# Alchemist: Agent Pipeline Configuration

Tune the agent pipeline per project: models, effort, and per-phase overrides.

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Every build ticket runs through a pipeline of phases -- **plan**, **implement**,
**review**, **security**, and **docs** -- plus a read-only **investigate** phase
for research-only tickets. By default each phase uses a platform-tuned model
and reasoning setting. The **Agent pipeline configuration** panel (on a
project's settings page) lets you override any of that per project, per phase.

For each phase you can set:

- **Model** -- pin a specific model for that phase. Choose from the built-in
  catalog (Anthropic, OpenAI, xAI, Cerebras) or any OpenRouter model (pick
  from the fetched list or paste a custom `openrouter/…` id).
- **Reasoning** -- the **effort** and **thinking** level. Options are gated to
  what the chosen model supports, so you can't pick an invalid combination.
- **Additional instructions** -- extra guidance appended to that phase's
  prompt. This runs *after* the built-in framing, so it's safe -- the tool
  contract and required terminal actions are still enforced.
- **Prompt override** (advanced) -- replace the editable body of the phase's
  prompt entirely. Powerful, but you own the result; a bad override can break
  that phase's runs.

## How a phase resolves its settings

Settings resolve in priority order, highest first. The **Effective
configuration** table at the top of the panel shows what each phase will
actually use and *which* layer won (the source badge):

1. **project** -- your per-project override (this panel).
2. **env** -- a platform operator environment override.
3. **tier** -- the project's pipeline tier (e.g. a faster/cheaper tier).
4. **default** -- the platform's built-in default for that phase.

Leaving a field blank means that phase falls through to the next layer.
**Leaving everything blank is identical to the platform default** -- the panel
only changes behavior for the fields you set.

## Resetting

Each phase has a **Reset** button that clears all of its overrides and returns
it to the resolved default. Resetting one phase never touches the others.