Helps with #7853: Switch representation in bulk on selected objects

For non-active objects, match both ContextOfItems and
RepresentationIdentifier (e.g. 'Body', 'Axis') against
the active object's target representation. Previously only
ContextOfItems was compared, causing all objects sharing
the same parent context to be skipped incorrectly.

Also pass disable_opening_subtractions to core, which was
previously declared but never forwarded.

Generated with the assistance of an AI coding tool.

.github/workflows/ci-bonsai-daily.yml

@@ -109,7 +109,7 @@ jobs:
           # Ensure Bonsai and ifcsverchok enable/disable works before uploading to extensions repo.
 
           # Download Blender.
-          wget -q -O blender.tar.xz https://download.blender.org/release/Blender5.0/blender-5.1.0-linux-x64.tar.xz
+          wget -q -O blender.tar.xz https://download.blender.org/release/Blender5.1/blender-5.1.0-linux-x64.tar.xz
           tar -xf blender.tar.xz
 
           # Setup Blender.
@@ -122,7 +122,7 @@ jobs:
           pip install -r requirements.txt
           python setup_extensions_repo.py --last-tag
           cd ..
-          bonsai_zip="$(pwd)/$(ls bonsai_unstable_repo/bonsai_py311*-linux-x64.zip)"
+          bonsai_zip="$(pwd)/$(ls bonsai_unstable_repo/bonsai_py313*-linux-x64.zip)"
 
           # Install Bonsai.
           blender --command extension install-file -r user_default -e $bonsai_zip

src/bonsai/bonsai/bim/module/aggregate/prop.py

@@ -73,6 +73,22 @@ def poll_related_object(self: "BIMObjectAggregateProperties", related_obj: bpy.t
     return True
 
 
+def update_relating_object(self, context):
+    if self.relating_object:
+        ifc_id = tool.Blender.get_object_bim_props(self.relating_object).ifc_definition_id
+        if ifc_id:
+            bpy.ops.bim.aggregate_assign_object(relating_object=ifc_id)
+            bpy.ops.bim.disable_editing_aggregate()
+
+
+def update_related_object(self, context):
+    if self.related_object:
+        ifc_id = tool.Blender.get_object_bim_props(self.related_object).ifc_definition_id
+        if ifc_id:
+            bpy.ops.bim.aggregate_assign_object(related_object=ifc_id)
+            bpy.ops.bim.disable_editing_aggregate()
+
+
 def update_aggregate_decorator(self, context):
     if self.aggregate_decorator:
         AggregateDecorator.install(bpy.context)
@@ -89,12 +105,15 @@ def update_aggregate_mode_decorator(self, context):
 
 class BIMObjectAggregateProperties(PropertyGroup):
     is_editing: BoolProperty(name="Is Editing")
-    relating_object: PointerProperty(name="Relating Whole", type=bpy.types.Object, poll=poll_relating_object)
+    relating_object: PointerProperty(
+        name="Relating Whole", type=bpy.types.Object, poll=poll_relating_object, update=update_relating_object
+    )
     related_object: PointerProperty(
         name="Related Part",
         description="Related Part, will be used to derive the Relating Object",
         type=bpy.types.Object,
         poll=poll_related_object,
+        update=update_related_object,
     )
 
     if TYPE_CHECKING:

src/bonsai/bonsai/bim/module/geometry/operator.py

@@ -445,22 +445,35 @@ class SwitchRepresentation(bpy.types.Operator, tool.Ifc.Operator):
     def _execute(self, context):
         provided_representation = tool.Ifc.get().by_id(self.ifc_definition_id)
         ifc_context = provided_representation.ContextOfItems
+        provided_identifier = provided_representation.RepresentationIdentifier
         for obj in tool.Blender.get_selected_objects():
             if not (element := tool.Ifc.get_entity(obj)) or obj.mode != "OBJECT":
                 continue
 
-            # Find representation to switch to.
-            if (active_representation := tool.Geometry.get_active_representation(obj)) is None:
+            active_representation = tool.Geometry.get_active_representation(obj)
+
+            if obj == context.active_object:
+                representation = provided_representation
+            elif active_representation is None:
                 # No active representation => probably has no representations.
                 continue
-            elif obj == context.active_object:
-                # Prioritize provided representation.
-                representation = provided_representation
-            elif active_representation.ContextOfItems == ifc_context:
-                # Prioritize already active representation if context matches.
-                representation = active_representation
+            elif (
+                active_representation.ContextOfItems == ifc_context
+                and active_representation.RepresentationIdentifier == provided_identifier
+            ):
+                # Already showing the correct representation — no geometry update needed.
+                continue
             else:
-                representation = ifcopenshell.util.representation.get_representation(element, ifc_context)
+                # Find a representation matching both the context and identifier.
+                representation = next(
+                    (
+                        r
+                        for r in ifcopenshell.util.representation.get_representations_iter(element)
+                        if r.ContextOfItems == ifc_context
+                        and r.RepresentationIdentifier == provided_identifier
+                    ),
+                    None,
+                )
                 if not representation:
                     continue
 
