This is a web application written using the Phoenix web framework.
Vocabulary
Read docs/taxonomy.md before writing docs, commit messages, or product copy.
It defines what each word means here — forge versus GitHub, push versus
deploy, computer versus machine, which receipt, which module — and the naming
rules that keep them straight.
Communication style
All text in this repo — docs, README, AGENTS.md, commit messages, and agent responses — follows the Google Developer Documentation Style Guide. When writing or reviewing text, read the google-developer-style skill at .agents/skills/google-developer-style/SKILL.md.
- Write in active voice and address the reader as
you. - Use sentence case for all headings and titles.
- Use code font for code, filenames, class names, HTTP status codes, and placeholders.
- Use bold for UI elements.
- Use numbered lists for procedures and bulleted lists for unrelated items.
- Avoid jargon, buzzwords, metaphors, exclamation marks, and phrases like
simplyorjust. - Avoid
pleasein instructions.
Git remotes
Push to the forge, never to GitHub:
git push openagents HEAD:main
The openagents remote is the forge at openagents.com, which records every
push in the durable WAL and serves it. The origin remote is the GitHub
mirror; pushing to it directly leaves the forge behind a mirror it does not
know about, and nothing reports the divergence until a clone disagrees with
the site. Production mirrors to GitHub with a force push of every ref, so a
direct GitHub push is not merged later — it is overwritten. GitHub
holds what the forge last mirrored there. ops/ci/push-remote-check.sh refuses
a non-forge push, and mix precommit installs it into the clone you are
working in, so running precommit before you push is enough. To install it by
hand:
sh ops/dev/install-push-guard.sh
One install covers every worktree of that clone. Where core.hooksPath points
at .githooks, its pre-push runs the same guard ahead of the release gate.
See INVARIANTS.md, REPOSITORY-002.
Project guidelines
- Use
mix precommitalias when you are done with all changes and fix any pending issues - Use the already included and available
:req(Req) library for HTTP requests, avoid:httpoison,:tesla, and:httpc. Req is included by default and is the preferred HTTP client for Phoenix apps
Phoenix v1.8 guidelines
- Always begin your LiveView templates with
<Layouts.app flash={@flash} ...>which wraps all inner content - The
MyAppWeb.Layoutsmodule is aliased in themy_app_web.exfile, so you can use it without needing to alias it again - Anytime you run into errors with no
current_scopeassign:- You failed to follow the Authenticated Routes guidelines, or you failed to pass
current_scopeto<Layouts.app> - Always fix the
current_scopeerror by moving your routes to the properlive_sessionand ensure you passcurrent_scopeas needed
- You failed to follow the Authenticated Routes guidelines, or you failed to pass
- Phoenix v1.8 moved the
<.flash_group>component to theLayoutsmodule. You are forbidden from calling<.flash_group>outside of thelayouts.exmodule - Render icons only through
OpenAgentsWeb.UI.icon/1. Prefer the vendored Apps SDK set. Use ahero-*fallback only whendocs/ICONS.mdrecords why the preferred set has no suitable glyph - Always use the imported
OpenAgentsWeb.UI.input/1component for form inputs. It acceptsPhoenix.HTML.FormFieldvalues and unwrapped raw controls - If you override the default input classes (
<.input class="myclass px-2 py-1 rounded-lg">)) class with your own values, no default classes are inherited, so your custom classes must fully style the input
JS and CSS guidelines
-
Use Tailwind CSS classes and custom CSS rules to create polished, responsive, and visually stunning interfaces.
