nexo-core

The runtime engine of Nexo — AgentRuntime, SessionManager, EventBus, Heartbeat, plus the LLM-facing tool registry and per-binding capability resolver. Every other crate in the workspace depends on this one.

This crate is part of Nexo — a multi-agent Rust framework with a NATS event bus, pluggable LLM providers (MiniMax, Anthropic, OpenAI-compat, Gemini, DeepSeek), per-agent credentials, MCP support, and channel plugins for WhatsApp, Telegram, Email, and Browser (CDP).

• Main repo: https://github.com/lordmacu/nexo-rs
• Runtime engine: this crate
• Public docs: https://lordmacu.github.io/nexo-rs/

What this crate does

Runtime

• AgentRuntime — owns every agent's lifecycle, intake hot path (per-binding rate limiter, pairing gate, credential resolver, redaction, link-understanding pre-fetch), and the agent loop that drives turns + dispatches tool calls.
• SessionManager — per-(agent_id, channel, instance, sender_id) session, debounced inbound + queue cap.
• AgentBehavior trait — what an agent actually does on each turn. The default LlmBehavior runs the LLM agent loop; custom behaviours plug in here for non-LLM agents.

Tools

• ToolRegistry + per-session filtered cache (Phase 18 hot-reload aware).
• Built-in tools — web_search, web_fetch (Phase 21 + W-2), taskflow, memory_*, session_logs, delegation, heartbeat, mcp.*, forge_memory_checkpoint / memory_history (workspace-git memory).
• ToolHandler trait for declaring new tools.

Memory + transcripts

• Transcript writer + FTS5 index for session_logs search.
• Redaction module — opt-in regex redactor with 6 built-in patterns (Bearer JWT, sk-/sk-ant- API keys, AWS access key, hex token, home path) + operator-defined extras.
• Workspace-git memory (Phase 10.9) — per-agent git repo for SOUL.md / MEMORY.md persistence, dreaming sweeps, forensics.

Capability resolution

• EffectiveBindingPolicy (Phase 16) — merges agent-level
  • binding-level policy at intake; cached on AgentContext for the turn.
• Per-agent credentials via nexo-auth resolver (Phase 17), wired into every tool that needs upstream API keys.
• Hot-reload (Phase 18) — ArcSwap<RuntimeSnapshot> for atomic config swap mid-session.

Phase 21 — link understanding

• LinkExtractor — fetches user-shared URLs, runs the readability-shaped extractor (Phase 21 L-2), caches in an LRU. Surfaces summaries via the # LINK CONTEXT block in the prompt.

Pairing (Phase 26)

• PairingGate consulted on every inbound before the per-sender rate limiter; PairingAdapterRegistry resolves the per-channel adapter for outbound challenge delivery.

Public API surface

This crate is large; the most operator-relevant types:

Install

[dependencies]
nexo-core = "0.1"

Documentation for this crate

• Architecture overview
• Agent runtime
• Transcripts (FTS + redaction)
• Link understanding
• Web fetch
• Per-agent credentials
• Hot-reload
• Agent-to-agent delegation recipe

License

Licensed under either of:

• Apache License, Version 2.0 (LICENSE-APACHE)
• MIT license (LICENSE-MIT)

at your option.