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 server.

Installation

Manually

Add the tidewave package to your mix.exs:

def deps do
  [
    {:tidewave, "~> 0.5", only: :dev},
    {:phoenix, ...},
  ]
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 Mix.env() == :dev do
+    plug Tidewave
+  end

   if code_reloading? do

Now make sure Tidewave is installed and you are ready to connect Tidewave to your app.

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.

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 make sure Tidewave is installed and you are ready to connect Tidewave to your app.

Umbrella projects

For umbrella projects, you can follow the manual steps above in the application that defines your Phoenix endpoint (typically apps/your_app_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

Using multiple hosts/subdomains

If you are using multiple hosts/subdomains during development, you must use *.localhost, as such domains are considered secure by browsers. Additionally, add the following immediately @session_options definition in your lib/your_app_web/endpoint.ex:

@session_options [
  # ... your configuration
]

if code_reloading? do
  @session_options Keyword.merge(@session_options, same_site: "None", secure: true)
end

The above will allow your application to run embedded within Tidewave across multiple subdomains, as long as it is using a secure context (such as admin.localhost, www.foobar.localhost, etc).

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:

• :allow_remote_access - Tidewave only allows requests from localhost by default, even if your server listens on other interfaces, for security purposes. Read our security guidelines for more information and when to allow remote access (if you know what you are doing)

• :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"]

Available tools

• execute_sql_query - executes a SQL query within your application database, useful for the agent to verify the result of an action

• get_docs - get the documentation for a given module/function. It consults the exact versions used by the project, ensuring you always get correct information

• get_logs - reads logs written by the server

• get_models - lists all modules in the application and their location for quick discovery

• get_source_location - get the source location for a given module/function, so an agent can directly read the source skipping search

• project_eval - evaluates code within the your application itself, giving the agent access to your runtime, dependencies, and in-memory data

• search_package_docs - runs a search on https://hexdocs.pm/ filtered to the exact dependencies in this project

get_ecto_schemas and get_ash_resources is also available if you are using Ecto and Ash respectively.

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.