@@ -469,6 +482,7 @@ class SwitchRepresentation(bpy.types.Operator, tool.Ifc.Operator):
                 tool.Geometry,
                 obj=obj,
                 representation=representation,
+                apply_openings=not self.disable_opening_subtractions,
             )
 
 

src/bonsai/bonsai/tool/raycast.py

@@ -434,11 +434,8 @@ class Raycast(bonsai.core.tool.Raycast):
             seg_len_sq = sx * sx + sy * sy
 
             if seg_len_sq == 0.0:
-                # degenerate segment: return distance to p0
-                dx = px - p0x
-                dy = py - p0y
-                dist = math.hypot(dx, dy)
-                return dist, (p0x, p0y), 0.0
+                # degenerate segment: skip it
+                continue
 
             # project (p - p0) onto seg: t = dot(p-p0, seg) / |seg|^2
             apx = px - p0x
@@ -892,8 +889,19 @@ class Raycast(bonsai.core.tool.Raycast):
     def create_snap_obj(cls, obj):
         if obj.data is None or not isinstance(obj.data, bpy.types.Mesh):
             return None
-        for snap_obj in cls.snap_objs:
+        for i, snap_obj in enumerate(cls.snap_objs):
             if obj.name == snap_obj.obj.name:
+                # Handle objects modified while a modal operator is active.
+                # Example: adding a door or window alters the wall geometry.
+                if len(obj.data.vertices) != len(snap_obj.verts_3d):
+                    cls.snap_objs.pop(i)
+                    snap_obj = SnapObj(obj)
+                    cls.snap_objs.append(snap_obj)
+                for v1, v2 in zip(obj.data.vertices, snap_obj.verts_3d):
+                    if (obj.matrix_world @ v1.co) != v2:
+                        cls.snap_objs.pop(i)
+                        snap_obj = SnapObj(obj)
+                        cls.snap_objs.append(snap_obj)
                 return snap_obj
         snap_obj = SnapObj(obj)
         cls.snap_objs.append(snap_obj)

src/ifcchat/CNAME

@@ -0,0 +1 @@
+ai-chat.ifcopenshell.org

src/ifcchat/README.md

@@ -1,7 +1,7 @@
 IfcOpenShell AI Assistant 
 =========================
 
-A web-based client-side (pyodide + OpenAI API) model interrogation and generation API based on: ifcedit, ifcquery and ifcmcp (ifcopenshell-mcp) packaged in a HTML+JS application.
+A web-based client-side (pyodide + OpenAI, Anthropic, Gemini, or OpenRouter API) model interrogation and generation API based on: ifcedit, ifcquery and ifcmcp (ifcopenshell-mcp) packaged in a HTML+JS application.
 
