[zorionarrillaga]

Proof of concept for #31. The SDK is generated, so this shows the change and its tests for carrying over to the generator.

What broke

HttpClient.request (src/vapi/core/http_client.py) retries every request up to 2 times by default:

• on any 5xx, 408 or 409 (_should_retry);
• on httpx.RemoteProtocolError, a connection dropped before the reply arrived.

calls.create() is POST /call, and campaigns.campaign_controller_create()/_v_2() are POST /campaign and POST /v2/campaign. All three place outbound phone calls. A 5xx or a dropped connection can come after Vapi has already dialled: a gateway timeout, or a proxy losing the reply. The API takes no idempotency key, so it can't tell the retry from a new request. The customer's phone rings a second time, the org pays for two calls, and the caller only gets back the second call id.

How it was reproduced

I used a local mock of POST /call on 127.0.0.1 only; no Vapi account or real API was involved. The mock records every POST as a dialled call and answers the first one with 502 Bad Gateway. One client.calls.create(assistant_id=..., phone_number_id=..., customer={"number": "+14155550199"}):

	PyPI 3.0.0	current main (01ebf69)	this branch
calls dialled by the mock	2 (call-1, call-2)	2 (call-1, call-2)	1 (call-1)
caller sees	success, call-2	success, call-2	ApiError 502

The PyPI 3.0.0 wheel's vapi/ package is byte-identical to main (diff -r is empty).

What changed

• core/http_client.py: a new helper, _places_calls(method, path). It is true for POST to call, campaign or v2/campaign. For those requests, in both the sync and the async client:
  • a status retry happens only on 429 (rate limited, so the call was never placed);
  • a connection-error retry happens only on httpx.ConnectError (the request was never sent). RemoteProtocolError is raised to the caller instead.
• Unchanged: every other request, including other POSTs such as assistants.create, keeps its current retries.
• tests/custom/test_call_placing_retries.py (new, 26 cases). It uses an in-memory httpx.MockTransport through the real Vapi/AsyncVapi clients:
  • calls.create, campaign create and campaign create v2 each hit the server exactly once after 500/502/503/504/408/409 (18 cases) and after a dropped connection (3);
  • calls.create is still retried on 429, and when the connection never opened;
  • calls.list() (GET) and assistants.create() (another POST) are still retried on 503;
  • the async calls.create is sent once after a 502, and once after a dropped connection.
• .fernignore: lists the new test, as for their other custom tests.

How it was tested

• New tests: 23 of 26 fail on current main (every "sent once" case). The 3 "still retried" cases pass on both. All 26 pass on the branch.
• Full suite (pytest -n 4 tests, Python 3.11.14): 105 passed, 4 skipped on the branch. HEAD gives 79 passed, 4 skipped.
• mypy . (1.13.0, their pin): Success: no issues found in 2512 source files.
• ruff check and ruff format --check (0.11.5, their pin): clean on both changed files.
• Real-socket mock repro: 2 dials before the change, 1 after (table above).
• Not run: the aiohttp-extra test job, and the Python 3.10/3.12-3.14 and pydantic v1 matrix. I ran Python 3.11 with pydantic 2 only.