examples: serialize LLM calls via Semaphore (default 1) to dodge CAS busy-lock

fire_planner/examples/cli.py

@@ -52,20 +52,38 @@ async def ingest_subreddit(
     claude_bearer: str,
     client: httpx.AsyncClient,
     fx_rates: dict[str, Decimal],
+    llm_semaphore: asyncio.Semaphore | None = None,
 ) -> tuple[int, int]:
+    """Yield (inserted, skipped) counts for one (sub, when) bucket.
+
+    `llm_semaphore` serializes the LLM call across parallel sub-runs;
+    claude-agent-service's `/v1/chat/completions` has a single-flight
+    busy-lock, so 12 concurrent fan-outs trample each other. Default
+    None = no serialization (test path).
+    """
     inserted = 0
     skipped = 0
     async for post in fetch_top(reddit, sub, when, limit=limit):
         if not is_candidate(post):
             skipped += 1
             continue
-        extracted = await extract_with_fallback(
-            post,
-            llama_url=llama_url,
-            claude_url=claude_url,
-            claude_bearer=claude_bearer,
-            client=client,
-        )
+        if llm_semaphore is not None:
+            async with llm_semaphore:
+                extracted = await extract_with_fallback(
+                    post,
+                    llama_url=llama_url,
+                    claude_url=claude_url,
+                    claude_bearer=claude_bearer,
+                    client=client,
+                )
+        else:
+            extracted = await extract_with_fallback(
+                post,
+                llama_url=llama_url,
+                claude_url=claude_url,
+                claude_bearer=claude_bearer,
+                client=client,
+            )
         if extracted is None:
             log.info("dropping %s — both LLM tiers failed", post.reddit_id)
             skipped += 1
@@ -96,6 +114,13 @@ async def _ingest_all(
     claude_url = os.environ["CLAUDE_AGENT_SERVICE_URL"]
     claude_bearer = os.environ["CLAUDE_AGENT_BEARER"]
 
+    # Cap concurrent LLM calls across all sub-runs. claude-agent-service's
+    # /v1/chat/completions busy-locks (single-flight), so 12-sub fan-out
+    # otherwise loses 11 calls to 503. Default 1 = strict serial. Bump
+    # to 2-3 once the busy-lock is dropped for the chat endpoint.
+    llm_concurrency = int(os.environ.get("LLM_CONCURRENCY", "1"))
+    llm_semaphore = asyncio.Semaphore(llm_concurrency)
+
     async def _one(sub: str, when: TopWhen) -> tuple[int, int]:
         async with factory() as session, httpx.AsyncClient() as client:
             return await ingest_subreddit(
@@ -106,6 +131,7 @@ async def _ingest_all(
                 claude_bearer=claude_bearer,
                 client=client,
                 fx_rates=rates,
+                llm_semaphore=llm_semaphore,
             )
 
     tasks = [_one(s, w) for s in subs for w in when_list]