## Many-shot watcher


## retrain.manyshot.build_exemplar_system()


The byte-constant many-shot system prompt: seeded demonstrations under `budget_chars`.


Usage

``` python
retrain.manyshot.build_exemplar_system(
    rows, *, budget_chars=EXEMPLAR_BUDGET, seed=SEED
)
```


Walks `rows` in a seeded permutation, greedily keeping each demonstration whose body fits the remaining budget and skipping any that would overflow, then wraps them in the fixed instruction frame. Deterministic in `(rows, budget_chars, seed)` and byte-identical every call, so [score_frame()](many-shot-watcher.md#cc_steer.retrain.manyshot.score_frame) can reuse one prefix across every batch and hit the provider's prompt cache.


## retrain.manyshot.score_frame()


Score the frozen frame with a cached many-shot prefix and store its `P(NO_STEER)`.


Usage

``` python
retrain.manyshot.score_frame(
    frame,
    exemplars,
    *,
    version,
    model,
    budget_chars=EXEMPLAR_BUDGET,
    batch_size=BATCH_SIZE,
    seed=SEED,
    eval_root=None,
    max_cache_miss_streak=MAX_CACHE_MISS_STREAK
)
```


Builds one byte-constant exemplar system prompt from `exemplars` and scores the frame in `batch_size` batches against it, so every batch after the first reads the prefix from the provider's prompt cache instead of re-sending it. Each batch's per-context steer probabilities become `P(NO_STEER) = 1 - p`; the whole frame's probabilities and their fire AUC land through `~cc_steer.retrain.evalset.write_probs()`, paired-comparable with any trained watcher on the same frame.


#### Parameters


`frame: `<a href="retraining.html#cc_steer.retrain.evalset.EvalFrame" class="gdls-link gdls-code"><code>EvalFrame</code></a>  
The frozen eval frame to score.

`exemplars: Sequence[WatcherRow]`  
The demonstration pool the system prefix draws from (watcher train rows).

`version: str`  
The registry version label the stored probs are keyed under.

`model: str`  
The frontier model to run, for example `claude-opus-4-6`.

`budget_chars: int = EXEMPLAR_BUDGET`    
Character budget for the exemplar prefix.

`batch_size: int = BATCH_SIZE`    
Frame rows scored per cached call.

`seed: int = SEED`    
Seed for the exemplar shuffle.

`eval_root: Path | None = None`  
Eval root override; defaults to `~/.cc-steer/eval`.

`max_cache_miss_streak: int = MAX_CACHE_MISS_STREAK`    
Consecutive post-warmup cache misses that abort the pass.


#### Returns


`Path`  
The path the per-row probabilities were written to.


#### Raises


`ManyShotError`  
When a batch reply is unparseable or the prompt cache stays cold for `max_cache_miss_streak` batches in a row.