Tallybook

Prices every Claude Code and Codex session on your disk, shows what each agent cost over any period, and tells you in plain English what would have been cheaper.

Documentation

No proxy, no API key, nothing leaves your machine. Run it as a CLI, open the same report in your browser with `tallybook --serve`, or add `tallybook-mcp` to Claude Code or Codex and ask the agent itself what it's spending and what would be cheaper.

tallybook --serve: the same report in your browser

_{In your browser · tallybook --serve}

tallybook in the terminal: the report, a week-on-week comparison, and spend by sub-agent

_{In your terminal · tallybook}

More in the [documentation](https://magna-nz.github.io/tallybook/). ## Install ```sh brew install --cask magna-nz/tap/tallybook ``` Also available via `go install github.com/magna-nz/tallybook/cmd/tallybook@latest`, or as a [release download](https://github.com/magna-nz/tallybook/releases/latest). Works on macOS, Linux and Windows. Add the MCP server so your agent can check its own spend mid-session — `tallybook-mcp` ships alongside `tallybook`, so no separate install: ```sh claude mcp add tallybook -- tallybook-mcp # Claude Code ``` For Codex, add it to `~/.codex/config.toml`: ```toml [mcp_servers.tallybook] command = "tallybook-mcp" ``` ## Use ```sh tallybook # this period's report: the five biggest findings tallybook --serve # the same report, findings and sessions in your browser, on localhost tallybook findings # every finding, grouped by what kind of change it asks for tallybook --since 7d --compare # this week against last week: spend, sessions, cache hit rate tallybook finding 1 # finding #1 in full: what happened, why, what to change tallybook finding 1 --evidence # the same, with the sessions behind it tallybook finding 1 --patch # finding #1's fix, as an applyable diff tallybook agents # spend by sub-agent type, with the model and effort each ran at tallybook sessions --sort cost # sessions ranked by what they cost tallybook changes # did a past model swap actually save money? tallybook setup hook # record sessions automatically as they end ``` ## Docs The command reference, the MCP server's tools, configuration, and the privacy model live on the **[documentation site](https://magna-nz.github.io/tallybook/)**. ## License MIT