[DOCS] Resume previous conversations docs missing prompt-cache expiry uncached-token hint

Documentation Type

Missing documentation (feature not documented)

Documentation Location

https://code.claude.com/docs/en/common-workflows

Section/Topic

Resume previous conversations and resumed-session behavior after prompt-cache expiry

Current Documentation

No current code.claude.com page documents the footer hint shown when returning to an older session after prompt-cache expiry or explains that the next turn may send uncached tokens.

The resume docs currently say:

claude --continue continues the most recent conversation in the current directory claude --resume opens a conversation picker or resumes by name * claude --from-pr 123 resumes sessions linked to a specific pull request

Later on the same page, they also say:

* The resumed conversation starts with the same model and configuration as the original 1. Conversation Storage: All conversations are automatically saved locally with their full message history 2. Message Deserialization: When resuming, the entire message history is restored to maintain context 3. Tool State: Tool usage and results from the previous conversation are preserved 4. Context Restoration: The conversation resumes with all previous context intact

The costs guide currently says:

Token costs scale with context size: the more context Claude processes, the more tokens you use. Claude Code automatically optimizes costs through prompt caching (which reduces costs for repeated content like system prompts) and auto-compaction (which summarizes conversation history when approaching context limits).

What's Wrong or Missing?

Changelog v2.1.92 says:

Pro users now see a footer hint when returning to a session after the prompt cache has expired, showing roughly how many tokens the next turn will send uncached

Current docs explain how to resume a conversation and separately explain that prompt caching reduces token usage, but they do not explain:

• that returning to an older session can happen after prompt-cache expiry
• that the next turn may send a larger uncached input than users expect
• that Pro users now get a footer hint with a rough uncached-token estimate before sending the next turn
• where users should look to understand how that hint relates to prompt caching and resumed-session cost behavior

That leaves an important piece of resume behavior undocumented for users trying to understand why an older conversation may be more expensive or slower to continue than a recently active one.

Suggested Improvement

Add a short note to Resume previous conversations that explains:

• if you return to a session after its prompt cache has expired, the next turn may send more uncached context than a recently active session
• Pro users may see a footer hint with a rough estimate of the uncached token count before sending the next turn
• the estimate is approximate and meant as a heads-up about prompt-caching/token-usage implications

Also add a brief cross-reference on the costs page so users who see the hint can understand why resumed older sessions may lose prompt-cache benefits.

Impact

Medium - Makes feature difficult to understand

Additional Context

Affected Pages:

| Page | Context |
|------|---------|
| https://code.claude.com/docs/en/common-workflows | Primary resume-session documentation; currently explains how to resume but not prompt-cache expiry or the new uncached-token footer hint |
| https://code.claude.com/docs/en/costs | Explains prompt caching and token usage broadly, but not resumed-session cache expiry or the new hint |

Total scope: 2 pages affected

Source: Changelog v2.1.92

Exact changelog entry:

Pro users now see a footer hint when returning to a session after the prompt cache has expired, showing roughly how many tokens the next turn will send uncached