, environment information around 280 tokens, MCP tool names around 120 tokens with full schemas deferred until needed, then a global CLAUDE.md around 320 tokens and a project CLAUDE.md around 1,800 tokens in that particular worked example [ 4 ] . The documentation is careful to call these “representative numbers” rather than fixed constants — actual figures move with every project’s own files — but the shape they describe is stable…

Meanings in this article

  • TstartT_{\mathrm{start}}: arithmetic settled at launch, and every additional CLAUDE.
  • MiM_i: the token count of the i -th memory file discovered along the walk from the filesystem root to the working directory, summed over however many, k , are found.
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