---
title: Changelog
description: Release history for the Seamline toolkit, covering Specdiff and Envlock.
url: https://pr-1-ee19382a0710.thally.app/changelog
---

# Changelog

Release history for the Seamline toolkit, covering Specdiff and Envlock.

### 0.1.0 -- 2026-09-17

Initial release of both Specdiff and Envlock. All six packages ship at version 0.1.0.

**Specdiff** -- Breaking-change detection for JSON Schema and OpenAPI:

- `@specdiff/core`: Zero-dependency diff engine with 45 detection rules covering JSON Schema drafts 04 through 2020-12 and OpenAPI 3.x. Direction-aware severity lets rules shift between breaking, warning, and info depending on request or response context. Output formatters produce plain text, JSON, and GitHub-flavoured Markdown.
- `@specdiff/cli`: Command-line tool for comparing two JSON or YAML documents. Supports configurable failure thresholds (`--fail-on`), rule and path filtering, and multiple output formats. Designed for CI pipelines with clear exit codes.
- `@specdiff/mcp`: MCP server exposing four tools -- `specdiff_compare`, `specdiff_explain_rule`, `specdiff_list_rules`, and `specdiff_format` -- so coding agents can detect breaking changes and format reports without leaving the editor.

**Envlock** -- Typed environment contracts for Node.js:

- `@envlock/core`: Schema definition with 10 field types (string, number, integer, boolean, port, url, enum, json, duration, list). Validation via `parseEnv` and `loadEnv`, a dotenv parser and formatter, `.env.example` rendering, strict diffing, secret redaction, and schema introspection. Zero runtime dependencies.
- `@envlock/cli`: Five commands for local and CI validation -- `check` validates against `process.env` or a dotenv file, `example` renders or verifies `.env.example`, `diff` performs a strict contract comparison, `inspect` lists all declared variables, and `init` scaffolds a starter config.
- `@envlock/mcp`: MCP server with five tools (`envlock_check`, `envlock_inspect`, `envlock_render_example`, `envlock_diff`, `envlock_explain_issue`) and a schema resource template (`envlock://schema/{schemaPath}`) for coding agents to validate and explore environment contracts.