-
Tailwindcss v4 no longer needs a tailwind.config.js and uses a new import syntax in
app.css:@import "tailwindcss" source(none); @source "../css"; @source "../js"; @source "../../lib/my_app_web"; -
Always use and maintain this import syntax in the app.css file for projects generated with
phx.new -
Never use
@applywhen writing raw css -
There is exactly one component system: vendored Basecoat plus OpenAgents style pack. Basecoat lives in
assets/vendor/basecoat/components/and carries structure (display, padding, min-height);assets/css/openagents.csscarries OpenAgents' identity (motion tokens, radius scale, color, the notched variant, corner frames) and must stay the last import so its declarations win.- Reach for
OpenAgentsWeb.UIfirst. It wraps that CSS in 22 ready primitives —button/1,card/1,badge/1,alert/1,input/1,textarea/1,label/1,field/1,header/1,table/1,list/1,avatar/1,menu/1,empty/1,kbd/1, and the rest. Fall back to hand-written classes only when no primitive covers the shape. - Variants are data attributes, not classes. A control is
class="btn"plusdata-variant="primary"/data-size="sm"/data-tone="danger". Never inventbtn-primary-style variant classes; they defeat the whole point of the split. - Never add a second component library — DaisyUI above all. DaisyUI was removed deliberately. It emitted flat
.btnrules (setting background, color, border) from a cascade layer that outranked every.btn[data-variant=…]inopenagents.css, so all eight UI button variants rendered identically on staging. Any library with the same shape will do the same thing again. - Import Basecoat components individually, one
@import "../vendor/basecoat/components/<name>.css"per component a surface actually uses. Component CSS lands in@layer componentsand ships whether or not the class appears in markup, so the list is a budget. Never importbasecoat.css,basecoat-base.css, orbasecoat-components.css— each pulls in all 39 components at once. - The palette is the two owned token ladders in
assets/css/openagents.css. The interface supports only light and dark palettes; the system preference selects between them and is not a third palette. Use the Basecoat utility names built on these tokens —bg-background,bg-card,text-foreground,text-muted-foreground, andborder-border. The retired compatibility aliases no longer exist
- Reach for
-
Add custom Tailwind only when the design is unique to OpenAgents and no primitive fits.
-
Out of the box only the app.js and app.css bundles are supported
- You cannot reference an external vendor'd script
srcor linkhrefin the layouts - You must import the vendor deps into app.js and app.css to use them
- Never write inline
<script>tags within templates. The only exception is the synchronous, content-free theme bootstrap inroot.html.heex, which must run before the first stylesheet paint and carry the response-scoped CSP nonce. Put every other client behavior inapp.jsor a colocated LiveView hook
- You cannot reference an external vendor'd script
UI and UX design guidelines
- Produce world-class UI designs with a focus on usability, aesthetics, and modern design principles
- Implement subtle micro-interactions (e.g., button hover effects, and smooth transitions)
- Ensure clean typography, spacing, and layout balance for a refined, premium look
- Focus on delightful details like hover effects, loading states, and smooth page transitions
Elixir guidelines
-
Elixir lists do not support index based access via the access syntax
Never do this (invalid):
i = 0 mylist = ["blue", "green"] mylist[i]Instead, always use
Enum.at, pattern matching, orListfor index based list access, ie:i = 0 mylist = ["blue", "green"] Enum.at(mylist, i) -
Elixir variables are immutable, but can be rebound, so for block expressions like
if,case,cond, etc you must bind the result of the expression to a variable if you want to use it and you CANNOT rebind the result inside the expression, ie:# INVALID: we are rebinding inside the `if` and the result never gets assigned if connected?(socket) do socket = assign(socket, :val, val) end # VALID: we rebind the result of the `if` to a new variable socket = if connected?(socket) do assign(socket, :val, val) end -
Never nest multiple modules in the same file as it can cause cyclic dependencies and compilation errors
-
Never use map access syntax (
changeset[:field]) on structs as they do not implement the Access behaviour by default. For regular structs, you must access the fields directly, such asmy_struct.fieldor use higher level APIs that are available on the struct if they exist,Ecto.Changeset.get_field/2for changesets -
