Eva

A coding harness built in Elixir, inspired by tau.

Work in progress — things may move, break, and change.

Idea

Current ideas, subject to change.

Architecture

Eva is a distributed coding agent platform. It ships with a default terminal agent harness powered by ex_ratatui + BYO-FE, with a modular architecture that lets you swap out providers and frontends.

Feature Checklist

• Distributed architecture
  • How do we discover & connect to Evas in different machines?
    • Tailscale?
      • Most of the work is already done(Security, Discovery & Connection)
      • Connections & Creds management
    • Iroh?
  • Splittable Architecture. Harness or API processes can live on another machines. or even tools.
    • Tool call to connected Evas.
  • At what point do we handle external node messages?
    • Split between:
      • Providers
      • Harness
• Provider
  • Opencode go
  • LMStudio
  • Completions API
  • Handle envs & config
  • Responses API
  • Switch providers at runtime
• Storage
  • Directory(sessions/index)
  • Move to sqlite?
• Agent Harness
  • The agent loop
  • Handling distributed node messages
  • Context
    • Sessions
    • Memory
    • Compaction
    • Skills
    • Prompt templates
    • AGENTS.md
    • Diagnostics
  • Prompts
    • Follow-up
    • Queue
    • Assembling prompts
  • Tools
    • Tool calls
      • Approvals
      • Elixir native?
      • read
      • write
      • edit
      • bash
        • Explore just-bash(https://github.com/elixir-ai-tools/just_bash) for bash interpreter(& virtual FS)
      • Q/A
      • Web search
        • Using exa MCP
        • Brave search API
      • Web fetch
        • Using exa MCP (responds in markdown)
        • In house (using finch/req) with multiple output format: markdown, html
          • JS rendered pages? Should be a lightweight implementation
  • Subagents
    • As an extension
    • Modes or Characters(?)(like amp)
      • Deep
      • Librarian
      • Oracle
  • UI agnostic commands layer
  • Extensions
    • Remote extensions
    • Support https://agent-plugins.org/
    • Perhpas "sharing" as an extension
  • MCP
    • As an extension
    • Support latest spec (it is basically REST)
    • Stdio
    • Http
    • Tool calls
    • System prompts
    • Resources
    • Notifications
    • Toggle servers on/off (per-session override or persisted to mcp.json)
    • Requests from MCPs
  • Ability to modify itself
    • With Hot reload?
  • Sharing(login?)
    • Atproto
      • PDS as sync layer(inspired by tiles.run)?
    • (Fun idea): Indieweb?
  • (Experiment): Explore with mob as distributed node connection?
• TUI (ex_ratatui) + BYO-FE
  • Slash commands (/usage, /providers, /login, /logout, ...)
  • Pretty lil animations
• catalogue.yml or something for list of providers
• Sandboxing
  • The whole agent or code executions only?
  • https://microsandbox.dev/
  • Firecracker? https://github.com/harmont-dev/hyper
• Observability
  • Number of sessions, time taken, total token usage, failures etc.
• Remote node connection cookie sharing
  • Make it secure. Pluggable service which nodes can consult to get a cookie?
• Explore https://github.com/elixir-vibe/vibe for further stuff
  • https://x.com/davydog187/status/2075320738261659775

What Sets It Apart

• Distributed by default — designed for multi-node setups from the start.
• Elixir-native — fault tolerance, hot code reloading, and concurrency via the BEAM.
• BYO-FE — bring your own frontend; the default TUI is built with ex_ratatui but you can swap in anything.
• Modular — providers, tools, and agents are pluggable components.