VectifyAI/PageIndex · error · PageIndexAPIError

model= sets both roles at once, so no slot can absorb it — n

Error message

model= sets both roles at once, so no slot can absorb it — name the model inside the slot ({"model": ...}) and use index_model= / chat_model= for a side written flat.

What it means

model= is a shorthand that sets both the index and chat roles, so it cannot coexist with the per-side slots index=/chat= — there is no slot left for it to absorb. The SDK requires you to spell per-side configuration explicitly.

Source

Thrown at pageindex/client.py:376

            )
        # Each side picks one spelling — its slot, or the flat arguments.
        # ``model`` sets every role, so it claims both sides.
        index_flat: dict[str, Any] = {
            name: value for name, value in
            (("api_key", api_key),
             ("index_model", index_model),
             ("summary_model", summary_model),
             ("index_backend", index_backend),
             ("storage_path", storage_path), ("model", model))
            if value is not None}
        chat_flat: dict[str, Any] = {
            name: value for name, value in
            (("chat_model", chat_model),
             ("retrieve_model", retrieve_model),
             ("chat_backend", chat_backend), ("model", model))
            if value is not None}
        if model is not None and (index is not None or chat is not None):
            raise PageIndexAPIError(
                "model= sets both roles at once, so no slot can absorb "
                'it — name the model inside the slot ({"model": ...}) '
                "and use index_model= / chat_model= for a side written "
                "flat.")
        if index is not None and index_flat:
            raise PageIndexAPIError(
                "index= and the flat index-side arguments "
                f"({', '.join(sorted(index_flat))}) are two spellings of "
                "the same thing — use one or the other.")
        if chat is not None and chat_flat:
            raise PageIndexAPIError(
                "chat= and the flat chat-side arguments "
                f"({', '.join(sorted(chat_flat))}) are two spellings of "
                "the same thing — use one or the other.")
        # ``mode=`` is a cross-check, not a spelling: it combines with
        # either spelling of the index side and must agree with it. The
        # pinned classes declare the side by class; their errors name the
        # class, never a mode= the user did not write.

View on GitHub (pinned to afb5e11976)

Solutions

1. Move the model into the slot: index={"model": ...} / chat={"model": ...}
2. Or use the flat per-side arguments index_model= / chat_model=
3. If both sides genuinely need the same model, set it separately per side

Example fix

# before
PageIndexClient(model="m", chat="cloud")
# after
PageIndexClient(index_model="m", chat="cloud")

assert not (model is not None and (index is not None or chat is not None)), "model= cannot combine with index=/chat="

When it happens

Trigger: PageIndexClient(model="m", index={...}) or PageIndexClient(model="m", chat="cloud").

Common situations: Starting with model= for a quick setup, then adding an index or chat slot as needs grow; merging example snippets that use different spellings.

Related errors

• chat declares mode "cloud" but carries ({keys}) — the manage
• chat is an empty string — pass a model name, or "cloud" for
• chat is an empty dict — chat takes "model" and "backend" (yo
• Unknown chat keys ({keys}) — chat takes "model" and "backend
• chat must be a string or a dict.

AI-assisted analysis of VectifyAI/PageIndex@afb5e11976 (2026-08-27). Data as JSON: /api/errors/157f4acd85f65225. Report an issue: GitHub.