 ### Setup instructions
 

src/ifcchat/api_anthropic.js

@@ -0,0 +1,184 @@
+// This file was generated with the assistance of an AI coding tool.
+
+function parseArguments(argumentsText) {
+    if (!argumentsText) return {};
+    try {
+        return JSON.parse(argumentsText);
+    } catch {
+        return {};
+    }
+}
+
+function toAnthropicTools(tools = []) {
+    return tools.map((tool) => ({
+        name: tool.function.name,
+        description: tool.function.description,
+        input_schema: tool.function.parameters,
+    }));
+}
+
+function toAnthropicAssistantContent(message) {
+    const content = [];
+
+    if (message.content) {
+        content.push({ type: "text", text: message.content });
+    }
+
+    for (const toolCall of message.tool_calls ?? []) {
+        content.push({
+            type: "tool_use",
+            id: toolCall.id,
+            name: toolCall.function.name,
+            input: parseArguments(toolCall.function.arguments),
+        });
+    }
+
+    if (content.length === 0) {
+        return "";
+    }
+
+    return content.length === 1 && content[0].type === "text" ? content[0].text : content;
+}
+
+function toAnthropicUserContent(message) {
+    return typeof message.content === "string" ? message.content : JSON.stringify(message.content ?? "");
+}
+
+function toAnthropicToolResult(message) {
+    return {
+        type: "tool_result",
+        tool_use_id: message.tool_call_id,
+        content: typeof message.content === "string" ? message.content : JSON.stringify(message.content ?? ""),
+    };
+}
+
+function splitSystemAndMessages(messages = []) {
+    const system = [];
+    const anthropicMessages = [];
+    let pendingToolResults = [];
+
+    const flushToolResults = () => {
+        if (pendingToolResults.length === 0) return;
+        anthropicMessages.push({ role: "user", content: pendingToolResults });
+        pendingToolResults = [];
+    };
+
+    for (const message of messages) {
+        if (message.role === "system") {
+            if (message.content) {
+                system.push(message.content);
+            }
+            continue;
+        }
+
+        if (message.role === "tool") {
+            pendingToolResults.push(toAnthropicToolResult(message));
+            continue;
+        }
+
+        flushToolResults();
+
+        if (message.role === "user") {
+            anthropicMessages.push({
+                role: "user",
+                content: toAnthropicUserContent(message),
+            });
+            continue;
+        }
+
+        if (message.role === "assistant") {
+            anthropicMessages.push({
+                role: "assistant",
+                content: toAnthropicAssistantContent(message),
+            });
+        }
+    }
+
+    flushToolResults();
+
+    return {
+        system: system.join("\n\n"),
+        messages: anthropicMessages,
+    };
+}
+
+function toChatCompletionResponse(response) {
+    const text = [];
+    const toolCalls = [];
+
+    for (const block of response.content ?? []) {
+        if (block.type === "text") {
+            text.push(block.text);
+            continue;
+        }
+
+        if (block.type === "tool_use") {
+            toolCalls.push({
+                id: block.id,
+                type: "function",
+                function: {
+                    name: block.name,
+                    arguments: JSON.stringify(block.input ?? {}),
+                },
+            });
+        }
+    }
+
+    const message = { role: "assistant" };
+    const content = text.join("\n").trim();
+
+    if (content) {
+        message.content = content;
+    }
+
+    if (toolCalls.length) {
+        message.tool_calls = toolCalls;
+    }
+
+    return {
+        choices: [
+            {
+                message,
+            },
+        ],
+    };
+}
+
+export async function chat({ apiKey, model, messages, tools }) {
+    const request = splitSystemAndMessages(messages);
+    const anthropicTools = toAnthropicTools(tools);
+
+    // Mark the last tool with cache_control so the entire tool list is cached
+    if (anthropicTools.length > 0) {
+        anthropicTools[anthropicTools.length - 1].cache_control = { type: "ephemeral" };
+    }
+
+    const body = {
+        model,
+        max_tokens: 4096,
+        messages: request.messages,
+        tools: anthropicTools,
+    };
+
+    if (request.system) {
+        body.system = [{ type: "text", text: request.system, cache_control: { type: "ephemeral" } }];
+    }
+
+    const res = await fetch("https://api.anthropic.com/v1/messages", {
+        method: "POST",
+        headers: {
+            "Content-Type": "application/json",
+            "x-api-key": apiKey,
+            "anthropic-version": "2023-06-01",
+            "anthropic-dangerous-direct-browser-access": "true",
+        },
+        body: JSON.stringify(body),
+    });
+
+    if (!res.ok) {
+        const text = await res.text();
+        throw new Error(`Anthropic error ${res.status}: ${text}`);
+    }
+
+    return toChatCompletionResponse(await res.json());
+}

src/ifcchat/api_openai.js

@@ -0,0 +1,20 @@
+function getChatCompletionsUrl(baseURL) {
+    const root = (baseURL || "https://api.openai.com/v1").replace(/\/+$/, "");
+    return `${root}/chat/completions`;
+}
+
+export async function chat({ apiKey, baseURL, model, messages, tools }) {
+    const res = await fetch(getChatCompletionsUrl(baseURL), {
+        method: "POST",
+        headers: {
+            "Content-Type": "application/json",
+            "Authorization": `Bearer ${apiKey}`,
+        },
+        body: JSON.stringify({ model, messages, tools }),
+    });
+    if (!res.ok) {
+        const text = await res.text();
+        throw new Error(`OpenAI error ${res.status}: ${text}`);
+    }
+    return await res.json();
+}

