diff --git a/README.md b/README.md
index d093b28..dc13ac1 100644
--- a/README.md
+++ b/README.md
@@ -308,6 +308,12 @@ If Mailpit moves, pass the host that Redmine can reach:
 
 The redMCP wrapper now makes Helpdesk behavior explicit:
 
+- `redMCP/bin/redmcp-server.php` runs as a stdio MCP server for live client
+  testing.
+- `issues()` and `filterIssues()` expose Redmine's built-in `/issues.json`
+  issue filters.
+- `search()` and `searchIssues()` expose Redmine's built-in `/search.json`
+  text search.
 - `issueWithHelpdesk()` composes normal issue data with Helpdesk ticket/message
   metadata.
 - `updateIssue()` is safe by default and does not send customer email.
diff --git a/docs/redmineup_local_fork_changelog.md b/docs/redmineup_local_fork_changelog.md
index 6c432d2..4eb1ac4 100644
--- a/docs/redmineup_local_fork_changelog.md
+++ b/docs/redmineup_local_fork_changelog.md
@@ -32,6 +32,33 @@ environment. Before risky edits, archive the current plugin directories in
   - Run `validate_helpdesk_outbox_worker.py` after outbox or worker changes,
     then choose the external index target.
 
+## 2026-04-25 - redMCP Native Search And Filtering
+
+- Touched areas:
+  - `redMCP`
+- Purpose:
+  - Make Redmine's existing issue filtering and built-in text search explicit
+    before adding external search infrastructure.
+  - Make redMCP runnable as a stdio MCP server for live client testing.
+- Behavior changed:
+  - Added `filterIssues()` as a named alias for Redmine's `/issues.json`
+    filtering.
+  - Added `search()` for Redmine's built-in `/search.json` endpoint.
+  - Added `searchIssues()` for issue-only Redmine text search.
+  - Added `redMCP/bin/redmcp-server.php`, a dependency-light stdio MCP server
+    that exposes Redmine filtering/search, issue CRUD, Helpdesk-aware reads, and
+    explicit Helpdesk response tools.
+  - Registered the MCP server as a Composer `bin` entry.
+- LAN test result:
+  - `php -l redMCP/app/RedmineClient.php` passed.
+  - `php -l redMCP/bin/redmcp-server.php` passed.
+  - `composer validate --working-dir=redMCP` passed; Composer emitted PHP 8.5
+    deprecation notices from system Composer dependencies.
+  - Live stdio MCP framing test passed for `initialize`, `tools/list`, and
+    `tools/call` using `redmine_search_issues` against `fud-helpdesk`.
+  - The live MCP tool call returned two issue search results from seven total
+    for `redMCP-smoke`.
+
 ## 2026-04-25 - Test Helpdesk Credential Sanitization
 
 - Touched areas:
diff --git a/redMCP/README.md b/redMCP/README.md
index 678314f..16f44eb 100644
--- a/redMCP/README.md
+++ b/redMCP/README.md
@@ -35,6 +35,7 @@ Basic issue CRUD is exposed on the same wrapper:
 
 ```php
 $issues = $client->issues(['project_id' => 'customer-service', 'status_id' => 'open', 'limit' => 10]);
+$filtered = $client->filterIssues(['query_id' => 12, 'limit' => 25]);
 $issue = $client->issue(39858);
 
 $created = $client->createIssue([
@@ -47,6 +48,23 @@ $client->updateIssue((int) $created['id'], ['notes' => 'Follow-up note']);
 $client->deleteIssue((int) $created['id']);
 ```
 
+Native Redmine search is exposed separately from issue filtering. Use
+`filterIssues()` or `issues()` when you already know the structured filters.
+Use `search()` or `searchIssues()` when you want Redmine's built-in text search:
+
+```php
+$results = $client->search('power supply', [
+    'all_words' => '1',
+    'limit' => 10,
+]);
+
+$issueResults = $client->searchIssues('power supply', [
+    'project_id' => 'customer-service',
+    'open_issues' => '1',
+    'limit' => 10,
+]);
+```
+
 `updateIssue()` is intentionally safe by default: on Helpdesk-backed issues, a
 normal Redmine note does **not** send an email to the customer. To send through
 the Helpdesk plugin, opt in explicitly:
@@ -66,6 +84,33 @@ Use the default non-email update for internal notes, status/category/assignee
 changes, and automation cleanup. Use the Helpdesk email path only when the
 caller deliberately wants the customer to receive mail.
