# v1.7.0 — Pick the model, fall back between models

relay-baton can now choose **which model** each agent CLI runs, and relay
between models of the same agent — not only between agents.

## What changed

- **`--model <id>`** on `run`, `plan`, `execute`, and `handoff`. Passed to the
  agent CLI's own model flag (`codex exec -m`, `claude --model`, `gemini -m`,
  …). Any id works, so models released after this version need no update.
- **Per-agent default model** in config: `agents.<id>.model`
  (e.g. `"claude": { …, "model": "claude-opus-5-5" }`). Absent = the CLI's own
  default, exactly as before.
- **Same-agent model fallback.** Chain entries may be `agent:model`:
  `relay-baton run "…" --chain claude:claude-opus-5-5,claude:claude-sonnet-5,codex`
  — when the first model hits a limit, the baton passes to the next model of
  the same CLI before switching agents.
- **Desktop model picker** next to the Codex/Claude switch: suggestions for
  current models (GPT-6.1 Sol / GPT-6 Astra / GPT-6 Luna; Claude Opus 5.5 /
  Sonnet 5 / Fable 5.1 / Haiku 4.5), or type any id. Empty = CLI default.
  Remembered per agent.
- **Broader fallback detection:** `overloaded_error`, `resource_exhausted`,
  `credit balance is too low`, `context window exceeded`, and codex's
  "You've hit your usage limit" wording.
- Session `session.json` records `activeModel` (requested) and
  `reportedModel` (what claude says it ran, with `--pretty`); handoffs name
  the previous/next hop as `agent:model`.

## Compatibility

- Fully additive. Without `--model` / `agents.<id>.model`, commands are
  byte-identical to v1.6.x. Config and session schemas gain optional fields only.