tinyagents/

lib.rs

//! # TinyAgents — a recursive language-model (RLM) harness for Rust
//!
//! TinyAgents is a typed, durable runtime where **language models call models,
//! agents call agents, and graphs run graphs** — and where a model can author,
//! compile, and run the very workflow it is standing inside, all as inspectable,
//! checkpointed, policy-checked Rust.
//!
//! The "recursive" framing is the through-line of the whole crate, not a
//! footnote. It is architected around the execution model described in
//! "Recursive Language Models" (Alex L. Zhang, Tim Kraska, Omar Khattab, MIT
//! CSAIL, 2025; <https://arxiv.org/abs/2512.24601>): rather than stuffing
//! everything into one context window, a model treats long context as an
//! external *environment* it interacts with through a REPL — examining,
//! decomposing, and recursively calling sub-models over snippets. TinyAgents
//! brings that idea to Rust as a production-shaped harness (sub-model /
//! sub-agent / sub-graph calls as functions, persistent session values, depth
//! tracking, and trajectory/event logging). It is *inspired by and architected
//! around* the RLM execution model, not a reimplementation of the paper's
//! benchmarks.
//!
//! ## The five surfaces
//!
//! 1. **Harness** ([`harness`]) — provider-neutral model calls, typed tools,
//!    middleware, structured output, streaming, usage/cost, retry/limits, cache,
//!    memory/embeddings, sub-agents, steering, and a testkit.
//! 2. **Graph runtime** ([`graph`]) — LangGraph-style durable typed state
//!    graphs: [`START`]/[`END`], nodes, conditional routing, [`Command`]s,
//!    fan-out, reducers/channels, [`Checkpoint`]s, [`Interrupt`]s, subgraphs,
//!    streaming, and topology export.
//! 3. **Registry** ([`registry`]) — a named capability catalog (models, tools,
//!    agents, graphs, stores, middleware, policy) that `.rag`/`.ragsh` bind by
//!    name.
//! 4. **Expressive language `.rag`** ([`language`]) — a declarative,
//!    side-effect-free blueprint format that compiles (lexer → parser →
//!    compiler) into the same graph/harness runtime; the safe boundary for
//!    agent-authored plans.
//! 5. **REPL language `.ragsh`** ([`repl`]) — imperative, capability-bound
//!    interactive orchestration; the RLM/CodeAct loop surface.
//!
//! ## The recursion story
//!
//! Both `.rag` and `.ragsh` lower into the *same* [`graph`] + [`harness`] types
//! as hand-written Rust — a language whose programs are the runtime that
//! interprets them. A harness agent can be exposed *as a tool* to another agent
//! ([`SubAgent`], [`SubAgentTool`], [`SubAgentSession`]), so orchestration is
//! just a model calling a model; the runtime tracks parent/child run lineage and
//! enforces a recursion cap ([`TinyAgentsError::SubAgentDepth`]). At the deepest
//! level a model can emit a `.rag` blueprint that compiles through the same
//! registry-bound path as a human-authored file and runs on the same runtime the
//! model is already executing in (see `examples/openai_self_blueprint.rs`).
//!
//! ## Provider features
//!
//! The default build is offline and deterministic ([`harness::providers::MockModel`]).
//! Hosted and local providers (OpenAI plus the OpenAI-compatible endpoints for
//! Anthropic, Ollama, DeepSeek, Groq, xAI, OpenRouter, Together, and Mistral)
//! live behind the `openai` Cargo feature.
//!
//! ## Crate-root re-exports
//!
//! For discoverability the most-used types from each surface are re-exported at
//! the crate root, grouped below by surface ([`error`], [`registry`],
//! [`language`], [`harness`], and [`graph`]).

pub mod error;
pub mod graph;
pub mod harness;
pub mod language;
pub mod registry;
pub mod repl;

// --- Error: the crate-wide error type and `Result` alias ---
pub use error::{Result, TinyAgentsError};

// --- Registry: named capability catalog (.rag/.ragsh binding by name) ---
pub use registry::{CapabilityRegistry, ComponentId, ComponentKind, ComponentMetadata};

