Tidewave

Tidewave is the coding agent for full-stack web app development, deeply integrated with Phoenix, from the database to the UI. See our website for more information.

This project can also be used as a standalone Model Context Protocol (MCP) server for your editors.

Installation

Manually

You can install Tidewave by adding the tidewave package to your list of dependencies in mix.exs:

def deps do
  [
    {:tidewave, "~> 0.5", only: :dev}
  ]
end

Then, for Phoenix applications, go to your lib/my_app_web/endpoint.ex and right above the if code_reloading? do block, add:

+  if Code.ensure_loaded?(Tidewave) do
+    plug Tidewave
+  end

   if code_reloading? do

Now access /tidewave route of your web application to enjoy Tidewave Web!

Tidewave Web works best with Phoenix LiveView v1.1 or later. Once you update it, make sure to enable the following options in your config/dev.exs:

config :phoenix_live_view,
  debug_heex_annotations: true,
  debug_attributes: true

Those are enabled by default for Phoenix v1.8+ apps.

If you are running an umbrella project, also add this to your config/runtime.exs:

config :tidewave, :root, File.cwd!()

Using Igniter

Alternatively, you can use igniter to automatically install it into an existing Phoenix application:

# install igniter_new if you haven't already
mix archive.install hex igniter_new

# install tidewave
mix igniter.install tidewave

Now access /tidewave route of your web application to enjoy Tidewave Web!

Usage in non-Phoenix applications

Tidewave can be used as a MCP in any Elixir project. For example, you can use bandit (and tidewave) in dev mode in your mix.exs:

{:tidewave, "~> 0.4", only: :dev},
{:bandit, "~> 1.0", only: :dev},

And then adding an alias in your mix.exs:

aliases: [
  tidewave:
    "run --no-halt -e 'Agent.start(fn -> Bandit.start_link(plug: Tidewave, port: 4000) end)'"
]

Now run mix tidewave and configure Tidewave as a MCP.

Troubleshooting

Tidewave expects your web application to be running on localhost. If you are not running on localhost, you may need to set some additional configuration. In particular, you must pass allow_remote_access: true to plug Tidewave and optionally configure the origin you are accessing from, for example:

  plug Tidewave,
   allow_remote_access: true,
   allowed_origins: ["http://company.local"]

If you want to use Docker for development, you either need to enable the configuration above or automatically redirect the relevant ports, as done by devcontainers. See our containers guide for more information.

Content security policy

If you have enabled Content-Security-Policy, Tidewave will automatically enable "unsafe-eval" under script-src in order for contextual browser testing to work correctly. It also disables the frame-ancestors directive.

Configuration

You may configure the Tidewave plug using the following syntax:

  plug Tidewave, options

The following options are available:

• :allowed_origins - a list of values matched against the Origin header to prevent cross origin and DNS rebinding attacks. Each value must be a string of shape [scheme:]//host[:port], where both scheme and port are optional. The host may also start with "*". Example: ["//localhost:8000", "//*.test"].

• :allow_remote_access - Tidewave only allows requests from localhost by default, even if your server listens on other interfaces as well. If you trust your network and need to access Tidewave from a different machine, this configuration can be set to true.

• :inspect_opts - Custom options passed to Kernel.inspect/2 when formatting some tool results. Defaults to: [charlists: :as_lists, limit: 50, pretty: true]

• :team - set your Tidewave Team configuration, such as team: [id: "my-company"]

Furthermore, the following options are available in the :tidewave application and can configured in your config/runtime.exs:

• :root - The root of your application. It defaults to the current working directory but you may set it to a root directory, in case of monorepos and umbrella projects. For example, you may set it to config :tidewave, :root, File.cwd!() in the config/runtime.exs file of your umbrella root so Tidewave sees your whole project, even when started within a child application. Keep in mind the :root directory must always be version managed by Git

License

Copyright (c) 2025 Dashbit

Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.