layer0

Protocol layer for the Skelegent agentic AI architecture

Overview

layer0 defines the foundational protocol traits for composable agentic AI systems. It contains no implementations — only the contracts every agentic component must satisfy.

Four protocol traits + two cross-cutting interfaces:

Exports

Operator: Operator, OperatorInput, OperatorOutput, OperatorConfig, OperatorMetadata, SubDispatchRecord, ToolMetadata, ExitReason

Orchestrator: Orchestrator, QueryPayload

State: StateStore, StateReader, SearchResult

Environment: Environment, EnvironmentSpec

Middleware: DispatchMiddleware, StoreMiddleware, ExecMiddleware

Lifecycle: BudgetEvent, CompactionEvent, ObservableEvent

Effects: Effect, Scope, SignalPayload

Identity: OperatorId, WorkflowId, ScopeId, SessionId

Content: Content, ContentBlock

Errors: EnvError, OperatorError, OrchError, StateError

Misc: DurationMs, SecretAccessEvent, SecretAccessOutcome, SecretSource

Usage

[dependencies]
layer0 = "0.4"

Test utilities

[dev-dependencies]
layer0 = { version = "0.4", features = ["test-utils"] }

The test-utils feature exports in-memory implementations useful for testing downstream crates: EchoOperator, InMemoryStore, LocalEnvironment, LocalOrchestrator.

Implementing the Operator trait

use async_trait::async_trait;
use layer0::{Content, ExitReason, Operator, OperatorInput, OperatorOutput};
use layer0::error::OperatorError;

pub struct MyOperator;

#[async_trait]
impl Operator for MyOperator {
    async fn execute(&self, _input: OperatorInput) -> Result<OperatorOutput, OperatorError> {
        let msg = Content::text("done");
        Ok(OperatorOutput::new(msg, ExitReason::Complete))
    }
}

Part of the skelegent workspace

skelegent is a composable async agentic AI framework for Rust.