Erio is a Rust workspace for building an agent runtime with modular crates for LLM calls, tool execution, workflows, event handling, embeddings, and vector context storage.

• crates/core (erio-core): core types, messages, retry config, and shared errors.
• crates/tools (erio-tools): tool trait, schema helpers, registry, and tool execution primitives.
• crates/llm-client (erio-llm-client): provider abstraction and OpenAI adapter.
• crates/workflow (erio-workflow): DAG-based workflow engine and step orchestration.
• crates/event-bus (erio-event-bus): event model, event bus, and pluggable event sources.
• crates/embedding (erio-embedding): embedding engine abstractions and model integrations.
• crates/context-store (erio-context-store): vector-backed context storage and semantic retrieval.

• examples/react-agent: ReAct (Reason + Act) loop agent using LLM + Tools.
• examples/plan-execute-agent: Plan-then-execute agent using the workflow DAG engine.
• examples/multi-agent-chat: Multi-agent coordination pipeline via EventBus.
• examples/file-watcher-agent: Event-driven file summariser using EventBus + LLM.
• examples/rag-agent: Retrieval-augmented generation using ContextStore, Embedding, and LLM.

• Rust 1.93.0 or newer (workspace minimum)
• Cargo (ships with Rust)
• OPENAI_API_KEY and OPENAI_BASE_URL environment variables for LLM examples

erio-embedding uses a local EmbeddingGemma model. Model files are fetched at build time from public GitHub Release assets.

• Offline/custom path: set ERIO_MODEL_DIR to a directory containing:
  • embeddinggemma-300M-Q8_0.gguf
  • tokenizer.json
  • 2_Dense/model.safetensors
  • 3_Dense/model.safetensors
• For maintainers: the CI workflow publishes these assets and requires HF_TOKEN (after accepting the EmbeddingGemma license).

export OPENAI_API_KEY=sk-...
export OPENAI_BASE_URL=https://api.openai.com/v1

cargo run -p react-agent -- --prompt "Please uppercase the word hello"
cargo run -p plan-execute-agent -- --prompt "Add 10 and 20, then multiply by 3"
cargo run -p multi-agent-chat -- --prompt "Explain why Rust is great"
cargo run -p file-watcher-agent -- --files README.md
cargo run -p rag-agent -- --query "What is erio?" --documents README.md

Run from repository root:

cargo check --workspace
cargo test --workspace
cargo clippy --workspace --all-targets

• Apache-2.0