Hello,
I’m struggling to figure out why my api is sending me a 400 error on create route. Show and index route are working fine.
I tried different playload, I double check there was no error in json playload and

Here is my controller (auto generated with phoenix generator):

defmodule ColdDataApiWeb.ProjectController do
  use ColdDataApiWeb, :controller

  alias ColdDataApi.Record
  alias ColdDataApi.Record.Project

  action_fallback ColdDataApiWeb.FallbackController

  def index(conn, _params) do
    projects = Record.list_projects()
    render(conn, "index.json", projects: projects)
  end

  def create(conn, %{"project" => project_params}) do
    with {:ok, %Project{} = project} <- Record.create_project(project_params) do
      conn
      |> put_status(:created)
      |> put_resp_header("location", project_path(conn, :show, project))
      |> render("show.json", project: project)
    end
  end

  def show(conn, %{"id" => id}) do
    project = Record.get_project!(id)
    render(conn, "show.json", project: project)
  end

  def update(conn, %{"id" => id, "project" => project_params}) do
    project = Record.get_project!(id)

    with {:ok, %Project{} = project} <- Record.update_project(project, project_params) do
      render(conn, "show.json", project: project)
    end
  end

  def delete(conn, %{"id" => id}) do
    project = Record.get_project!(id)
    with {:ok, %Project{}} <- Record.delete_project(project) do
      send_resp(conn, :no_content, "")
    end
  end
end

My schema:

defmodule ColdDataApi.Record.Project do
  use Ecto.Schema
  import Ecto.Changeset

  schema "projects" do
    field :name, :string
    field :short_description, :string
    field :description, :string
    field :human_name, :string

  end

  @allowed_fields [:name, :short_description, :description, :human_name]
  @required_fields [:name, :short_description, :human_name]

  @doc false
  def changeset(project, attrs) do
    project
    |> cast(attrs, @allowed_fields)
    |> validate_required(@required_fields)
    |> validate_length(:name, max: 40, count: :codepoints)
    |> validate_length(:short_description, max: 600, count: :codepoints)
    |> validate_length(:human_name, max: 40, count: :codepoints)
    |> validate_length(:description, max: 65_535, count: :codepoints)
    |> unique_constraint(:name)
  end
end

My FallbackController:

defmodule ColdDataApiWeb.FallbackController do
  @moduledoc """
  Translates controller action results into valid `Plug.Conn` responses.

  See `Phoenix.Controller.action_fallback/1` for more details.
  """
  use ColdDataApiWeb, :controller

  def call(conn, {:error, %Ecto.Changeset{} = changeset}) do
    conn
    |> put_status(:unprocessable_entity)
    |> render(ColdDataApiWeb.ChangesetView, "error.json", changeset: changeset)
  end

  def call(conn, {:error, :not_found}) do
    conn
    |> put_status(:not_found)
    |> render(ColdDataApiWeb.ErrorView, :"404")
  end
end

I add the routes like this:

  # Other scopes may use custom stacks.
  scope "/api/v1", ColdDataApiWeb do
    pipe_through :api

    resources "/projects", ProjectController, except: [:new, :edit]
  end

I tested in iex console, Record.create_project works. I suppose the error come from the controller.
Does anyone could give me an hint on this error ?

Ps: english is not my mother tongue, so do not hesitate to ask me question if something is unclear.