feat: Add OFREP flag evaluation tool (#4)

* feat: Add OpenFeature Remote Evaluation Protocol tool

Co-authored-by: jonathan <jonathan@taplytics.com>

* fix: build of OFREP tool import and types

* chore: extract OFREP API calling logic into separate function

* chore: README.md updates

* fix: update README config example and standardize registerOfrepTools API

* feat: add vitest for OFREP tests

* feat: add new vitest files

* feat: add GH action to build / test

* chore: cleanup

* chore: update tests, fix error responses

* test: mock fetch using Response in ofrepTools tests

---------

Co-authored-by: Cursor Agent <cursoragent@cursor.com>

Author: jonathannorris

.github/workflows/ci.yml

@@ -0,0 +1,33 @@
+name: CI
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  build-and-test:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [18.x, 20.x, 22.x]
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Setup Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v4
+        with:
+          node-version: ${{ matrix.node-version }}
+          cache: "npm"
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Run build
+        run: npm run build
+
+      - name: Run tests
+        run: npm run test

README.md

@@ -131,6 +131,41 @@ Fetches and returns OpenFeature SDK install prompt Markdown for a given technolo
 - react
 - ruby
 
+### `ofrep_flag_eval`
+
+Evaluate feature flags via OpenFeature Remote Evaluation Protocol (OFREP). If `flag_key` is omitted, performs bulk evaluation.
+
+References: [`open-feature/protocol` repo](https://github.com/open-feature/protocol), [OFREP OpenAPI spec](https://raw.githubusercontent.com/open-feature/protocol/refs/heads/main/service/openapi.yaml)
+
+Parameters (all optional unless noted):
+- `base_url` (string, optional): Base URL of your OFREP-compatible flag service. If omitted, the server uses env/config (see below).
+- `flag_key` (string, optional): If provided, calls single flag evaluation: `/ofrep/v1/evaluate/flags/{key}`. If omitted, calls bulk: `/ofrep/v1/evaluate/flags`.
+- `context` (object, optional): Evaluation context, e.g. `{ "targetingKey": "user-123", ... }`.
+- `etag` (string, optional): For bulk requests, sent as `If-None-Match` to enable 304 caching semantics.
+- `auth` (object, optional): Inline auth for this call only.
+  - `bearer_token` (string, optional): Sets `Authorization: Bearer <token>`.
+  - `api_key` (string, optional): Sets `X-API-Key: <key>`.
+
+Auth and base URL resolution (priority):
+1. Tool call args: `base_url`, `auth.bearer_token`, `auth.api_key`
+2. Environment variables: `OPENFEATURE_OFREP_BASE_URL` (or `OFREP_BASE_URL`), `OPENFEATURE_OFREP_BEARER_TOKEN` (or `OFREP_BEARER_TOKEN`), `OPENFEATURE_OFREP_API_KEY` (or `OFREP_API_KEY`)
+3. Config file: `~/.openfeature-mcp.json` (override with `OPENFEATURE_MCP_CONFIG_PATH`)
+
+Example `~/.openfeature-mcp.json`:
+```json
+{
+  "OFREP": {
+    "baseUrl": "https://flags.example.com",
+    "bearerToken": "<token>",
+    "apiKey": "<key>"
+  }
+}
+```
+
+Notes:
+- Bulk requests may return `ETag`. Pass it back via `etag` to leverage 304 Not Modified.
+- Either bearer token or API key can be supplied; both are supported by the spec.
+
 ## Development
 
 ### Prerequisites