SombraX Agentic Core (sombrax_agentic_core)

sombrax_agentic_core (SAC) is a Rust library for building tool-using LLM agents with hookable execution, resilient completion loops, and strong context management.

It is designed for coding/automation workflows where context quality and local model stability matter as much as raw model capability. It was initially inspired by the RIG library and evolved toward stronger agent orchestration, context control, and local-model workflows.

What Problems It Solves

Core Capabilities

• Content-modifying hooks (pre_completion, post_completion, pre_tool_call, post_tool_call, filter_tools)
• Built-in tools for file/shell/web/task workflows
• MCP tool integration (McpToolSource)
• Cross-agent registry and shared context
• Provider-agnostic factory (build_agent) and provider-specific builders
• OpenTelemetry-friendly metrics/tracing integration

Context Management (Main Focus)

1) Token-Budget Optimization

Use any optimizer implementing ContextOptimizer:

• RecencyOptimizer
• PriorityOptimizer
• TruncationOptimizer

use sombrax_agentic_core::context::{OptimizationConfig, RecencyOptimizer};
use sombrax_agentic_core::providers::{OpenAIClientBuilder, OpenAIClientExt};
use sombrax_agentic_core::AgentBuilder;

let client = OpenAIClientBuilder::new("api-key").build();
let model = client.completion_model_adapter("gpt-4o-mini");

let agent = AgentBuilder::new(model)
    .context_optimizer(RecencyOptimizer::new())
    .optimization_config(
        OptimizationConfig::with_budget(8_192)
            .preserve_recent(12)
    )
    .build();

2) File-History Context Classification

For coding agents, FileContextHook tracks file operations and computes context decisions to avoid stale file history dominating prompts.

use sombrax_agentic_core::context::classification::FileContextHook;

let file_hook = FileContextHook::new();
// Attach file_hook to your AgentBuilder via .hook(file_hook.clone())

// Later, inspect optimization signals:
let optimization = file_hook.compute_optimization();
let files_needing_read = file_hook.files_needing_read();

// optimization.keep / optimization.drop / optimization.move_to_end

This is especially useful when an agent reads/edits the same file repeatedly in one session.

3) Request and Shared State

• HookContext: per-request mutable context across hooks
• SharedContext: session-scoped shared state for multi-agent flows

Local Models (Main Focus)

sombrax_agentic_core supports local inference without forcing cloud APIs.

Ollama (OpenAI-compatible endpoint)

use sombrax_agentic_core::providers::{OpenAIClientBuilder, OpenAIClientExt};
use sombrax_agentic_core::AgentBuilder;

let client = OpenAIClientBuilder::new("none")
    .base_url("http://localhost:11434/v1")
    .build();

let model = client.completion_model_adapter("qwen2.5-coder:7b");
let agent = AgentBuilder::new(model)
    .preamble("You are a precise Rust assistant.")
    .build();

LM Studio (anti-repetition controls)

use sombrax_agentic_core::providers::{LmStudioClientBuilder, LmStudioClientExt};
use sombrax_agentic_core::AgentBuilder;

let client = LmStudioClientBuilder::new()
    .base_url("http://localhost:1234/v1")
    .with_anti_loop_config()
    .with_anti_repetition_stops()
    .build();

let model = client.completion_model_adapter("qwen2.5-coder-14b-instruct");
let agent = AgentBuilder::new(model).build();

MLX-LM (Apple Silicon, chat-template aware)

use sombrax_agentic_core::providers::{MlxLmClientBuilder, MlxLmClientExt};
use sombrax_agentic_core::AgentBuilder;

let model_id = "mlx-community/Qwen2.5-Coder-7B-Instruct-4bit";

let client = MlxLmClientBuilder::new()
    .base_url("http://localhost:8080/v1")
    .auto_chat_template(model_id)
    .with_anti_loop_config()
    .with_chatml_stop_sequences()
    .with_anti_repetition_stops()
    .build();

let model = client.completion_model_adapter(model_id);
let agent = AgentBuilder::new(model).build();

Provider-Agnostic Agent Construction

Use LlmConfigLike + build_agent when you want one config path for both local and cloud models.

use sombrax_agentic_core::providers::{build_agent, LlmConfigLike};

struct AppLlmConfig {
    provider: String,
    url: String,
    model: String,
    api_key: Option<String>,
    temperature: Option<f64>,
}

impl LlmConfigLike for AppLlmConfig {
    fn provider(&self) -> &str { &self.provider }
    fn url(&self) -> &str { &self.url }
    fn model(&self) -> &str { &self.model }
    fn api_key(&self) -> Option<&str> { self.api_key.as_deref() }
    fn temperature(&self) -> Option<f64> { self.temperature }
}

# async fn run() -> Result<(), Box<dyn std::error::Error>> {
let cfg = AppLlmConfig {
    provider: "lmstudio".into(),
    url: "http://localhost:1234/v1".into(),
    model: "qwen2.5-coder-14b-instruct".into(),
    api_key: None,
    temperature: Some(0.3),
};

let agent = build_agent(&cfg, "You are a Rust assistant.", 4096, vec![]).await?;
let (content, stats) = agent.execute("Refactor this function.", &[]).await?;
println!("{}\n(total tokens: {})", content, stats.total_tokens());
# Ok(())
# }

Supported provider IDs include: openrouter, openai, anthropic, minimax, cerebras, zai, ollama, mlx, lmstudio.

Tools and Safety

sombrax_agentic_core::tools includes:

• File tools: ReadTool, WriteTool, EditTool, GlobTool, GrepTool
• Shell tool: BashTool (dangerous pattern rejection)
• Web tool: FetchTool
• Agent tools: TaskTool, TodoReadTool, TodoWriteTool

Tools run inside a ToolContext with workspace boundary checks.

MCP Integration

use sombrax_agentic_core::tool::McpToolSource;

# async fn run() -> Result<(), Box<dyn std::error::Error>> {
let source = McpToolSource::connect("http://localhost:3000/mcp").await?;
let _tools = source.discover().await?;
# Ok(())
# }

You can attach MCP tools to an agent via AgentBuilder::mcp_tools(source).await.

Installation

[dependencies]
sombrax_agentic_core = "0.1"
tokio = { version = "1", features = ["full"] }

Optional features: openai, anthropic, and runs (a pluggable pipeline/job runtime); full enables all three. Default build pulls in none of them.

Examples

Runnable, provider-agnostic examples live in examples/ (they default to a local Ollama, no API key required):

cargo run --example basic_agent       # one prompt, no tools
cargo run --example react_tool_agent  # custom Tool + agentic loop
cargo run --example guardrail_hook    # content-modifying hooks
cargo run --example panel_discussion  # multiple concurrent agents

See examples/README.md for the full list and the SAC_* environment variables that point them at any supported provider.

Development

cargo test --all-features
cargo clippy --all-features -- -D warnings
cargo fmt --check

Project Layout

• src/agent - agent runtime, loop execution, retries, wrapper
• src/context - hook/shared context + optimizers + file-history classification
• src/hook - hook trait, hook chain, built-in hooks
• src/providers - provider clients/adapters/builders (cloud + local)
• src/tools and src/tool - built-in tools and tool abstractions/MCP support

License

Licensed under either of

• Apache License, Version 2.0 (LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
• MIT license (LICENSE-MIT or http://opensource.org/licenses/MIT)

at your option.

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.