Files
interactive-story/backend/app/providers/base.py
T
parththakkar106andClaude Opus 5 a408c7b6f7 Lay the prompt out so the endpoint can cache most of it
Prompt caching bills on a shared prefix: the endpoint reuses the request up
to the first byte that differs from last time and no further. The live
world-state block sat third from the top of the system message, so every turn
re-priced the instructions, the plot essentials and the whole story history
underneath it. The retrieved memories and the rewritten summary did it again.

Everything fixed is emitted first now, and everything that moves goes after
the history, ordered least-volatile first — which is also where recency serves
it best, the reasoning that already put the emit reminder last. The three tail
sections that are last for their own reasons stay last. The moved sections are
still charged to the token budget; only their position changed.

Two smaller halves of the same problem. OpenRouter serves a model from
whichever upstream is free and each upstream holds its own cache, so a
deepseek model now names deepseek as its preferred upstream — a preference,
not a restriction, so a turn still runs if that upstream is down. And the
endpoint's usage block is read back off the response and kept per attempt, so
the hit rate shows up in Insights and the debug log instead of being assumed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01DfMCsN1KBLsTqMkj5hSgrY
2026-08-23 06:31:30 +05:30

35 lines
1.1 KiB
Python

from abc import ABC, abstractmethod
from dataclasses import dataclass
from typing import AsyncIterator
@dataclass
class PromptParts:
"""Assembled context, provider-agnostic. Providers map this to their wire format."""
system: str # narrator prompt + AI instructions + memory
story: str # the story text so far (already token-budgeted)
class ProviderError(Exception):
"""User-presentable provider failure (connection refused, bad key, model not found…)."""
class Provider(ABC):
# The endpoint's own token accounting for the most recent call, when it
# reported any — notably `prompt_tokens_details.cached_tokens`, which is
# the only direct read on whether the prompt prefix is being cached.
# Callers read it after the call they made; one provider is built per
# request, so there is nothing to race.
last_usage: dict | None = None
@abstractmethod
def generate(
self,
parts: PromptParts,
*,
temperature: float,
max_tokens: int,
) -> AsyncIterator[tuple[str, str]]:
"""Yield ("text" | "reasoning", chunk) pairs. Raises ProviderError on failure."""