---
title: Seamline Toolkit
description: Ship API and configuration contracts with confidence using Specdiff and Envlock.
url: https://pr-1-7cfcfe393d12.thally.app/
---

# Seamline Toolkit

Ship API and configuration contracts with confidence using Specdiff and Envlock.

## Two tools, one goal

Seamline helps teams catch contract drift — in API schemas and in environment
configuration — before it reaches production.

#### [Specdiff](/specdiff-overview)

    Compare JSON Schema and OpenAPI documents. Every change is classified as
    breaking, warning, or info with a stable rule code, JSON-pointer path, and
    human-readable message.

#### [Envlock](/envlock-overview)

    Declare the environment variables your app needs once, then validate, type,
    document, diff, and redact them everywhere — at startup, in CI, and from
    coding agents.

## Use from anywhere

Both tools ship as a library, a CLI, and an MCP server so they fit into
application code, CI pipelines, and AI-assisted workflows.

#### Library

    Import `@specdiff/core` or `@envlock/core` for programmatic access with full
    TypeScript types.

#### CLI

    Run `specdiff` or `envlock` in a terminal or CI job. Exit codes map directly
    to pass/fail gates.

#### MCP Server

    Connect `@specdiff/mcp` or `@envlock/mcp` to any MCP-compatible coding
    agent for tool-assisted contract checks.