 
+## MCP server
+
+`redMCP` can also run as a stdio MCP server. It reads Redmine credentials from
+environment variables or `redMCP/.env`:
+
+```sh
+redMCP/bin/redmcp-server.php
+```
+
+Example client configuration:
+
+```json
+{
+  "mcpServers": {
+    "redmcp": {
+      "command": "/home/iadnah/redmine/redMCP/bin/redmcp-server.php"
+    }
+  }
+}
+```
+
+The server exposes tools for native Redmine filtering/search, issue CRUD,
+Helpdesk-aware issue reads, and explicit Helpdesk email responses. Tools that
+can send customer-visible mail require an explicit tool call such as
+`redmine_send_helpdesk_response` or `redmine_update_issue` with
+`send_helpdesk_email=true`.
+
 ## Test instance
 
 A working test copy of Redmine is available on the LAN at `192.168.50.170`.
diff --git a/redMCP/app/RedmineClient.php b/redMCP/app/RedmineClient.php
index e5e0b83..21fda60 100644
--- a/redMCP/app/RedmineClient.php
+++ b/redMCP/app/RedmineClient.php
@@ -55,6 +55,56 @@ final class RedmineClient
         return $response;
     }
 
+    /**
+     * Alias for listIssues() that makes Redmine's built-in issue filters
+     * explicit at call sites.
+     *
+     * Useful filters include project_id, tracker_id, status_id,
+     * assigned_to_id, author_id, category_id, fixed_version_id, query_id,
+     * created_on, updated_on, sort, offset, and limit.
+     *
+     * @param array<string,mixed> $filters Standard Redmine issue list filters.
+     *
+     * @return array<string,mixed>
+     */
+    public function filterIssues(array $filters = []): array
+    {
+        return $this->listIssues($filters);
+    }
+
+    /**
+     * Search Redmine using the built-in /search.json endpoint.
+     *
+     * Typical params include project_id, all_words, titles_only, scope,
+     * open_issues, issues, projects, news, documents, changesets, wiki_pages,
+     * messages, offset, and limit.
+     *
+     * @param array<string,mixed> $params Standard Redmine search params.
+     *
+     * @return array<string,mixed>
+     */
+    public function search(string $query, array $params = []): array
+    {
+        $query = trim($query);
+        if ($query === '') {
+            throw new RuntimeException('Searching Redmine requires a non-empty query.');
+        }
+
+        return $this->getJson('/search', ['q' => $query] + $params) ?? [];
+    }
+
+    /**
+     * Search only issues using Redmine's built-in /search.json endpoint.
+     *
+     * @param array<string,mixed> $params Additional Redmine search params.
+     *
+     * @return array<string,mixed>
+     */
+    public function searchIssues(string $query, array $params = []): array
+    {
+        return $this->search($query, ['issues' => '1'] + $params);
+    }
+
     /**
      * Fetch a normal Redmine issue.
