diff --git a/.changeset/refactor-provider-agnostic-engine.md b/.changeset/refactor-provider-agnostic-engine.md
new file mode 100644
index 0000000..a70f2d0
--- /dev/null
+++ b/.changeset/refactor-provider-agnostic-engine.md
@@ -0,0 +1,35 @@
+---
+"@contentrain/mcp": minor
+---
+
+feat(mcp): provider-agnostic engine + HTTP transport + GitHub & GitLab providers
+
+The MCP package is now driven by a `RepoProvider` abstraction. All
+tools route through the same reader + writer + branch-ops contract,
+and the server accepts any provider (not just local disk).
+
+Shipped in this release:
+
+- **HTTP transport** (`@contentrain/mcp/server/http`) — Streamable
+  HTTP MCP transport with optional Bearer auth. Works against any
+  provider.
+- **GitHubProvider** (`@contentrain/mcp/providers/github`) — Octokit
+  over the Git Data + Repos APIs. `@octokit/rest` is an optional
+  peer dependency.
+- **GitLabProvider** (`@contentrain/mcp/providers/gitlab`) —
+  gitbeaker over the GitLab REST API. Supports gitlab.com and
+  self-hosted CE / EE. `@gitbeaker/rest` is an optional peer
+  dependency.
+- **Reader-backed reads everywhere** — `listModels`,
+  `readModel`, `countEntries`, `checkReferences`, and
+  `validateProject` now have reader overloads, so remote providers
+  get the same read-side behaviour (validation, reference
+  integrity, entry counts) as LocalProvider.
+- **Capability-gated tools** — normalize / scan / apply reject with
+  a uniform `capability_required` error on providers that do not
+  expose local disk access.
+
+No tool-surface changes. Stdio transport + LocalProvider remain the
+default and behave identically to the previous release.
+
+Bitbucket provider is on the roadmap; see the README.
diff --git a/README.md b/README.md
index ab330d0..d8635b6 100644
--- a/README.md
+++ b/README.md
@@ -146,6 +146,7 @@ Works with Nuxt, Next.js, Astro, SvelteKit, Vue, React, Node, Go, Python, Swift,
 - **Git-native** — every write goes through worktree isolation + review branches
 - **Normalize flow** — scan codebase for hardcoded strings → extract → create i18n-ready content → patch source files
 - **Local-first MCP** — 15 tools, stdio transport, works with Claude Code, Cursor, Windsurf, or any MCP client
+- **Provider-agnostic engine** — the same tool surface runs over a local worktree, GitHub, or GitLab (self-hosted included) with zero tool-code changes. HTTP transport available for remote drivers such as Studio.
 - **Canonical serialization** — sorted keys, deterministic output, clean git diffs, conflict-free parallel edits
 - **Agent rules & skills** — behavioral policies and step-by-step workflows ship as npm packages
 - **Serve UI** — local web dashboard for browsing models, content, validation, and normalize status
@@ -175,7 +176,7 @@ See [`AGENTS.md`](AGENTS.md) for the full skill catalog and agent guidance.
 
