Function resolve_vertex_ai_route

crates/openshell-server/src/inference.rs:549–656

Resolve a Vertex AI route given provider config, model, and bearer token.

(
    config: &std::collections::HashMap<String, String>,
    model_id: &str,
    route_name: &str,
    api_key: &str,
    profile: &openshell_core::inference::InferenceProviderProfile,
)

/// Resolve a Vertex AI route given provider config, model, and bearer token.
fn resolve_vertex_ai_route(
    config: &std::collections::HashMap<String, String>,
    model_id: &str,
    route_name: &str,
    api_key: &str,
    profile: &openshell_core::inference::InferenceProviderProfile,
) -> Result<RouterResolvedRoute, Status> {
    // Validate model_id early — it appears in URL paths for Anthropic routes
    // and in JSON request bodies for all routes. Rejecting path separators,
    // traversal segments, and control characters up front is defense-in-depth.
    validate_vertex_model_id(model_id)?;

    // Determine if this is an Anthropic model.
    // Explicit VERTEX_AI_PUBLISHER=anthropic overrides inference.
    // All non-Anthropic models route to the OpenAI-compatible endpoint.
    let explicit_publisher = config
        .get(VERTEX_AI_PUBLISHER_KEY)
        .map(String::as_str)
        .filter(|v| !v.trim().is_empty());

    let is_anthropic = explicit_publisher.map_or_else(
        || infer_vertex_publisher(model_id) == Some("anthropic"),
        |p| p.eq_ignore_ascii_case("anthropic"),
    );

    // Escape hatch: caller-supplied full base URL still uses the model-derived
    // protocol and path contract, but only for the OpenAI-compatible Vertex surface.
    // Anthropic-on-Vertex needs model-path shaping and body adaptation that a fully
    // caller-controlled URL cannot safely preserve.
    if let Some(base_url) = config
        .get(profile.base_url_config_keys[0])
        .or_else(|| config.get(profile.base_url_config_keys[1]))
        .map(String::as_str)
        .filter(|v| !v.trim().is_empty())
    {
        if is_anthropic {
            return Err(Status::invalid_argument(
                "Vertex AI base URL overrides are not supported for Anthropic models. \
                 Remove GOOGLE_VERTEX_AI_BASE_URL / VERTEX_AI_BASE_URL and configure \
                 VERTEX_AI_PROJECT_ID + VERTEX_AI_REGION instead."
                    .to_string(),
            ));
        }
        let base_url = validate_vertex_base_url(base_url)?;

        return Ok(build_vertex_route(
            route_name,
            base_url,
            model_id,
            api_key,
            vec!["openai_chat_completions".to_string()],
            profile,
            false,
            Some("/chat/completions".to_string()),
        ));
    }

    let project = required_vertex_config(config, VERTEX_AI_PROJECT_ID_KEY)?;