src/ifcchat/api_openrouter.js

@@ -0,0 +1,20 @@
+function getChatCompletionsUrl(baseURL) {
+    const root = (baseURL || "https://openrouter.ai/api/v1").replace(/\/+$/, "");
+    return `${root}/chat/completions`;
+}
+
+export async function chat({ apiKey, baseURL, model, messages, tools }) {
+    const res = await fetch(getChatCompletionsUrl(baseURL), {
+        method: "POST",
+        headers: {
+            "Content-Type": "application/json",
+            "Authorization": `Bearer ${apiKey}`,
+        },
+        body: JSON.stringify({ model, messages, tools }),
+    });
+    if (!res.ok) {
+        const text = await res.text();
+        throw new Error(`OpenRouter error ${res.status}: ${text}`);
+    }
+    return await res.json();
+}

src/ifcchat/app.js

@@ -1,4 +1,132 @@
 // app.js
+import * as openaiApi from "./api_openai.js";
+import * as anthropicApi from "./api_anthropic.js";
+import * as openrouterApi from "./api_openrouter.js";
+
+const PROVIDERS = {
+    openai: {
+        api: openaiApi,
+        apiKeyLabel: "OpenAI API key",
+        apiKeyPlaceholder: "sk-...",
+        baseUrlLabel: "Base URL",
+        baseUrlPlaceholder: "https://api.openai.com/v1",
+        baseUrlDefault: "https://api.openai.com/v1",
+        models: [
+            {
+                value: "gpt-5.2",
+                label: "gpt-5.2"
+            },
+            {
+                value: "gpt-5.2-chat-latest",
+                label: "gpt-5.2-chat-latest"
+            },
+            {
+                value: "gpt-5",
+                label: "gpt-5"
+            },
+            {
+                value: "gpt-5-chat-latest",
+                label: "gpt-5-chat-latest"
+            },
+            {
+                value: "gpt-5-mini",
+                label: "gpt-5-mini"
+            },
+            {
+                value: "gpt-5-nano",
+                label: "gpt-5-nano"
+            },
+            {
+                value: "gpt-4.1",
+                label: "gpt-4.1"
+            },
+            {
+                value: "gpt-4.1-mini",
+                label: "gpt-4.1-mini"
+            },
+            {
+                value: "gpt-4.1-nano",
+                label: "gpt-4.1-nano"
+            },
+        ],
+    },
+    anthropic: {
+        api: anthropicApi,
+        apiKeyLabel: "Anthropic API key",
+        apiKeyPlaceholder: "sk-ant-...",
+        models: [
+            {
+                value: "claude-sonnet-4-6",
+                label: "claude-sonnet-4-6"
+            },
+            {
+                value: "claude-opus-4-6",
+                label: "claude-opus-4-6"
+            },
+            {
+                value: "claude-haiku-4-5-20251001",
+                label: "claude-haiku-4-5"
+            },
+        ],
+    },
+    gemini: {
+        api: openaiApi,
+        apiKeyLabel: "Gemini API key",
+        apiKeyPlaceholder: "AIza...",
+        baseUrlLabel: "Base URL",
+        baseUrlPlaceholder: "https://generativelanguage.googleapis.com/v1beta/openai/",
+        baseUrlDefault: "https://generativelanguage.googleapis.com/v1beta/openai/",
+        models: [
+            {
+                value: "gemini-3-flash-preview",
+                label: "gemini-3-flash-preview"
+            },
+            {
+                value: "gemini-2.5-flash",
+                label: "gemini-2.5-flash"
+            },
+            {
+                value: "gemini-2.5-pro",
+                label: "gemini-2.5-pro"
+            },
+        ],
+    },
+    openrouter: {
+        api: openrouterApi,
+        apiKeyLabel: "OpenRouter API key",
+        apiKeyPlaceholder: "sk-or-v1-...",
+        baseUrlLabel: "Base URL",
+        baseUrlPlaceholder: "https://openrouter.ai/api/v1",
+        baseUrlDefault: "https://openrouter.ai/api/v1",
+        models: [
+            { 
+                value: "openai/gpt-oss-20b",
+                label: "gpt-oss-20b" 
+            },
+            { 
+                value: "openai/gpt-oss-120b",
+                label: "gpt-oss-120b" 
+            },
+            { 
+                value: "mistralai/mistral-small-3.2-24b-instruct",
+                label: "mistral-small-3.2" 
+            },
+            { 
+                value: "openai/gpt-4.1",                    
+                label: "gpt-4.1" 
+            },
+            { 
+                value: "anthropic/claude-sonnet-4-5",       
+                label: "claude-sonnet-4-5" 
+            },
+            { 
+                value: "google/gemini-2.5-pro-preview",     
+                label: "gemini-2.5-pro" 
+            },
+        ],
+    },
+};
+
 const $ = (id) => document.getElementById(id);
 
