Get By Predicate

Retrieves records from a vector store that satisfy a given predicate filter. Supports filtered semantic queries where embeddings must meet metadata-based conditions in addition to similarity searches.

Source Code Example

Click to expand

use ahnlich_client_rs::ai::AiClient;
use ahnlich_client_rs::error::AhnlichError;
use ahnlich_client_rs::prelude::StoreName;
use ahnlich_types::{
    ai::query::GetPred,
    predicates::{Predicate, PredicateCondition, predicate::Kind as PredicateKind, predicate_condition::Kind as PredicateConditionKind, Equals},
    metadata::{MetadataValue, metadata_value::Value as MValue},
};
use tokio;


#[tokio::main]
async fn main() -> Result<(), AhnlichError> {
    // Connect to AI server
    let ai_client = AiClient::new("http://127.0.0.1:1370".to_string())
        .await
        .expect("Failed to connect AI client");


    // Define store and metadata condition
    let store_name = StoreName { value: "Deven Kicks".to_string() };
    let matching_metadatakey = "Brand".to_string();
    let matching_metadatavalue = MetadataValue { value: Some(MValue::RawString("Nike".into())) };


    // Build predicate condition
    let condition = PredicateCondition {
        kind: Some(PredicateConditionKind::Value(Predicate {
            kind: Some(PredicateKind::Equals(Equals {
                key: matching_metadatakey.clone(),
                value: Some(matching_metadatavalue.clone()),
            })),
        })),
    };


    let get_pred_params = GetPred {
        store: store_name.value.clone(),
        condition: Some(condition),
    };


    // Call get_pred
    let response = ai_client.get_pred(get_pred_params, None).await?;


    println!("Matching entries:");
    for entry in response.entries {
        println!("{:?}", entry);
    }


    Ok(())
}

Parameters

• params: GetPred — Contains the store name and predicate expression used to filter records.

• tracing_id: Option<String> — Optional trace parent ID for distributed tracing and observability.

Returns

• Ok(Get) — A collection of records (embeddings + metadata) that satisfy the predicate filter.

• Err(AhnlichError) — Returned if the store cannot be queried, the predicate is invalid, or the request fails.

Behavior

• Constructs a tonic::Request from the GetPred parameters.

• Attaches tracing metadata when provided.

• Calls the AI service’s get_pred RPC endpoint.

• Waits for the server response and extracts the result.

• Returns the retrieved records packaged in a Get object.