      *
diff --git a/redMCP/bin/redmcp-server.php b/redMCP/bin/redmcp-server.php
new file mode 100755
index 0000000..22a89d8
--- /dev/null
+++ b/redMCP/bin/redmcp-server.php
@@ -0,0 +1,361 @@
+#!/usr/bin/env php
+<?php
+
+declare(strict_types=1);
+
+use RedMCP\RedmineClient;
+
+require __DIR__ . '/../vendor/autoload.php';
+
+main();
+
+function main(): void
+{
+    $env = loadEnv(__DIR__ . '/../.env');
+    $url = getenv('REDMINE_URL') ?: ($env['REDMINE_URL'] ?? 'http://192.168.50.170');
+    $apiKey = getenv('REDMINE_API_KEY') ?: getenv('REDMNINE_API_KEY') ?: ($env['REDMINE_API_KEY'] ?? $env['REDMNINE_API_KEY'] ?? null);
+
+    if (!is_string($apiKey) || trim($apiKey) === '') {
+        fwrite(STDERR, "REDMINE_API_KEY is required in the environment or redMCP/.env\n");
+        exit(1);
+    }
+
+    $server = new RedmcpStdioServer(RedmineClient::fromCredentials(rtrim($url, '/'), $apiKey));
+    $server->run();
+}
+
+/**
+ * @return array<string,string>
+ */
+function loadEnv(string $path): array
+{
+    if (!is_file($path)) {
+        return [];
+    }
+
+    $values = [];
+    foreach (file($path, FILE_IGNORE_NEW_LINES) ?: [] as $line) {
+        $line = trim($line);
+        if ($line === '' || str_starts_with($line, '#') || !str_contains($line, '=')) {
+            continue;
+        }
+        [$key, $value] = explode('=', $line, 2);
+        $values[trim($key)] = trim(trim($value), "\"'");
+    }
+
+    return $values;
+}
+
+final class RedmcpStdioServer
+{
+    private RedmineClient $redmine;
+
+    public function __construct(RedmineClient $redmine)
+    {
+        $this->redmine = $redmine;
+    }
+
+    public function run(): void
+    {
+        while (($message = $this->readMessage(STDIN)) !== null) {
+            $this->handleMessage($message);
+        }
+    }
+
+    /**
+     * @param resource $stream
+     *
+     * @return array<string,mixed>|null
+     */
+    private function readMessage($stream): ?array
+    {
+        $headers = [];
+        while (($line = fgets($stream)) !== false) {
+            $line = rtrim($line, "\r\n");
+            if ($line === '') {
+                break;
+            }
+            if (!str_contains($line, ':')) {
+                $decoded = json_decode($line, true);
+                return is_array($decoded) ? $decoded : null;
+            }
+            [$name, $value] = explode(':', $line, 2);
+            $headers[strtolower(trim($name))] = trim($value);
+        }
+
+        if ($line === false && $headers === []) {
+            return null;
+        }
+
+        $length = isset($headers['content-length']) ? (int) $headers['content-length'] : 0;
+        if ($length <= 0) {
+            return null;
+        }
+
+        $body = '';
+        while (strlen($body) < $length && !feof($stream)) {
+            $chunk = fread($stream, $length - strlen($body));
+            if ($chunk === false || $chunk === '') {
+                break;
+            }
+            $body .= $chunk;
+        }
+
+        $decoded = json_decode($body, true);
+        return is_array($decoded) ? $decoded : null;
+    }
+
+    /**
+     * @param array<string,mixed> $message
+     */
+    private function handleMessage(array $message): void
+    {
+        $id = $message['id'] ?? null;
+        $method = (string) ($message['method'] ?? '');
+
+        if ($id === null) {
+            return;
+        }
+
+        try {
+            $result = $this->dispatch($method, is_array($message['params'] ?? null) ? $message['params'] : []);
+            $this->writeMessage(['jsonrpc' => '2.0', 'id' => $id, 'result' => $result]);
+        } catch (Throwable $exception) {
+            $this->writeMessage([
+                'jsonrpc' => '2.0',
+                'id' => $id,
+                'error' => [
+                    'code' => -32000,
+                    'message' => $exception->getMessage(),
+                ],
+            ]);
+        }
+    }
+
+    /**
+     * @param array<string,mixed> $params
+     *
+     * @return array<string,mixed>
+     */
+    private function dispatch(string $method, array $params): array
+    {
+        switch ($method) {
+            case 'initialize':
+                return [
+                    'protocolVersion' => '2024-11-05',
+                    'capabilities' => [
+                        'tools' => ['listChanged' => false],
+                    ],
+                    'serverInfo' => [
+                        'name' => 'redMCP',
+                        'version' => '0.1.0',
+                    ],