 const statusEl = $("status");
@@ -6,11 +134,42 @@ const msgsEl = $("msgs");
 const sendBtn = $("send");
 const inputEl = $("input");
 const apiKeyEl = $("apiKey");
+const apiKeyLabelEl = $("apiKeyLabel");
+const baseUrlRowEl = $("baseUrlRow");
+const baseUrlLabelEl = $("baseUrlLabel");
+const baseUrlEl = $("baseUrl");
+const thinkingIndicatorEl = $("thinkingIndicator");
 const modelEl = $("model");
+const providerEls = document.querySelectorAll('input[name="provider"]');
 const ifcFileEl = $("ifcFile");
 const newBtn = $("newModel");
 const downloadBtn = $("downloadIfc");
 
+function getProviderValue() {
+    return document.querySelector('input[name="provider"]:checked')?.value || "openai";
+}
+
+function onProviderChange() {
+    const provider = PROVIDERS[getProviderValue()];
+    apiKeyLabelEl.innerHTML = `${provider.apiKeyLabel}<span class="small">stored in browser memory; only sent to provider servers</span>`;
+    apiKeyEl.placeholder = provider.apiKeyPlaceholder;
+    baseUrlRowEl.hidden = !provider.baseUrlDefault;
+    if (provider.baseUrlDefault) {
+        baseUrlLabelEl.innerHTML = `${provider.baseUrlLabel}<span class="small">override the API endpoint for OpenAI-compatible providers</span>`;
+        baseUrlEl.placeholder = provider.baseUrlPlaceholder;
+        baseUrlEl.value = provider.baseUrlDefault;
+    } else {
+        baseUrlEl.value = "";
+        baseUrlEl.placeholder = "";
+    }
+    modelEl.innerHTML = provider.models.map(m => `<option value="${m.value}">${m.label}</option>`).join("");
+}
+
+for (const providerEl of providerEls) {
+    providerEl.addEventListener("change", onProviderChange);
+}
+onProviderChange();
+
 function setBusy(isBusy, reason = "") {
     const controls = [
         $("send"),
@@ -30,32 +189,213 @@ function setBusy(isBusy, reason = "") {
         browseBtn.tabIndex = isBusy ? -1 : 0;
     }
 
+    sendBtn.innerHTML = isBusy
+        ? `<span class="spinner"></span>`
+        : `Send <span class="material-icons">send</span>`;
+
     setStatus(isBusy ? (reason || "Working…") : "Ready");
 }
 
