# Alchemist: Pipeline Permutations

Reference for the pipeline shapes a ticket can run through.

---

The Alchemist agent pipeline is content-shape, not time-shape. The two
independent axes the planner is chosen on, and the model that fills each
slot, are pinned in `docs/pipeline-permutations.md` (the design record).
This page is a short in-product pointer to that doc so the model-preferences
panel's **Learn more** link lands somewhere real.

## Tier × slot

- **Plan** -- DEFAULT planner is **glm-5.2** (the `high` rung), routed via
  OpenRouter. `max` tier / explicit request upgrades to **gpt-5.5** (the
  measured plan winner). `fast` drops to **grok-4.3**. `economy` (explicit
  only) drops to **deepseek-v4-pro**.
- **Implement** -- DEFAULT is **minimax-m3** (top fix-quality in the faithful
  implement eval at ~1/25th gpt-5.5's cost). `max` tier upgrades to
  **gpt-5.5**; `trivial` falls through to Sonnet.
- **Review / security / reconcile / merge_resolution** -- frontier (Opus 4.8).
- **Docs** -- Sonnet 4.6 (1M context covers the corpus + diff at lower cost).
- **Investigate** -- Haiku unless `max` tier (which upgrades to the frontier).

`cheap` tier forces Haiku across the board and skips the docs pass entirely.
See **[Agent pipeline configuration](/docs/guides/alchemist-pipeline-configuration)**
for the per-project override surface, and the in-product **Model preferences**
panel for the per-tier caps.