feat: layer code-driven plugin config over materialized file configs

crates/cli/src/config.rs

@@ -1,12 +1,12 @@
 // SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-use std::collections::HashSet;
 use std::net::SocketAddr;
-use std::path::{Path, PathBuf};
+use std::path::PathBuf;
 
 use axum::http::HeaderMap;
 use clap::{ArgGroup, Args, Parser, Subcommand, ValueEnum};
+use nemo_relay::plugin::{PluginError, load_plugin_config_files};
 use serde::Deserialize;
 use serde_json::Value;
 
@@ -744,31 +744,12 @@ fn load_plugin_toml_config_from_paths<I>(paths: I) -> Result<Option<PluginTomlCo
 where
     I: IntoIterator<Item = PathBuf>,
 {
-    let mut merged = toml::Value::Table(toml::map::Map::new());
-    let mut sources = Vec::new();
-    for path in paths {
-        if path.exists() {
-            let raw = std::fs::read_to_string(&path)?;
-            let parsed = raw
-                .parse::<toml::Table>()
-                .map(toml::Value::Table)
-                .map_err(|error| {
-                    CliError::Config(format!(
-                        "invalid plugin TOML in {}: {error}",
-                        path.display()
-                    ))
-                })?;
-            validate_plugin_toml_component_kinds(&path, &parsed)?;
-            merge_plugin_toml(&mut merged, parsed);
-            sources.push(path);
-        }
-    }
-    if sources.is_empty() {
-        return Ok(None);
-    }
-    let value = serde_json::to_value(merged)
-        .map_err(|error| CliError::Config(format!("invalid plugin TOML shape: {error}")))?;
-    Ok(Some(PluginTomlConfig { value, sources }))
+    // Delegate read/parse/merge to the shared core primitive (file precedence unchanged).
+    let resolved = load_plugin_config_files(paths).map_err(|err| match err {
+        PluginError::InvalidConfig(message) => CliError::Config(message),
+        other => CliError::Config(other.to_string()),
+    })?;
+    Ok(resolved.map(|(value, sources)| PluginTomlConfig { value, sources }))
 }
 
 fn apply_plugin_toml_config(
@@ -859,86 +840,6 @@ fn merge_toml(left: &mut toml::Value, right: toml::Value) {
     }
 }
 
-// Plugin TOML uses normal recursive TOML merging except for the top-level components array. Each
-// component is keyed by `kind`, so project/user plugins.toml files can add distinct plugin kinds or
-// override one plugin kind without restating every other component.
-fn merge_plugin_toml(left: &mut toml::Value, right: toml::Value) {
-    match (left, right) {
-        (toml::Value::Table(left), toml::Value::Table(right)) => {
-            for (key, value) in right {
-                match (key.as_str(), left.get_mut(&key)) {
-                    ("components", Some(existing)) => merge_plugin_components(existing, value),
-                    (_, Some(existing)) => merge_toml(existing, value),
-                    _ => {
-                        left.insert(key, value);
-                    }
-                }
-            }
-        }
-        (left, right) => *left = right,
-    }
-}
-
-fn merge_plugin_components(left: &mut toml::Value, right: toml::Value) {
-    let toml::Value::Array(left_components) = left else {
-        *left = right;
-        return;
-    };
-    let toml::Value::Array(right_components) = right else {
-        *left = right;
-        return;
-    };
-
-    for component in right_components {
-        let Some(kind) = component_kind(&component).map(str::to_owned) else {
-            left_components.push(component);
-            continue;
-        };
-        if let Some(existing) = left_components
-            .iter_mut()
-            .find(|candidate| component_kind(candidate) == Some(kind.as_str()))
-        {
-            merge_toml(existing, component);
-        } else {
-            left_components.push(component);
-        }
-    }
-}
-
-fn component_kind(component: &toml::Value) -> Option<&str> {
-    component
-        .as_table()
-        .and_then(|table| table.get("kind"))
-        .and_then(toml::Value::as_str)
-}
-
-fn validate_plugin_toml_component_kinds(path: &Path, value: &toml::Value) -> Result<(), CliError> {
-    let Some(components) = value.get("components").and_then(toml::Value::as_array) else {
-        return Ok(());
-    };
-    let mut seen = HashSet::new();
-    let mut duplicates = Vec::new();
-    for component in components {
-        let Some(kind) = component_kind(component) else {
-            continue;
-        };
-        if !seen.insert(kind.to_string()) {
-            duplicates.push(kind.to_string());
-        }
-    }
-    duplicates.sort();
-    duplicates.dedup();
-    if duplicates.is_empty() {
-        Ok(())
-    } else {
-        Err(CliError::Config(format!(
-            "duplicate plugin component kind in {}: {}; declare each kind once per plugins.toml",
-            path.display(),
-            duplicates.join(", ")
-        )))
-    }
-}
-
 fn has_config_toml_plugin_config(value: &toml::Value) -> bool {
     value
         .get("plugins")

crates/cli/src/server.rs

@@ -7,7 +7,7 @@ use axum::extract::State;
 use axum::http::HeaderMap;
 use axum::routing::{get, post};
 use axum::{Json, Router};
-use nemo_relay::plugin::{PluginConfig, clear_plugin_configuration, initialize_plugins};
+use nemo_relay::plugin::{PluginConfig, clear_plugin_configuration, initialize_plugins_exact};
 use nemo_relay_adaptive::plugin_component::register_adaptive_component;
 use reqwest::Client;
 use serde_json::Value;
@@ -157,9 +157,10 @@ impl PluginActivation {
         register_adaptive_component().map_err(|error| {
             CliError::Config(format!("adaptive plugin registration failed: {error}"))
         })?;
+        // Gateway already resolved its config; activate exactly (no re-discovery).
         let plugin_config: PluginConfig = serde_json::from_value(config)
             .map_err(|error| CliError::Config(format!("invalid plugin config: {error}")))?;
-        initialize_plugins(plugin_config)
+        initialize_plugins_exact(plugin_config)
             .await
             .map_err(|error| CliError::Config(format!("plugin activation failed: {error}")))?;
         Ok(Self { active: true })

crates/core/Cargo.toml

@@ -61,6 +61,7 @@ openinference = [
 uuid = { workspace = true, features = ["v7", "serde"] }
 serde = { version = "1", features = ["derive", "rc"] }
 serde_json = "1"
+toml = { version = "0.9" }
 schemars = { version = "0.8", optional = true }
 chrono = { version = "0.4", features = ["serde"] }
 bitflags = { version = "2", features = ["serde"] }
@@ -85,6 +86,7 @@ futures = "0.3"
 opentelemetry_sdk = { version = "0.31", default-features = false, features = ["trace", "testing"] }
 serde_json = "1"
 object_store = { version = "0.13", default-features = false, features = ["aws"] }
+tempfile = "3"
 
 [[test]]
 name = "codec_integration"