FAIR — Fast AI Relay

One file. Zero dependencies. A coding agent that fits in your head.

Requirements

Bun — curl -fsSL https://bun.sh/install | bash

Run

bun fair.ts              # first run → auto-configure
bun fair.ts --configure  # force reconfigure

Config is saved to .fair/config.json. Once set, it persists across sessions. Use --configure to update or /configure inside a session.

Commands

Type / then press Tab to see suggestions. Type /c + Tab to cycle through matching commands.

Command	What it does
/configure	Set API key, model, budget, context limit
/config	Show current config
/model <name>	Quick-switch model (saves to config)
/budget <n>	Set budget alert
/clear	Clear conversation history
/save	Save session to disk
/compact	Summarize old messages manually
/image <path>	Attach image to next prompt
/help	Show all commands
/quit	Exit and save

Resume a Session

bun fair.ts --resume <session-id>

Session files live in .fair/sessions/.

Tests

bun test

Covers config, tokenizer, all 4 tools, provider SSE parsing, session save/load, auto-compaction, streaming markdown renderer, and reasoning_content handling.

Files

fair.ts        # 907 lines — the entire harness
fair.test.ts   # 693 lines — 60 tests
package.json   # 9 lines

Config File

.fair/config.json:

{
  "apiKey": "sk-...",
  "apiBase": "https://api.openai.com/v1",
  "model": "gpt-4o-mini",
  "budget": 10,
  "contextLimit": 128000
}

Features

• Single file — read the whole thing in 15 minutes
• Zero dependencies — only needs Bun
• Native TypeScript — no build step
• Minimal TUI — 256-color soft palette, clean indentation, no boxes
• Streaming renderer — plain-text formatting with inline bold, code, headers, lists, and code blocks
• Streaming — assistant text streams live; tools show minimal indented output
• Auto-compaction — summarizes old messages at 80% context
• Cost tracking — running total in the status bar with light border lines, color-coded by budget
• Image support — /image path.png attaches to next prompt
• Session persistence — JSONL format, resume anytime
• Input history — ↑/↓ arrows recall previous prompts, persisted to .fair/history
• Tab completion — / + Tab shows all commands
• Safety — blocks rm -rf / and sudo rm