Elixir's standard library has everything necessary for date and time manipulation. Familiarize yourself with the common
Time,Date,DateTime, andCalendarinterfaces by accessing their documentation as necessary. Never install additional dependencies unless asked or for date/time parsing (which you can use thedate_time_parserpackage) -
Don't use
String.to_atom/1on user input (memory leak risk) -
Predicate function names should not start with
is_and should end in a question mark. Names likeis_thingshould be reserved for guards -
Elixir's builtin OTP primitives like
DynamicSupervisorandRegistry, require names in the child spec, such as{DynamicSupervisor, name: MyApp.MyDynamicSup}, then you can useDynamicSupervisor.start_child(MyApp.MyDynamicSup, child_spec) -
Use
Task.async_stream(collection, callback, options)for concurrent enumeration with back-pressure. The majority of times you will want to passtimeout: :infinityas option
Mix guidelines
- Read the docs and options before using tasks (by using
mix help task_name) - To debug test failures, run tests in a specific file with
mix test test/my_test.exsor run all previously failed tests withmix test --failed mix deps.clean --allis almost never needed. Avoid using it unless you have good reason
Test guidelines
- Always use
start_supervised!/1to start processes in tests as it guarantees cleanup between tests - Avoid
Process.sleep/1andProcess.alive?/1in tests-
Instead of sleeping to wait for a process to finish, always use
Process.monitor/1and assert on the DOWN message:ref = Process.monitor(pid) assert_receive {:DOWN, ^ref, :process, ^pid, :normal}
-
Instead of sleeping to synchronize before the next call, always use
_ = :sys.get_state/1to ensure the process has handled prior messages
-
Phoenix guidelines
-
Remember Phoenix router
scopeblocks include an optional alias which is prefixed for all routes within the scope. Always be mindful of this when creating routes within a scope to avoid duplicate module prefixes. -
You never need to create your own
aliasfor route definitions! Thescopeprovides the alias, ie:scope "/admin", AppWeb.Admin do pipe_through :browser live "/users", UserLive, :index endthe UserLive route would point to the
AppWeb.Admin.UserLivemodule -
Phoenix.Viewno longer is needed or included with Phoenix, don't use it
Ecto Guidelines
- Always preload Ecto associations in queries when they'll be accessed in templates, ie a message that needs to reference the
message.user.email - Remember
import Ecto.Queryand other supporting modules when you writeseeds.exs Ecto.Schemafields always use the:stringtype, even for:text, columns, ie:field :name, :stringEcto.Changeset.validate_number/2DOES NOT SUPPORT the:allow_niloption. By default, Ecto validations only run if a change for the given field exists and the change value is not nil, so such as option is never needed- You must use
Ecto.Changeset.get_field(changeset, :field)to access changeset fields - Fields which are set programmatically, such as
user_id, must not be listed incastcalls or similar for security purposes. Instead they must be explicitly set when creating the struct - Always invoke
mix ecto.gen.migration migration_name_using_underscoreswhen generating migration files, so the correct timestamp and conventions are applied
Phoenix HTML guidelines
-
Phoenix templates always use
~Hor .html.heex files (known as HEEx), never use~E -
Always use the imported
Phoenix.Component.form/1andPhoenix.Component.inputs_for/1function to build forms. Never usePhoenix.HTML.form_fororPhoenix.HTML.inputs_foras they are outdated -
When building forms always use the already imported
Phoenix.Component.to_form/2(assign(socket, form: to_form(...))and<.form for={@form} id="msg-form">), then access those forms in the template via@form[:field] -
Always add unique DOM IDs to key elements (like forms, buttons, etc) when writing templates, these IDs can later be used in tests (
<.form for={@form} id="product-form">) -
For "app wide" template imports, you can import/alias into the
my_app_web.ex'shtml_helpersblock, so they will be available to all LiveViews, LiveComponent's, and all modules that douse MyAppWeb, :html(replace "my_app" by the actual app name) -
Elixir supports
if/elsebut does NOT supportif/else iforif/elsif. Never useelse iforelseifin Elixir, always usecondorcasefor multiple conditionals.Never do this (invalid):
<%= if condition do %> ... <% else if other_condition %> ... <% end %>Instead always do this:
<%= cond do %> <% condition -> %> ... <% condition2 -> %> ... <% true -> %> ... <% end %> -
HEEx require special tag annotation if you want to insert literal curly's like
{or}. If you want to show a textual code snippet on the page in a<pre>or<code>block you must annotate the parent tag withphx-no-curly-interpolation:<code phx-no-curly-interpolation> let obj = {key: "val"} </code>Within
phx-no-curly-interpolationannotated tags, you can use{and}without escaping them, and dynamic Elixir expressions can still be used with<%= ... %>syntax -
HEEx class attrs support lists, but you must always use list
[...]syntax. You can use the class list syntax to conditionally add classes, always do this for multiple class values:<a class={[ "px-2 text-white", @some_flag && "py-5", if(@other_condition, do: "border-red-500", else: "border-blue-100"), ... ]}>Text</a>and always wrap
if's inside{...}expressions with parens, like done above (if(@other_condition, do: "...", else: "..."))and never do this, since it's invalid (note the missing
[and]):<a class={ "px-2 text-white", @some_flag && "py-5" }> ... => Raises compile syntax error on invalid HEEx attr syntax -
Never use
<% Enum.each %>or non-for comprehensions for generating template content, instead always use<%= for item <- @collection do %> -
HEEx HTML comments use
<%!-- comment --%>. Always use the HEEx HTML comment syntax for template comments (<%!-- comment --%>) -
HEEx allows interpolation via
{...}and<%= ... %>, but the<%= %>only works within tag bodies. Always use the{...}syntax for interpolation within tag attributes, and for interpolation of values within tag bodies. Always interpolate block constructs (if, cond, case, for) within tag bodies using<%= ... %>.Always do this:
<div id={@id}> {@my_assign} <%= if @some_block_condition do %> {@another_assign} <% end %> </div>and Never do this – the program will terminate with a syntax error:
<%!-- THIS IS INVALID NEVER EVER DO THIS --%> <div id="<%= @invalid_interpolation %>"> {if @invalid_block_construct do} {end} </div>
Phoenix LiveView guidelines
- Never use the deprecated
live_redirectandlive_patchfunctions, instead always use the<.link navigate={href}>and<.link patch={href}>in templates, andpush_navigateandpush_patchfunctions LiveViews - Avoid LiveComponent's unless you have a strong, specific need for them
- LiveViews should be named like
AppWeb.WeatherLive, with aLivesuffix. When you go to add LiveView routes to the router, the default:browserscope is already aliased with theAppWebmodule, so you can just dolive "/weather", WeatherLive
LiveView streams
-
Always use LiveView streams for collections for assigning regular lists to avoid memory ballooning and runtime termination with the following operations:
- basic append of N items -
stream(socket, :messages, [new_msg]) - resetting stream with new items -
stream(socket, :messages, [new_msg], reset: true)(e.g. for filtering items) - prepend to stream -
stream(socket, :messages, [new_msg], at: -1) - deleting items -
stream_delete(socket, :messages, msg)
- basic append of N items -
-
When using the
stream/3interfaces in the LiveView, the LiveView template must 1) always setphx-update="stream"on the parent element, with a DOM id on the parent element likeid="messages"and 2) consume the@streams.stream_namecollection and use the id as the DOM id for each child. For a call likestream(socket, :messages, [new_msg])in the LiveView, the template would be:<div id="messages" phx-update="stream"> <div :for={{id, msg} <- @streams.messages} id={id}> {msg.text} </div> </div> -
LiveView streams are not enumerable, so you cannot use
Enum.filter/2orEnum.reject/2on them. Instead, if you want to filter, prune, or refresh a list of items on the UI, you must refetch the data and re-stream the entire stream collection, passing reset: true:def handle_event("filter", %{"filter" => filter}, socket) do # re-fetch the messages based on the filter messages = list_messages(filter) {:noreply, socket |> assign(:messages_empty?, messages == []) # reset the stream with the new messages |> stream(:messages, messages, reset: true)} end -
LiveView streams do not support counting or empty states. If you need to display a count, you must track it using a separate assign. For empty states, you can use Tailwind classes:
<div id="tasks" phx-update="stream"> <div class="hidden only:block">No tasks yet</div> <div :for={{id, task} <- @streams.tasks} id={id}> {task.name} </div> </div>The above only works if the empty state is the only HTML block alongside the stream for-comprehension.
