mem0ai/mem0 · error · ValueError

Invalid threshold: {threshold}. Must be between 0 and 1 (inc

Error message

Invalid threshold: {threshold}. Must be between 0 and 1 (inclusive).

What it means

Raised by the private helper _validate_search_params in the OSS Memory SDK when the 'threshold' argument passed to Memory.search() (or any API that forwards to it) is a number outside the inclusive range [0, 1]. The threshold controls the minimum similarity score for returned memories, so values below 0 or above 1 are meaningless for cosine-similarity scoring and are rejected before any embedding or vector-store call is made. It is a plain ValueError raised during argument validation, so no network or LLM cost is incurred.

Source

Thrown at mem0/memory/main.py:227

    return trimmed


def _validate_search_params(threshold: Optional[float] = None, top_k: Optional[int] = None) -> None:
    """
    Validates search parameters.

    Args:
        threshold: Similarity threshold (must be between 0 and 1)
        top_k: Number of results to return (must be non-negative integer)

    Raises:
        ValueError: If threshold or top_k are invalid
    """
    if threshold is not None:
        if not isinstance(threshold, (int, float)):
            raise ValueError("threshold must be a valid number")
        if threshold < 0 or threshold > 1:
            raise ValueError(
                f"Invalid threshold: {threshold}. Must be between 0 and 1 (inclusive)."
            )
    if top_k is not None:
        if not isinstance(top_k, int) or isinstance(top_k, bool):
            raise ValueError("top_k must be a valid integer")
        if top_k < 0:
            raise ValueError(
                f"Invalid top_k: {top_k}. Must be a non-negative integer."
            )


def _validate_and_trim_search_query(query: str) -> str:
    """
    Validates and normalizes a search query before embedding/vector search.

    Raises:
        ValueError: If query is not a string or is empty/whitespace-only.
    """

View on GitHub (pinned to 001c235229)

Solutions

1. Change the threshold to a float between 0 and 1 inclusive (e.g. 0.75 instead of 75, or 0.4 instead of a distance like 1.5).
2. If you intended a percentage, divide by 100 before passing it.
3. If you actually wanted a distance-based cutoff, remember mem0 OSS uses similarity scores; lower threshold = more results, and pass None to use the default.
4. Leave threshold=None to accept the SDK default instead of guessing a value.

Example fix

# before
results = m.search("python tips", filters={"user_id": "u1"}, threshold=75)

# after
results = m.search("python tips", filters={"user_id": "u1"}, threshold=0.75)

def validate_threshold(t):
    if t is None:
        return None
    if not isinstance(t, (int, float)) or isinstance(t, bool):
        raise ValueError("threshold must be a number")
    if not 0.0 <= t <= 1.0:
        raise ValueError(f"threshold {t} out of range [0,1]; did you mean {t/100}?")
    return float(t)

threshold = validate_threshold(cfg.get("threshold"))
results = m.search(q, filters=f, threshold=threshold)

def is_valid_threshold(t) -> bool:
    return t is None or (isinstance(t, (int, float)) and not isinstance(t, bool) and 0.0 <= t <= 1.0)

When it happens

Trigger: Calling m.search(query='...', filters={'user_id':'u1'}, threshold=1.2), threshold=-0.01, or threshold=5. Also triggered when threshold is computed dynamically (e.g. a percentage like 75 instead of 0.75) or read from config/env as a percentage. Note booleans are accepted here because bool is a subclass of int and only the range check applies (True==1 passes, False==0 passes).

Common situations: Developers porting code from another vector DB API where thresholds are 0-100 percentages; mixing up 'top_k' and 'threshold' argument order; copying a score threshold from a different similarity metric (e.g. a distance threshold like 1.5 for L2 distance, which is valid in Qdrant/Pinecone but not here).

Related errors

• threshold must be a valid number
• Invalid threshold: ${threshold}. Must be between 0 and 1 (in
• topK must be a valid integer
• Invalid topK: ${topK}. Must be a non-negative integer.
• filters must contain at least one of: user_id, agent_id, run

AI-assisted analysis of mem0ai/mem0@001c235229 (2026-08-15). Data as JSON: /api/errors/1304013314d25c62. Report an issue: GitHub.