// --- Language: registry → blueprint binding façade ---
// The strict, registry-backed entry points the REPL and orchestrators use to
// turn `.rag`/`.ragsh` source into validated blueprints. `compile_source` runs
// parse -> compile -> registry-bind in one call.
pub use language::compiler::{
    CapabilityResolver, bind_capabilities, bind_capabilities_with_registry, compile, compile_source,
};
pub use language::types::Blueprint;

// --- Harness: embeddings + retrieval ---
pub use harness::embeddings::{
    EmbeddingModel, InMemoryVectorStore, MockEmbeddingModel, Retriever, ScoredDoc, VectorStore,
    cosine_similarity,
};

// --- Harness: first-class sub-agents (agent-calling-agent composition) ---
pub use harness::subagent::{SubAgent, SubAgentSession, SubAgentTool};

// --- Harness: orchestrator → sub-agent steering ---
pub use harness::steering::{
    SteeringCommand, SteeringCommandKind, SteeringHandle, SteeringOutcome, SteeringPolicy,
};

// --- Cooperative run cancellation ---
pub use harness::cancel::CancellationToken;

// --- Harness: durable observability (journals, status stores, sinks) ---
pub use harness::observability::{
    AgentObservation, FanOutSink, HarnessEventJournal, HarnessStatusStore, InMemoryEventJournal,
    InMemoryStatusStore, JournalSink, JsonlSink, RedactingSink, StoreEventJournal,
};

// --- Graph: durable execution model (LangGraph-style) ---
// Re-exported with explicit names so the durable API is discoverable at the
// crate root. The `harness::stream::StreamMode` and `graph::stream::StreamMode`
// types intentionally stay behind their module paths to avoid a name clash.
#[cfg(feature = "sqlite")]
pub use graph::SqliteCheckpointer;
pub use graph::{
    Checkpoint, CheckpointConfig, CheckpointMetadata, CheckpointSource, CheckpointTuple,
    Checkpointer, ChildRun, ChildRunSink, ClosureReducer, ClosureStateReducer, Command,
    CompiledGraph, DurabilityMode, END, FileCheckpointer, ForkId, GraphBuilder, GraphDefaults,
    GraphEvent, GraphExecution, GraphRunStatus, InMemoryCheckpointer, Interrupt, NodeContext,
    NodeResult, RecursionFrame, RecursionPolicy, RecursionStack, Reducer, ResumeTarget, Route,
    RouteTarget, RunTree, START, StateReducer, StateSnapshot,
};

// --- Graph: sub-agent nodes (delegate a graph step to a registered agent) ---
pub use graph::{
    HarnessAgent, HarnessSubAgent, SubAgentBudget, SubAgentInput, SubAgentNode, SubAgentOutput,
    SubAgentPolicy, subagent_node,
};

// --- Graph: channel-per-field state model (additive; see state-channels.md) ---
// An opt-in alternative to the monolithic State + StateReducer path: state is
// split into independently-merged named channels.
pub use graph::{
    Barrier, BinaryAggregate, Channel, ChannelSet, ChannelState, ChannelUpdate, Delta, Ephemeral,
    LastValue, Messages, NamedBarrier, Topic, Untracked,
};

// --- Graph: durable observability (journals, status stores, journaling sink) ---
// Names are graph-prefixed so they never collide with the harness observability
// re-exports above.
pub use graph::{
    GraphEventJournal, GraphObservation, GraphStatusStore, InMemoryGraphEventJournal,
    InMemoryGraphStatusStore, JournalGraphSink, StoreGraphEventJournal,
};

// --- Graph: export / visualization ---
// Topology types are surfaced at the crate root; the `to_json`/`to_mermaid`
// free functions stay behind `graph::export::` to avoid generic-name clashes.
pub use graph::{
    ChannelInfo, ConditionalEdgeInfo, EdgeInfo, GraphPolicySummary, GraphTopology, NodeInfo,
    NodePolicySummary, RouteInfo, ValidationReport, WaitingEdgeInfo,
};