# caveman v2.3.0

- Product: caveman (https://whatsnew.fyi/product/caveman)
- Vendor: Julius Brussee
- Date: 2026-08-23
- Version: v2.3.0
- Original notes: https://github.com/JuliusBrussee/caveman/releases/tag/v2.3.0
- Permalink: https://whatsnew.fyi/product/caveman/releases/v2.3.0

What's New is an index, not a publisher: every entry below links to the vendor's own release notes, which are the authoritative source. Entries are labelled where they are hand-curated sample data, pre-releases, or drawn from a secondary source such as a developer blog.

Reuse: the summaries, labels and curation here are © What's New. Quote freely with attribution and a link back; wholesale republication of the corpus is not permitted — terms: https://whatsnew.fyi/terms. The vendors' own release notes remain their publishers'.

---

- **changed** — caveman learn now reports the actual cost of the window from provider-counted usage instead of just token movements
- **added** — Confirmed savings are attributed to a named method — deterministic_remeasure, controlled_holdout, counterfactual_replay, or interrupted_time_series
- **added** — A controlled-holdout harness runs a fix on and off on the same machine to judge changes whose payback lands outside the edited file
- **added** — caveman learn reconcile checks measured spend against a provider usage export and generates a privacy-safe export digest
- **changed** — The gateway buffers non-streaming upstream bodies before replying
- **fixed** — Serve-mode warnings now land in ~/.caveman/proxy.log instead of vanishing
- **changed** — The caveman ruleset's framing clauses were rewritten and the bundled agent skill registry was regenerated
- **removed** — The GitHub Pages landing page is gone

> **Superseded by [v2.3.1](https://github.com/JuliusBrussee/caveman/releases/tag/v2.3.1).** This tag's `install.sh` / `install.ps1` are still pinned at v2.2.0, so the v2.3.0 one-liner bootstraps the previous release. Use v2.3.1.

Learn v3: `caveman learn` now says what the window **cost**, not just how many tokens moved — and every savings number it reports carries the method that measured it.

##### Learn v3 — spend and attributed savings

- The scan reads billing buckets and outcome signals straight from agent transcripts (Claude, Codex, Gemini, opencode) and prices the window from provider-counted usage, so the cost figure is the provider's arithmetic rather than an estimate.
- Confirmed savings are attributed to a **named method** — `deterministic_remeasure`, `controlled_holdout`, `counterfactual_replay`, or `interrupted_time_series`. Rungs are never summed into one blended headline, because a re-counted file and a before/after median are not the same kind of evidence.
- A **controlled-holdout harness** runs a fix on and off on the same machine, so a change whose payback lands somewhere other than the file it edited (a distilled skill, say) can still be judged. Under 5 sessions per arm it returns `insufficient_data` instead of a small win.
- `caveman learn reconcile` checks measured spend against a provider usage export, and a privacy-safe **export digest** makes that export shareable without shipping prompt text.
- Spend, the savings ledger, and holdout reports surface in the CLI and in the `caveman-learn` skill. Spend is what the window cost — never what a fix would return, never projected into a month, and never called verified. On a Max/Plus plan it is the API-equivalent value of the tokens, not money spent.

##### Proxy

- The gateway buffers non-streaming upstream bodies before replying.
- Serve-mode warnings land in `~/.caveman/proxy.log` instead of vanishing.

##### Elsewhere

- The caveman ruleset's framing clauses were rewritten, and the bundled agent skill registry regenerated.
- The GitHub Pages landing page is gone.

##### Runtime

Installs pin the **bin-v1.1.3** companions and **CLI 1.2.4**. All 36 binaries and the signed manifest are published at [bin-v1.1.3](https://github.com/JuliusBrussee/caveman/releases/tag/bin-v1.1.3).

##### Install

```bash
curl -fsSL https://raw.githubusercontent.com/JuliusBrussee/caveman/v2.3.0/install.sh | bash
```

```powershell
irm https://raw.githubusercontent.com/JuliusBrussee/caveman/v2.3.0/install.ps1 | iex
```