---
title: "Diff Spec Versions"
method: GET
path: "/specs/diff"
tags: ["impact"]
---

# Diff Spec Versions

`GET /specs/diff`

## Request

- Base URL: `https://api.specproof.ai` (the document declares no server; this is the origin it was published from)
- URL: `https://api.specproof.ai/specs/diff`
- Auth: none declared

What changed normatively between two documents — two versions of a spec, or an RFC and
the RFC that obsoletes it.

## Query parameters

- `spec_base` string, nullable: e.g. '38331'
- `from_version` string, nullable: e.g. 'j20'
- `to_version` string, nullable: e.g. 'j30'
- `from_doc` integer, nullable: document id (unambiguous; use for MPEG/RFC)
- `to_doc` integer, nullable

## Headers

- `X-Org-Id` string, nullable
- `authorization` string

## Response `200`

Successful Response

- unknown

## Other responses

- `422`: Validation Error

---

[API](https://skmtc.dev/specproof/apis/specproof-portal-api.md) · [All operations](https://skmtc.dev/specproof/apis/specproof-portal-api/llms.txt) · [OpenAPI document](https://skmtc.dev/specproof/apis/specproof-portal-api/revisions/228b03caa929?raw)