+                ];
+            case 'ping':
+                return [];
+            case 'tools/list':
+                return ['tools' => $this->tools()];
+            case 'tools/call':
+                return $this->callTool($params);
+            case 'resources/list':
+                return ['resources' => []];
+            case 'prompts/list':
+                return ['prompts' => []];
+            default:
+                throw new RuntimeException('Unsupported MCP method: ' . $method);
+        }
+    }
+
+    /**
+     * @return array<int,array<string,mixed>>
+     */
+    private function tools(): array
+    {
+        return [
+            $this->tool('redmine_list_issues', 'List Redmine issues using native /issues.json filters.', [
+                'filters' => ['type' => 'object', 'description' => 'Redmine issue list filters such as project_id, status_id, query_id, sort, offset, and limit.'],
+            ]),
+            $this->tool('redmine_search', 'Search Redmine using native /search.json.', [
+                'query' => ['type' => 'string'],
+                'params' => ['type' => 'object', 'description' => 'Redmine search params such as project_id, all_words, titles_only, offset, and limit.'],
+            ], ['query']),
+            $this->tool('redmine_search_issues', 'Search only issues using native /search.json.', [
+                'query' => ['type' => 'string'],
+                'params' => ['type' => 'object', 'description' => 'Additional Redmine search params.'],
+            ], ['query']),
+            $this->tool('redmine_get_issue', 'Fetch one Redmine issue.', [
+                'issue_id' => ['type' => 'integer'],
+                'include' => ['type' => 'array', 'items' => ['type' => 'string'], 'description' => 'Issue includes such as journals, attachments, children, relations, changesets.'],
+            ], ['issue_id']),
+            $this->tool('redmine_issue_with_helpdesk', 'Fetch one issue plus Helpdesk ticket/message context when available.', [
+                'issue_id' => ['type' => 'integer'],
+                'message_limit' => ['type' => 'integer', 'minimum' => 1, 'maximum' => 200],
+                'include' => ['type' => 'array', 'items' => ['type' => 'string']],
+            ], ['issue_id']),
+            $this->tool('redmine_create_issue', 'Create a Redmine issue.', [
+                'fields' => ['type' => 'object', 'description' => 'Issue fields including project_id and subject.'],
+            ], ['fields']),
+            $this->tool('redmine_update_issue', 'Update a Redmine issue. Helpdesk email is opt-in.', [
+                'issue_id' => ['type' => 'integer'],
+                'fields' => ['type' => 'object'],
+                'options' => ['type' => 'object', 'description' => 'Pass send_helpdesk_email=true only for customer-visible Helpdesk replies.'],
+            ], ['issue_id', 'fields']),
+            $this->tool('redmine_delete_issue', 'Delete a Redmine issue.', [
+                'issue_id' => ['type' => 'integer'],
+            ], ['issue_id']),
+            $this->tool('redmine_send_helpdesk_response', 'Send a customer-visible Helpdesk email response.', [
+                'issue_id' => ['type' => 'integer'],
+                'content' => ['type' => 'string'],
+                'options' => ['type' => 'object', 'description' => 'Optional to_address, cc_address, bcc_address, and status_id.'],
+            ], ['issue_id', 'content']),
+        ];
+    }
+
+    /**
+     * @param array<string,mixed> $properties
+     * @param array<int,string> $required
+     *
+     * @return array<string,mixed>
+     */
+    private function tool(string $name, string $description, array $properties, array $required = []): array
+    {
+        return [
+            'name' => $name,
+            'description' => $description,
+            'inputSchema' => [
+                'type' => 'object',
+                'properties' => $properties,
+                'required' => $required,
+                'additionalProperties' => false,
+            ],
+        ];
+    }
+
+    /**
+     * @param array<string,mixed> $params
+     *
+     * @return array<string,mixed>
+     */
+    private function callTool(array $params): array
+    {
+        $name = (string) ($params['name'] ?? '');
+        $arguments = is_array($params['arguments'] ?? null) ? $params['arguments'] : [];
+
+        switch ($name) {
+            case 'redmine_list_issues':
+                $result = $this->redmine->filterIssues($this->objectArg($arguments, 'filters'));