 | Package | npm | Role |
 |---|---|---|
-| [`@contentrain/mcp`](packages/mcp) | [![npm](https://img.shields.io/npm/v/%40contentrain%2Fmcp)](https://www.npmjs.com/package/@contentrain/mcp) | 15 MCP tools — content operations engine |
+| [`@contentrain/mcp`](packages/mcp) | [![npm](https://img.shields.io/npm/v/%40contentrain%2Fmcp)](https://www.npmjs.com/package/@contentrain/mcp) | 15 MCP tools + stdio / HTTP transport + Local / GitHub / GitLab providers |
 | [`contentrain`](packages/cli) | [![npm](https://img.shields.io/npm/v/contentrain)](https://www.npmjs.com/package/contentrain) | CLI + Serve UI + MCP stdio entrypoint |
 | [`@contentrain/query`](packages/sdk/js) | [![npm](https://img.shields.io/npm/v/%40contentrain%2Fquery)](https://www.npmjs.com/package/@contentrain/query) | Generated TypeScript query SDK |
 | [`@contentrain/types`](packages/types) | [![npm](https://img.shields.io/npm/v/%40contentrain%2Ftypes)](https://www.npmjs.com/package/@contentrain/types) | Shared type definitions + constants |
diff --git a/RELEASING.md b/RELEASING.md
index 1ccdedb..e9762e2 100644
--- a/RELEASING.md
+++ b/RELEASING.md
@@ -97,3 +97,17 @@ The GitHub `Release` workflow expects:
 - Do not maintain a custom release manifest.
 - Do not create manual monorepo-wide release tags.
 - Internal workspaces such as `docs` and `packages/cli/src/serve-ui` must remain `private: true`.
+
+## 🔌 `@contentrain/mcp` Optional Peer Dependencies
+
+`@contentrain/mcp` ships the remote providers as optional peers so
+consumers only install what they use:
+
+- `@octokit/rest` — required when using `GitHubProvider`.
+- `@gitbeaker/rest` — required when using `GitLabProvider`.
+
+Stdio + LocalProvider flows (the default) do not need either. When
+the MCP server is invoked with a provider whose peer is missing,
+the factory throws a helpful error pointing at the install command.
+Release audits do not need to bundle these peers — npm's
+`peerDependenciesMeta.optional: true` handles it.
diff --git a/packages/mcp/package.json b/packages/mcp/package.json
index e2b0375..66fe5cb 100644
--- a/packages/mcp/package.json
+++ b/packages/mcp/package.json
@@ -119,8 +119,8 @@
     "dist"
   ],
   "scripts": {
-    "build": "tsdown src/index.ts src/server.ts src/core/config.ts src/core/context.ts src/core/model-manager.ts src/core/content-manager.ts src/core/meta-manager.ts src/core/validator/index.ts src/core/scanner.ts src/core/scan-config.ts src/core/graph-builder.ts src/core/apply-manager.ts src/util/detect.ts src/util/fs.ts src/util/id.ts src/util/serializer.ts src/git/transaction.ts src/git/branch-lifecycle.ts src/templates/index.ts src/providers/github/index.ts src/providers/gitlab/index.ts src/server/http/index.ts --format esm --dts --external typescript",
-    "dev": "tsdown src/index.ts src/server.ts src/core/config.ts src/core/context.ts src/core/model-manager.ts src/core/content-manager.ts src/core/meta-manager.ts src/core/validator/index.ts src/core/scanner.ts src/core/scan-config.ts src/core/graph-builder.ts src/core/apply-manager.ts src/util/detect.ts src/util/fs.ts src/util/id.ts src/util/serializer.ts src/git/transaction.ts src/git/branch-lifecycle.ts src/templates/index.ts src/providers/github/index.ts src/providers/gitlab/index.ts src/server/http/index.ts --format esm --dts --external typescript --watch",
+    "build": "tsdown src/index.ts src/server.ts src/core/config.ts src/core/context.ts src/core/model-manager.ts src/core/content-manager.ts src/core/meta-manager.ts src/core/validator/index.ts src/core/scanner.ts src/core/scan-config.ts src/core/graph-builder.ts src/core/apply-manager.ts src/util/detect.ts src/util/fs.ts src/util/id.ts src/git/transaction.ts src/git/branch-lifecycle.ts src/templates/index.ts src/providers/github/index.ts src/providers/gitlab/index.ts src/server/http/index.ts --format esm --dts --external typescript",
+    "dev": "tsdown src/index.ts src/server.ts src/core/config.ts src/core/context.ts src/core/model-manager.ts src/core/content-manager.ts src/core/meta-manager.ts src/core/validator/index.ts src/core/scanner.ts src/core/scan-config.ts src/core/graph-builder.ts src/core/apply-manager.ts src/util/detect.ts src/util/fs.ts src/util/id.ts src/git/transaction.ts src/git/branch-lifecycle.ts src/templates/index.ts src/providers/github/index.ts src/providers/gitlab/index.ts src/server/http/index.ts --format esm --dts --external typescript --watch",
     "test": "vitest run",
     "typecheck": "tsc --noEmit",
     "clean": "rm -rf dist"
diff --git a/packages/mcp/src/util/fs.ts b/packages/mcp/src/util/fs.ts
index 1dafbde..db9b5df 100644
--- a/packages/mcp/src/util/fs.ts
+++ b/packages/mcp/src/util/fs.ts
@@ -1,6 +1,6 @@
 import { readFile, readdir, access, writeFile, mkdir } from 'node:fs/promises'
 import { join } from 'node:path'
-import { canonicalStringify } from './serializer.js'
+import { canonicalStringify } from '@contentrain/types'
 
 export async function pathExists(filePath: string): Promise<boolean> {
   try {
diff --git a/packages/mcp/src/util/serializer.ts b/packages/mcp/src/util/serializer.ts
deleted file mode 100644
index cdff60e..0000000
--- a/packages/mcp/src/util/serializer.ts
+++ /dev/null
@@ -1,5 +0,0 @@
-/**
- * Canonical JSON serialization — re-exported from @contentrain/types.
- * Kept as a module for backward compatibility with MCP subpath exports.
- */
-export { canonicalStringify, sortKeys } from '@contentrain/types'
diff --git a/packages/mcp/tests/util/serializer.test.ts b/packages/mcp/tests/util/serializer.test.ts
index 0241868..4e09492 100644
--- a/packages/mcp/tests/util/serializer.test.ts
+++ b/packages/mcp/tests/util/serializer.test.ts
@@ -1,5 +1,5 @@
 import { describe, expect, it } from 'vitest'
-import { canonicalStringify } from '../../src/util/serializer.js'
+import { canonicalStringify } from '@contentrain/types'
 
 describe('canonicalStringify', () => {
   it('sorts keys lexicographically', () => {