CHANGELOG.md

0.4.5 (2026-04-29)

• Fix Plug.Conn.AlreadySentError when a second SSE GET arrives for an existing session. The conflict response (409 -32000) is now returned cleanly without attempting to write streaming headers on the sent conn.

0.4.4 (2026-04-13)

• Defend from potential elicitation replication lag
• Track Elicitations to ensure duplicate requests are not sent

0.4.3 (2026-04-03)

• Fix invalid response when client request an invalid resource_uri

0.4.2 (2026-04-03)

• Elicitation requests can use the POSTs connection. This should fix hung-up elicitations.
• Phoenix.Tracker can take some time to replicate, so add retries when session metadata is not available
• Improve cross-nodes tests

0.4.1 (2026-04-02)

• Add additional Logging when dispatching requests to unalive PIDs
• Catch exits due to calling unalive PIDs (thanks @davydog187)
• Fix Phantom.Tracker
• Fixup dialyzer specs
• Providing nil to binary response content (eg, image, audio) will now raise instead of encoding <<>>.

0.4.0 (2026-03-27)

• Add Phantom.Stdio adapter for local-only clients (e.g. Claude Desktop). Add {Phantom.Stdio, router: MyApp.MCP.Router} to your supervision tree. See Phantom.Stdio for more details.

• Add Phantom.Icon support for server info, tools, and prompts per MCP 2025-11-25 specification. Icons can be set at the router level with use Phantom.Router, icons: [...] or per-tool/prompt.

• Server now declares support for MCP spec 2025-11-25.

• Elicitation support is fully implemented. Phantom.Session.elicit/3 now blocks until the client responds (with configurable timeout) and works across both HTTP and stdio transports. See Phantom.Elicit.

• Phantom.Tracker now works without phoenix_pubsub for stdio transport, falling back to process dictionary for session metadata.

• Fixed bugs with rendering embedded_resources

• New tool DSL with do block to provide input schemas using an Ecto.Schema-like syntax. For example, before you had to manually write the JSONSchema input schema:

  tool :validated_echo_tool,
    description: "Echo with validation",
    input_schema: %{
      required: ~w[message],
      properties: %{
        message: %{type: "string", description: "Foo bar"},
        count: %{type: "integer", description: "Foo bar"},
        tags: %{type: "array", items: %{type: :string}, description: "Foo bar"}
      }
    }

  But now you can declare it with a do block:

  tool :validated_echo_tool, description: "Echo with validation" do
    field :message, :string, required: true, description: "Foo bar"
    field :count, :integer, default: 1, description: "Foo bar"
    field :tags, {:array, :string}, description: "Foo bar"
  end

  The do block also supports nested maps, custom validators, and all JSON Schema types. The old map-based input_schema syntax continues to work. See Phantom.Tool.JSONSchema for more info.

0.3.4 (2026-02-24)

• Breaking When using Phantom.Plug, pass the conn to the router connect callback instead of a map with params and headers keys. Upgrade and make this adjustment in your connect callback:

  # Before
  def connect(session, context) do
    %{params: params, headers: headers} = context
    # ...
  end
  
  # After
  def connect(session, conn) do
    %{query_params: params, req_headers: headers} = conn
    # ...
  end

0.3.3 (2026-02-22)

• Fixup Cache key mismatch
• Fixup updating state in async returns
• Fixup running without phoenix_pubsub

0.3.2 (2025-07-04)

• Fix error message referring to wrong arity.
• Allow nil origin when Plug options is set to origins: :all.
• Better error handling when Phantom.Tracker is not in the supervision tree. Phantom.MCP will now emit a Logger warning when Phantom.Tracker can be used, but is not in the supervision tree.
• Fix terminate bug introduced in 0.3.1

0.3.1 (2025-07-03)

• Add [:phantom, :plug, :request, :terminate] telemetry event.
• Improve docs

0.3.0 (2025-06-29)

• Move logging functions from Phantom.Session into Phantom.ClientLogger.
• Rename Phantom.Tracker functions to be clearer and more straightforward.
• Consolidate distributed logic into Phantom.Tracker such as PubSub topics.
• Add ability to add tools, prompts, resources in runtime easily. You can call Phantom.Cache.add_tool(router_module, tool_spec). The spec can be built with Phantom.Tool.build/1, the function takes a very similar shape to the corresponding macro from Phantom.MCP.Router. This will also trigger notifications to clients of tool or prompt list updates.
• Handle paginatin for 100+ tools and prompts.
• Change connect/2 callback to receive request headers and query params from the Plug adapter. The signature is now %{headers: list({header, value}), params: map()} where before it was just list({header, value}).
• Phantom.Tool.build, Phantom.Prompt.build and Phantom.ResourceTemplate.build now do more and the Phantom.Router macros do less. This is so runtime can have a consistent experience with compiled declarations. For example, you may Phantom.ResourceTemplate.build(...) with the same arguments as you would with the router macros, and then call Phantom.Cache.add_resource_template(...) and have the same affect as using the resource ... macro in a Phantom.Router router.
• Fixed building tool annontations.
• Fixed resource subscription response and implemented unsubscribe method.
• Improve documentation

0.2.3 (2025-06-24)

• Fix the initialize request status code and headers. In 0.2.2 it worked with mcp-inspector but not with Claude Desktop or Zed. Now it works with all.

0.2.2 (2025-06-22)

• Fix the initialize request. It should have kept the SSE stream open.
• Fix bugs

0.2.1 (2025-06-21)

• Fix default list_resources/2 callback and default implementation.

0.2.0 (2025-06-17)

Phantom MCP released!