HKUDS/Vibe-Trading · error · ValueError

unexpected market payload shape

Error message

unexpected market payload shape

What it means

Raised by prediction_market_tool._resolve_history_token when a Gamma markets API lookup by identifier returns a non-dict payload (e.g. a list, string, or null). The resolver expects a single market JSON object; anything else means the identifier did not resolve to one market (404 HTML/error body, array response, or empty body) and the shape is unexpected.

Source

Thrown at agent/src/tools/prediction_market_tool.py:803

    Returns:
        ``(token_id, context)`` where context carries whatever identifying
        metadata was resolved along the way.

    Raises:
        ValueError: The id cannot be resolved to an outcome token.
        requests.RequestException: Propagated from the HTTP layer.
    """
    if _is_clob_token_id(identifier):
        return identifier, {"clob_token_id": identifier}

    if identifier.lower().startswith("0x"):
        payload = _get_json(f"{_CLOB_MARKETS_URL}/{identifier}", host_key=_CLOB_HOST_KEY)
        raw = _clob_market_to_gamma_shape(payload) if isinstance(payload, dict) else {}
    else:
        raw = _get_json(f"{_GAMMA_MARKETS_URL}/{identifier}", host_key=_GAMMA_HOST_KEY)
        if not isinstance(raw, dict):
            raise ValueError("unexpected market payload shape")

    names = [str(n) for n in _json_list(raw.get("outcomes"))]
    tokens = [str(t) for t in _json_list(raw.get("clobTokenIds"))]
    if not tokens:
        raise ValueError("market exposes no CLOB outcome tokens")

    index = 0
    if outcome is not None:
        matches = [i for i, n in enumerate(names) if n.lower() == outcome.lower()]
        if not matches:
            raise ValueError(f"outcome '{outcome}' not in {names}")
        index = matches[0]
    if index >= len(tokens):
        raise ValueError("outcome has no matching CLOB token")

    return tokens[index], {
        "market_id": str(raw.get("id")) if raw.get("id") is not None else None,
        "question": raw.get("question"),

View on GitHub (pinned to 80ffdda44c)

Solutions

1. Confirm the identifier is the correct Gamma market slug/UUID (not the CLOB 0x id, which uses the other branch)
2. Check the raw GET response for that identifier with curl to see the actual payload type
3. Verify _GAMMA_HOST_KEY host configuration matches the expected Gamma deployment
4. Handle this as a not-found condition: re-resolve the market slug before retrying

try:
    token, meta = _resolve_history_token(identifier, outcome)
except ValueError as e:
    if "unexpected market payload shape" in str(e):
        # treat as not-found: re-resolve slug or surface a clean 404 to the user
        raise MarketNotFound(identifier) from e

When it happens

Trigger: Fetching a Gamma market by a non-hex identifier that doesn't exist (API returns an error body or null); passing a slug that resolves to a redirect/list payload; the Gamma endpoint changing its response contract for single-market GETs.

Common situations: Wrong or stale market IDs/slug copied from docs; environment pointing at a different Gamma host whose single-market endpoint behaves differently; API contract changes after a Polymarket release.

Related errors

• market exposes no CLOB outcome tokens
• outcome '{outcome}' not in {names}
• outcome has no matching CLOB token
• invalid JSON response: {exc}

AI-assisted analysis of HKUDS/Vibe-Trading@80ffdda44c (2026-08-28). Data as JSON: /api/errors/3c32f47a37f71fd6. Report an issue: GitHub.