+                break;
+            case 'redmine_search':
+                $result = $this->redmine->search($this->stringArg($arguments, 'query'), $this->objectArg($arguments, 'params'));
+                break;
+            case 'redmine_search_issues':
+                $result = $this->redmine->searchIssues($this->stringArg($arguments, 'query'), $this->objectArg($arguments, 'params'));
+                break;
+            case 'redmine_get_issue':
+                $result = $this->redmine->issue($this->intArg($arguments, 'issue_id'), $this->stringListArg($arguments, 'include', ['journals', 'attachments']));
+                break;
+            case 'redmine_issue_with_helpdesk':
+                $result = $this->redmine->issueWithHelpdesk(
+                    $this->intArg($arguments, 'issue_id'),
+                    $this->intArg($arguments, 'message_limit', 100),
+                    $this->stringListArg($arguments, 'include', ['journals', 'attachments'])
+                );
+                break;
+            case 'redmine_create_issue':
+                $result = $this->redmine->createIssue($this->objectArg($arguments, 'fields'));
+                break;
+            case 'redmine_update_issue':
+                $result = ['ok' => $this->redmine->updateIssue($this->intArg($arguments, 'issue_id'), $this->objectArg($arguments, 'fields'), $this->objectArg($arguments, 'options'))];
+                break;
+            case 'redmine_delete_issue':
+                $result = ['ok' => $this->redmine->deleteIssue($this->intArg($arguments, 'issue_id'))];
+                break;
+            case 'redmine_send_helpdesk_response':
+                $result = $this->redmine->sendHelpdeskIssueResponse($this->intArg($arguments, 'issue_id'), $this->stringArg($arguments, 'content'), $this->objectArg($arguments, 'options'));
+                break;
+            default:
+                throw new RuntimeException('Unknown tool: ' . $name);
+        }
+
+        $encoded = json_encode($result, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);
+        if ($encoded === false) {
+            throw new RuntimeException('Could not encode tool result.');
+        }
+
+        return [
+            'content' => [
+                [
+                    'type' => 'text',
+                    'text' => $encoded,
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * @param array<string,mixed> $arguments
+     *
+     * @return array<string,mixed>
+     */
+    private function objectArg(array $arguments, string $key): array
+    {
+        return is_array($arguments[$key] ?? null) ? $arguments[$key] : [];
+    }
+
+    /**
+     * @param array<string,mixed> $arguments
+     */
+    private function stringArg(array $arguments, string $key): string
+    {
+        $value = trim((string) ($arguments[$key] ?? ''));
+        if ($value === '') {
+            throw new RuntimeException($key . ' is required.');
+        }
+
+        return $value;
+    }
+
+    /**
+     * @param array<string,mixed> $arguments
+     */
+    private function intArg(array $arguments, string $key, ?int $default = null): int
+    {
+        if (!isset($arguments[$key])) {
+            if ($default !== null) {
+                return $default;
+            }
+            throw new RuntimeException($key . ' is required.');
+        }
+
+        return (int) $arguments[$key];
+    }
+
+    /**
+     * @param array<string,mixed> $arguments
+     * @param array<int,string> $default
+     *
+     * @return array<int,string>
+     */
+    private function stringListArg(array $arguments, string $key, array $default): array
+    {
+        if (!isset($arguments[$key]) || !is_array($arguments[$key])) {
+            return $default;
+        }
+
+        return array_values(array_filter(array_map('strval', $arguments[$key])));
+    }
+
+    /**
+     * @param array<string,mixed> $message
+     */
+    private function writeMessage(array $message): void
+    {
+        $body = json_encode($message, JSON_UNESCAPED_SLASHES);
+        if ($body === false) {
+            return;
+        }
+
+        fwrite(STDOUT, 'Content-Length: ' . strlen($body) . "\r\n\r\n" . $body);
+        fflush(STDOUT);
+    }
+}
diff --git a/redMCP/composer.json b/redMCP/composer.json
index 401223e..cd70c53 100644
--- a/redMCP/composer.json
+++ b/redMCP/composer.json
@@ -7,6 +7,9 @@
             "RedMCP\\": "app/"
         }
     },
+    "bin": [
+        "bin/redmcp-server.php"
+    ],
     "require": {
         "kbsali/redmine-api": "^2.9"
     }