falsegreen-0.1.0 is not a library.

falsegreen

Independent verification for coding agents.

FalseGreen gives your AI coding agent an independent completion-authority loop. When the agent says "I'm done," FalseGreen runs your frozen acceptance criteria against an immutable source snapshot and tells the agent whether the work actually passes — instead of trusting the agent's own self-assessment.

This crate is the client shim — a tiny native binary that:

speaks STDIO MCP to your coding agent (Codex, Claude Code, Cursor, etc.)
authenticates to the FalseGreen service with your API key
forwards tool calls over HTTPS to mcp.falsegreen.com
manages device activation and credentials locally

The actual verification engine lives server-side. This binary contains no verification logic.

Install

cargo install falsegreen

Quick start

# 1. Log in (activates this device with your Polar license key)
falsegreen login --token YOUR_FALSEGREEN_KEY

# 2. Install into your agent
falsegreen install codex           # Codex CLI (STDIO)
falsegreen install codex-vscode    # Codex in VS Code (STDIO)
falsegreen install github-copilot  # GitHub Copilot in VS Code (HTTP)
falsegreen install claude-code     # Claude Code (HTTP)
falsegreen install opencode        # OpenCode (HTTP)
falsegreen install cursor          # Cursor (HTTP)

# 3. Verify
codex mcp list   # for Codex

Codex will now launch falsegreen mcp as a STDIO MCP server. HTTP-based agents (Copilot, Claude Code, OpenCode, Cursor) connect directly to mcp.falsegreen.com.

Tool	Purpose
`falsegreen_create_task`	Register a new task with a goal
`falsegreen_save_contract_draft`	Draft acceptance criteria
`falsegreen_validate_contract`	Validate the contract draft
`falsegreen_freeze_contract`	Freeze the contract (locks criteria + verifier)
`falsegreen_get_assignment`	Get compact immutable requirements
`falsegreen_check_completion`	Run the independent verifier
`falsegreen_get_status`	Check task status without verifying
`falsegreen_get_repair_feedback`	Get failure details from the last run
`falsegreen_get_contract_schema`	Get the JSON schema for contracts
`falsegreen_get_contract`	Get the frozen contract
`falsegreen_mark_unresolved`	Mark a task as unresolved

How it works

Coding agent (Codex, Claude Code, Cursor, ...)
  │
  │ STDIO MCP (JSON-RPC over stdin/stdout)
  ▼
falsegreen  ← this binary
  │
  │ HTTPS + X-API-KEY
  ▼
mcp.falsegreen.com
  │
  ├─ validate API key via Polar (cached 5 min)
  ├─ check per-tenant rate limit
  ├─ resolve tenant state directory
  └─ run verification engine
        │
        ├─ snapshot workspace source
        ├─ execute frozen acceptance criteria
        └─ return accepted / incomplete / unsafe

Commands

`falsegreen mcp`

Run the MCP server over STDIO. This is what Codex launches automatically. You rarely run this manually.

`falsegreen login --token <key>`

Activate this device and store credentials. Uses one of your device activation slots (2 by default, managed by Polar). The key is stored in ~/.config/falsegreen/credentials.toml.

`falsegreen logout`

Deactivate this device (frees the activation slot) and remove local credentials.

`falsegreen status`

Show authentication state, device activation ID, and API endpoint.

`falsegreen install <agent>`

Install FalseGreen into an agent's MCP configuration. Supported agents:

Agent	Command	Mode	Config file
Codex CLI	`falsegreen install codex`	STDIO	`~/.codex/config.toml`
Codex in VS Code	`falsegreen install codex-vscode`	STDIO	`.vscode/mcp.json`
GitHub Copilot	`falsegreen install github-copilot`	HTTP	`.vscode/mcp.json`
Claude Code	`falsegreen install claude-code`	HTTP	`.mcp.json`
OpenCode	`falsegreen install opencode`	HTTP	`opencode.json`
Cursor	`falsegreen install cursor`	HTTP	`.cursor/mcp.json`

STDIO agents spawn falsegreen mcp as a subprocess. HTTP agents connect directly to mcp.falsegreen.com with your X-API-KEY header.

Configuration

Environment variables

Variable	Default	Description
`FALSEGREEN_KEY`	(none)	API key (overrides stored credentials)
`FALSEGREEN_API_URL`	`https://mcp.falsegreen.com/v1/mcp`	MCP service URL

Credentials file

~/.config/falsegreen/credentials.toml:

token = "POLAR_xxxxxxxxxxxxxxxx"
activation_id = "uuid-of-device-activation"

Direct HTTP MCP (without the shim)

If your agent supports remote MCP servers, you can connect directly without installing the Rust binary:

URL: https://mcp.falsegreen.com/v1/mcp
Header: X-API-KEY: YOUR_FALSEGREEN_KEY

See the documentation for agent-specific setup guides.

License

Apache-2.0. See LICENSE for details.

falsegreen 0.1.0