1.9.0 — 2026-10-07

Release Notes

An agent declares its own reasoning effort and context tier beside its model, so one runner serves
every agent with the same permissions; and every run records which effort and context it ran at.

Compatibility. Additive. Existing factories — including ones whose runners fix an effort or a
context in their command — load, validate and run unchanged; validate warns about nothing new
unless a runner both fixes a value and has the placeholder for it. Two things are different in an
existing factory:

• A runner whose {model} an agent leaves unset no longer hands the CLI a flag without its value,
  or the literal {model}; the argument is left out, with its option. Such runs failed at spawn.
• Run records gain effort and context, and GET /runs gains reasoning_effort and context;
  older releases and records simply lack them.

Added

• An agent declares its own effort and context, beside its model, and a runner carries
  them with {effort} and {context} placeholders exactly as {model} carries a model —
  "--reasoning-effort={effort}", "--context={context}", or Codex's
  "-c", "model_reasoning_effort={effort}". A runner now describes a CLI and a permission set, and
  is shared by every agent with those permissions whatever its model, effort and context: tuning one
  agent no longer means a new runner and a copied deny list. [defaults] effort and
  [defaults] context fill in for agents that set none; an agent's own value wins. Values are
  passed through as written — Layover keeps no catalog of the levels a model accepts.
• layover validate warns when an agent's effort or context has no placeholder to reach its
  runner, when a runner with a placeholder serves an agent that sets no value and has no default,
  when a runner fixes a value beside its own placeholder (the CLI would get two), when a
  [defaults] value reaches no runner, and when a value is empty.
• Every run records the model, effort and context it ran with, in runs-*.jsonl as effort
  and context, and in GET /runs as reasoning_effort and context; a session's header shows
  them. History says which effort a run used without its transcript. Older records lack the fields.
• layover explain says what each agent runs on, and layover prompt prints it on stderr
  beside the prompt, both read from the command line with the agent's own values filled in.

Fixed

• An unset {model} no longer hands the CLI a flag without its value. "--model", "{model}"
  with no model left --model in front of the next flag, which Copilot CLI refuses outright, and a
  joined --model={model} reached the CLI as that literal text. An argument carrying an unset
  placeholder is now left out whole, together with the option it is the value of. The reference
  factory's Copilot and Codex agents, which declare no model, were affected.

Changed

• For anyone using the crates as a library: Runner::invocation and invocation_with_mcp take a
  Selection instead of a model, spawn::Plan carries a selection, and cost::of_run returns a
  ModelChoice. Runner and McpWiring moved to config/runner.rs and are still reached as
  layover_core::config::Runner.

A rate card is still keyed by model alone. A provider that bills a long-context tier at a higher
rate above a token threshold is not modelled, so a card for such a model is a lower bound on its
long-context runs; Copilot runs are priced from the credits they report and are unaffected.

Install layover-cli 1.9.0

Install prebuilt binaries via shell script

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/KotkaZ/layover-project/releases/download/v1.9.0/layover-cli-installer.sh | sh

Install prebuilt binaries via powershell script

powershell -ExecutionPolicy Bypass -c "irm https://github.com/KotkaZ/layover-project/releases/download/v1.9.0/layover-cli-installer.ps1 | iex"

Install prebuilt binaries via Homebrew

brew install KotkaZ/tap/layover

Install prebuilt binaries into your npm project

npm install @layover/layover-cli@1.9.0

Download layover-cli 1.9.0

File	Platform	Checksum
layover-cli-aarch64-apple-darwin.tar.xz	Apple Silicon macOS	checksum
layover-cli-x86_64-apple-darwin.tar.xz	Intel macOS	checksum
layover-cli-x86_64-pc-windows-msvc.zip	x64 Windows	checksum
layover-cli-aarch64-unknown-linux-gnu.tar.xz	ARM64 Linux	checksum
layover-cli-x86_64-unknown-linux-gnu.tar.xz	x64 Linux	checksum

Verifying GitHub Artifact Attestations

The artifacts in this release have attestations generated with GitHub Artifact Attestations. These can be verified by using the GitHub CLI:

gh attestation verify <file-path of downloaded artifact> --repo KotkaZ/layover-project

You can also download the attestation from GitHub and verify against that directly:

gh attestation verify <file-path of downloaded artifact> --bundle <file-path of downloaded attestation>