-
When updating an assign that should change content inside any streamed item(s), you MUST re-stream the items along with the updated assign:
def handle_event("edit_message", %{"message_id" => message_id}, socket) do message = Chat.get_message!(message_id) edit_form = to_form(Chat.change_message(message, %{content: message.content})) # re-insert message so @editing_message_id toggle logic takes effect for that stream item {:noreply, socket |> stream_insert(:messages, message) |> assign(:editing_message_id, String.to_integer(message_id)) |> assign(:edit_form, edit_form)} endAnd in the template:
<div id="messages" phx-update="stream"> <div :for={{id, message} <- @streams.messages} id={id} class="flex group"> {message.username} <%= if @editing_message_id == message.id do %> <%!-- Edit mode --%> <.form for={@edit_form} id="edit-form-#{message.id}" phx-submit="save_edit"> ... </.form> <% end %> </div> </div> -
Never use the deprecated
phx-update="append"orphx-update="prepend"for collections
LiveView JavaScript interop
- Remember anytime you use
phx-hook="MyHook"and that JS hook manages its own DOM, you must also set thephx-update="ignore"attribute - Always provide an unique DOM id alongside
phx-hookotherwise a compiler error will be raised
LiveView hooks come in two flavors, 1) colocated js hooks for "inline" scripts defined inside HEEx,
and 2) external phx-hook annotations where JavaScript object literals are defined and passed to the LiveSocket constructor.
Inline colocated js hooks
Never write raw embedded <script> tags in heex as they are incompatible with LiveView.
Instead, always use a colocated js hook script tag (:type={Phoenix.LiveView.ColocatedHook})
when writing scripts inside the template:
<input type="text" name="user[phone_number]" id="user-phone-number" phx-hook=".PhoneNumber" />
<script :type={Phoenix.LiveView.ColocatedHook} name=".PhoneNumber">
export default {
mounted() {
this.el.addEventListener("input", e => {
let match = this.el.value.replace(/\D/g, "").match(/^(\d{3})(\d{3})(\d{4})$/)
if(match) {
this.el.value = `${match[1]}-${match[2]}-${match[3]}`
}
})
}
}
</script>
- colocated hooks are automatically integrated into the app.js bundle
- colocated hooks names MUST ALWAYS start with a
.prefix, i.e..PhoneNumber
External phx-hook
External JS hooks (<div id="myhook" phx-hook="MyHook">) must be placed in assets/js/ and passed to the
LiveSocket constructor:
const MyHook = {
mounted() { ... }
}
let liveSocket = new LiveSocket("/live", Socket, {
hooks: { MyHook }
});
Pushing events between client and server
Use LiveView's push_event/3 when you need to push events/data to the client for a phx-hook to handle.
Always return or rebind the socket on push_event/3 when pushing events:
# re-bind socket so we maintain event state to be pushed
socket = push_event(socket, "my_event", %{...})
# or return the modified socket directly:
def handle_event("some_event", _, socket) do
{:noreply, push_event(socket, "my_event", %{...})}
end
Pushed events can then be picked up in a JS hook with this.handleEvent:
mounted() {
this.handleEvent("my_event", data => console.log("from server:", data));
}
Clients can also push an event to the server and receive a reply with this.pushEvent:
mounted() {
this.el.addEventListener("click", e => {
this.pushEvent("my_event", { one: 1 }, reply => console.log("got reply from server:", reply));
})
}
Where the server handled it via:
def handle_event("my_event", %{"one" => 1}, socket) do
{:reply, %{two: 2}, socket}
end
LiveView tests
-
Phoenix.LiveViewTestmodule andLazyHTML(included) for making your assertions -
Form tests are driven by
Phoenix.LiveViewTest'srender_submit/2andrender_change/2functions -
Come up with a step-by-step test plan that splits major test cases into small, isolated files. You may start with simpler tests that verify content exists, gradually add interaction tests
-
Always reference the key element IDs you added in the LiveView templates in your tests for
Phoenix.LiveViewTestfunctions likeelement/2,has_element/2, selectors, etc -
Never tests again raw HTML, always use
element/2,has_element/2, and similar:assert has_element?(view, "#my-form") -
Instead of relying on testing text content, which can change, favor testing for the presence of key elements
-
Focus on testing outcomes rather than implementation details
-
Be aware that
Phoenix.Componentfunctions like<.form>might produce different HTML than expected. Test against the output HTML structure, not your mental model of what you expect it to be -
When facing test failures with element selectors, add debug statements to print the actual HTML, but use
LazyHTMLselectors to limit the output, ie:html = render(view) document = LazyHTML.from_fragment(html) matches = LazyHTML.filter(document, "your-complex-selector") IO.inspect(matches, label: "Matches")
Form handling
Creating a form from params
If you want to create a form based on handle_event params:
def handle_event("submitted", params, socket) do
{:noreply, assign(socket, form: to_form(params))}
end
When you pass a map to to_form/1, it assumes said map contains the form params, which are expected to have string keys.
