Session Pulse

See your Claude Code session at a glance. Session Pulse adds one live line above the prompt with the numbers that decide what your next message costs.

| Segment | What it tells you | |---|---| | ● cache warm 56m | Time left before the prompt cache expires. Turns yellow near the end and red (○ cache cold) once it has expired. | | ctx 216k/1.0M 22% | How much of the context window the conversation fills. | | rewrite ≈ $1.73 | Roughly what it costs to write the current context to the cache again once it goes cold. | | 5h 2% · week 0% | Your subscription's rate-limit use, with the time until each window resets (↻). | | session $3.79 · 16m | What this session has cost so far, and how long it has run. |

Values change colour as they rise: green below 60%, yellow from 60%, red from 85%.

What "cache warm 56m" means

Every message you send makes Claude read the whole conversation again. To make that cheap, Anthropic keeps the conversation in a short-term memory called the prompt cache.

• Warm cache: Claude reads the conversation from memory. It is fast and costs about a tenth of the normal price or less.
• 56m: you have 56 minutes to send your next message before the memory is cleared. Each reply from Claude resets the timer to the full time, 1 hour by default.
• Cold cache: after the timer runs out, the next message must write the whole conversation to memory again. That is the rewrite figure.

With the numbers in the screenshot (216k tokens on Opus 5.5):

| You reply... | Cache | Cost to re-read the conversation | |---|---|---| | within 56 minutes | warm | about $0.04 (cache read, $0.20 per 1M tokens) | | after 56 minutes | cold | about $1.73 (cache write, $8 per 1M tokens) |

In short: while the dot is green, continue the conversation. After a long break, the next message pays the rewrite price. If you no longer need the old conversation, run /clear first and start fresh at almost no cost.

Install

In Claude Code:

/plugin marketplace add mejba13/session-pulse
/plugin install session-pulse@session-pulse

Restart Claude Code. The line appears above the prompt.

Requirements: a Claude Code build with function-hook plugins. Session Pulse was built and tested on Claude Code 2.1.288. That plugin API is early access and may change between releases. If the line stops showing after an update, please open an issue.

Use

| Action | How | |---|---| | Hide or show the line | /pulse | | Change settings | /config, then find session-pulse |

Settings

| Setting | Default | What it does | |---|---|---| | Prompt cache TTL | 1h | Set it to how long your cache lives: 1h or 5m. Drives the countdown and the rewrite price. | | Cache write price (USD per 1M tokens) | 0 | Overrides the built-in price table. Use it for custom or negotiated pricing. 0 uses the table. |

How the numbers are worked out

• Context, rate limits and session cost come straight from Claude Code, the same figures /context, /usage and /cost show.
• The cache countdown starts at the last main-thread response and runs for the configured TTL. It is an estimate: the server keeps the real timer.
• The rewrite estimate is context tokens × cache-write price. The cache-write price is the model's list input price × 2 for a 1h cache, or × 1.25 for a 5m cache:

| Model | Input $/1M | 1h write $/1M | 5m write $/1M | |---|---|---|---| | Fable 5 / 5.1 | 10.00 | 20.00 | 12.50 | | Opus 5.5 | 4.00 | 8.00 | 5.00 | | Opus 5, 4.5–4.8 | 5.00 | 10.00 | 6.25 | | Opus 4 / 4.1 | 15.00 | 30.00 | 18.75 | | Sonnet 5 / 5.5 | 2.00 | 4.00 | 2.50 | | Sonnet 4.x | 3.00 | 6.00 | 3.75 | | Haiku 4.5 | 1.00 | 2.00 | 1.25 |

These are Anthropic first-party API prices. On Bedrock or Vertex AI, or with negotiated rates, set your own price in /config. On a subscription plan the figure is what the same work would cost at API rates.

Privacy

Session Pulse makes no network calls and writes no files. It reads only the usage figures Claude Code already keeps for your session.

Development

git clone https://github.com/mejba13/session-pulse
claude --plugin-dir session-pulse/plugins/session-pulse   # run it without installing

claude plugin validate session-pulse/plugins/session-pulse
claude plugin test session-pulse/plugins/session-pulse

plugins/session-pulse/
├── .claude-plugin/plugin.json   manifest and settings
├── hooks/register.tsx           the line and its data feed
├── hooks/format.ts              price table, countdown and formatting
├── types/index.d.ts             state contract
└── tests/pulse.test.tsx         tests

License

MIT © 2026 Mejba Ahmed