tirth8205/code-review-graph · error · RuntimeError

OpenAI API returned mixed indexed/unindexed data — refusing…

Error message

OpenAI API returned mixed indexed/unindexed data — refusing to misalign vectors.

What it means

If some returned embedding items have an integer `index` and others do not (or carry non-int index), there is no consistent rule to map vectors back to inputs: server order would misplace the indexed items. The provider therefore refuses with this RuntimeError instead of silently misaligning embeddings.

Solutions

Capture the raw response from the gateway and inspect which items lack index — that identifies the offending code path
Upgrade/fix the gateway to emit a uniform format: either all items indexed as a 0..N-1 permutation, or all unindexed with exact count
Route around the non-conforming gateway (use official OpenAI or another compliant endpoint) until fixed

Defensive patterns

Strategy: fallback

Validate before calling

# Canary against a new gateway: detect mixed-format responses cheaply
try:
    v = provider.embed(["a", "b"])
    assert len(v) == 2
except RuntimeError:
    raise RuntimeError("Gateway returns non-conforming embeddings responses; use another endpoint")

Try / catch

try:
    vecs = primary_gateway.embed(texts)
except RuntimeError as e:
    if "mixed indexed/unindexed" in str(e):
        vecs = official_openai.embed(texts)  # fall back to a spec-compliant endpoint
    else:
        raise

Prevention

Canary-test gateways with a 2-item embed before trusting them in production
Prefer official OpenAI/Voyage endpoints for correctness-critical embeddings
Keep a compliant fallback provider configured when using custom gateways

When it happens

Trigger: embed() against a gateway that mixes response formats — some items include data[i].index, others omit it or use a string index — e.g. a partially upgraded gateway or one that only indexes items it reordered.

Common situations: Homegrown OpenAI-compatible embedding servers, gateways stitching responses from multiple upstream shards, or proxies that rewrite some items and pass others through unchanged.

Related errors

AI-assisted analysis of tirth8205/code-review-graph@b58668751a (2026-08-28). Data as JSON: /api/errors/c43c7ccf64a60a9d. Report an issue: GitHub.

Appendix: source

Thrown at code_review_graph/embeddings.py:557

                    if len(set(indices)) != len(indices) or set(indices) != expected:
                        raise RuntimeError(
                            "OpenAI API returned malformed indices "
                            f"(got {indices}, expected permutation of "
                            f"0..{len(texts) - 1}) — refusing to misalign vectors."
                        )
                    data = sorted(data, key=lambda item: int(item["index"]))
                elif not any_has_index:
                    if len(data) != len(texts):
                        raise RuntimeError(
                            f"OpenAI API returned {len(data)} embeddings for "
                            f"{len(texts)} inputs with no index field — "
                            "refusing to misalign vectors."
                        )
                else:
                    # Mixed: some items have index, others don't (or carry
                    # non-int index). Server order would silently misplace
                    # the indexed items, so we refuse.
                    raise RuntimeError(
                        "OpenAI API returned mixed indexed/unindexed data — "
                        "refusing to misalign vectors."
                    )

                vectors = [item["embedding"] for item in data]
                if vectors and self._dimension is None:
                    self._dimension = len(vectors[0])
                return vectors

            except Exception as e:
                # Retryable = HTTP 429/5xx, network/timeout/TLS issues.
                # Non-retryable = HTTP 4xx (other), malformed responses,
                # misaligned data length — those are caller-side bugs that
                # will keep failing on retry.
                is_retryable = False
                if isinstance(e, urllib.error.HTTPError):
                    is_retryable = e.code == 429 or 500 <= e.code < 600
                elif isinstance(e, (

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