You can also specify a name to nest the params:
def handle_event("submitted", %{"user" => user_params}, socket) do
{:noreply, assign(socket, form: to_form(user_params, as: :user))}
end
Creating a form from changesets
When using changesets, the underlying data, form params, and errors are retrieved from it. The :as option is automatically computed too. E.g. if you have a user schema:
defmodule MyApp.Users.User do
use Ecto.Schema
...
end
And then you create a changeset that you pass to to_form:
%MyApp.Users.User{}
|> Ecto.Changeset.change()
|> to_form()
Once the form is submitted, the params will be available under %{"user" => user_params}.
In the template, the form form assign can be passed to the <.form> function component:
<.form for={@form} id="todo-form" phx-change="validate" phx-submit="save">
<.input field={@form[:field]} type="text" />
</.form>
Always give the form an explicit, unique DOM ID, like id="todo-form".
Avoiding form errors
Always use a form assigned via to_form/2 in the LiveView, and the <.input> component in the template. In the template always access forms this:
<%!-- ALWAYS do this (valid) --%>
<.form for={@form} id="my-form">
<.input field={@form[:field]} type="text" />
</.form>
And never do this:
<%!-- NEVER do this (invalid) --%>
<.form for={@changeset} id="my-form">
<.input field={@changeset[:field]} type="text" />
</.form>
- You are FORBIDDEN from accessing the changeset in the template as it will cause errors
- Never use
<.form let={f} ...>in the template, instead always use<.form for={@form} ...>, then drive all form references from the form assign as in@form[:field]. The UI should always be driven by ato_form/2assigned in the LiveView module that is derived from a changeset
Test-driven development workflow
We are driving the GitHub-compatible Issues and Projects API through tests. This section applies while we build that surface.
Principles
- One endpoint at a time. Each new endpoint starts with a failing test before the route, controller, context, or schema exists.
- Tests are the contract. The GitHub REST API description in
docs/github-api-issues-projects-assessment.mdis the source of truth for paths, status codes, and JSON shape. - Use
OpenAgentsWeb.ConnCasefor controller and JSON API tests, andOpenAgents.DataCasefor domain tests. - Use
Reqfor outbound fixtures we mirror. Prefer captured GitHub API responses stored intest/fixtures/github/*.json. - Focus each test on one thing: status, a few key fields, and the link between the request and the database.
- Avoid
Process.sleep/1in tests. Use monitors andassert_receivewhen waiting for process teardown.
Order of work
Build the endpoints in this order:
GET /api/v1/repos/{owner}/{repo}/issues— listGET /api/v1/repos/{owner}/{repo}/issues/{issue_number}— getPOST /api/v1/repos/{owner}/{repo}/issues— createPATCH /api/v1/repos/{owner}/{repo}/issues/{issue_number}— updateGET/POST /api/v1/repos/{owner}/{repo}/issues/{issue_number}/comments— commentsGET/POST/DELETE /api/v1/repos/{owner}/{repo}/issues/{issue_number}/assignees— assigneesGET/POST/DELETE /api/v1/repos/{owner}/{repo}/issues/{issue_number}/labels— labelsGET/POST/DELETE /api/v1/repos/{owner}/{repo}/milestones— milestones/api/v1/users/{username}/projectsV2/*— project read and write
Test anatomy
Each endpoint test file follows this shape:
defmodule OpenAgentsWeb.IssueControllerTest do
use OpenAgentsWeb.ConnCase
test "GET /api/v1/repos/:owner/:repo/issues lists open issues", %{conn: conn} do
conn = get(conn, ~p"/api/v1/repos/OpenAgentsInc/openagents.com/issues")
assert json_response(conn, 200)["issues"] != nil
end
end
Running tests
- Run one file:
mix test test/openagents_web/controllers/issue_controller_test.exs - Run a failed set:
mix test --failed - Before a final commit: run
mix precommitand fix all compile warnings, formatting, and test failures.