+function escapeHtml(text) {
+    return text
+        .replaceAll("&", "&amp;")
+        .replaceAll("<", "&lt;")
+        .replaceAll(">", "&gt;")
+        .replaceAll('"', "&quot;")
+        .replaceAll("'", "&#39;");
+}
+
+function sanitizeUrl(url) {
+    try {
+        const parsed = new URL(url, window.location.href);
+        if (["http:", "https:", "mailto:"].includes(parsed.protocol)) {
+            return parsed.href;
+        }
+    } catch {
+    }
+    return null;
+}
+
+function renderInlineMarkdown(text) {
+    const placeholders = [];
+    const addPlaceholder = (html) => {
+        const token = `@@MD${placeholders.length}@@`;
+        placeholders.push({ token, html });
+        return token;
+    };
+
+    let rendered = text;
+
+    rendered = rendered.replace(/`([^`]+)`/g, (_, code) => addPlaceholder(`<code>${escapeHtml(code)}</code>`));
+    rendered = rendered.replace(/\[([^\]]+)\]\(([^)\s]+)\)/g, (_, label, url) => {
+        const href = sanitizeUrl(url);
+        if (!href) {
+            return `${label} (${url})`;
+        }
+        return addPlaceholder(
+            `<a href="${escapeHtml(href)}" target="_blank" rel="noreferrer noopener">${escapeHtml(label)}</a>`
+        );
+    });
+
+    rendered = escapeHtml(rendered);
+    rendered = rendered.replace(/\*\*([^*]+)\*\*/g, "<strong>$1</strong>");
+    rendered = rendered.replace(/\*([^*]+)\*/g, "<em>$1</em>");
+    rendered = rendered.replace(/_([^_]+)_/g, "<em>$1</em>");
+
+    for (const placeholder of placeholders) {
+        rendered = rendered.replaceAll(placeholder.token, placeholder.html);
+    }
+
+    return rendered;
+}
+
+function renderMarkdown(text) {
+    const lines = String(text).replace(/\r\n?/g, "\n").split("\n");
+    const html = [];
+    let paragraphLines = [];
+    let quoteLines = [];
+    let listType = null;
+    let listItems = [];
+
+    const flushParagraph = () => {
+        if (!paragraphLines.length) return;
+        html.push(`<p>${renderInlineMarkdown(paragraphLines.join(" "))}</p>`);
+        paragraphLines = [];
+    };
+
+    const flushQuote = () => {
+        if (!quoteLines.length) return;
+        const quoteBody = quoteLines.map((line) => renderInlineMarkdown(line)).join("<br />");
+        html.push(`<blockquote><p>${quoteBody}</p></blockquote>`);
+        quoteLines = [];
+    };
+
+    const flushList = () => {
+        if (!listItems.length || !listType) return;
+        const items = listItems.map((item) => `<li>${renderInlineMarkdown(item)}</li>`).join("");
+        html.push(`<${listType}>${items}</${listType}>`);
+        listType = null;
+        listItems = [];
+    };
+
+    const flushAll = () => {
+        flushParagraph();
+        flushQuote();
+        flushList();
+    };
+
+    for (let index = 0; index < lines.length; index++) {
+        const line = lines[index];
+        const trimmed = line.trim();
+
+        if (trimmed.startsWith("```")) {
+            flushAll();
+            const language = trimmed.slice(3).trim();
+            const codeLines = [];
+            index += 1;
+            while (index < lines.length && !lines[index].trim().startsWith("```")) {
+                codeLines.push(lines[index]);
+                index += 1;
+            }
+            const languageClass = language ? ` class="language-${escapeHtml(language)}"` : "";
+            html.push(`<pre><code${languageClass}>${escapeHtml(codeLines.join("\n"))}</code></pre>`);
+            continue;
+        }
+
+        if (!trimmed) {
+            flushAll();
+            continue;
+        }
+
+        const headingMatch = trimmed.match(/^(#{1,6})\s+(.+)$/);
+        if (headingMatch) {
+            flushAll();
+            const level = headingMatch[1].length;
+            html.push(`<h${level}>${renderInlineMarkdown(headingMatch[2])}</h${level}>`);
+            continue;
+        }
+
+        const quoteMatch = trimmed.match(/^>\s?(.*)$/);
+        if (quoteMatch) {
+            flushParagraph();
+            flushList();
+            quoteLines.push(quoteMatch[1]);
+            continue;
+        }
+
+        if (quoteLines.length) {
+            flushQuote();
+        }
+
+        const unorderedListMatch = trimmed.match(/^[-*]\s+(.+)$/);
+        if (unorderedListMatch) {
+            flushParagraph();
+            if (listType && listType !== "ul") {
+                flushList();
+            }
+            listType = "ul";
+            listItems.push(unorderedListMatch[1]);
+            continue;
+        }
+
+        const orderedListMatch = trimmed.match(/^\d+\.\s+(.+)$/);
+        if (orderedListMatch) {
+            flushParagraph();
+            if (listType && listType !== "ol") {
+                flushList();
+            }
+            listType = "ol";
+            listItems.push(orderedListMatch[1]);
+            continue;
+        }
+
+        if (listItems.length) {
+            flushList();
+        }
+
+        paragraphLines.push(trimmed);
+    }
+
+    flushAll();
+
+    return html.join("");
+}
+
 function addMessage(role, text) {
     if (text.ok) {
         text = text.data;
     }
+    if (typeof text !== "string") {
+        text = JSON.stringify(text, null, 2);
+    }
     const wrap = document.createElement("div");
     wrap.className = `msg ${role}`;
     wrap.innerHTML = `
-    <div class="role ${role}">${role}</div>
+    <div class="role ${role}">${role}${role === "tool" ? '<span class="chevron">▶</span>' : ''}</div>
     <div class="bubble"></div>`;
     const bubble = wrap.querySelector(".bubble");
-    bubble.textContent = text;
+    if (role === "assistant") {
+        bubble.classList.add("markdown-content");
+        bubble.innerHTML = renderMarkdown(text);
+    } else {
+        bubble.textContent = text;
+    }
     bubble.onclick = function () {
         if (bubble.scrollHeight > 100 && role === "tool") {
-            bubble.style.maxHeight = bubble.style.maxHeight == 'none' ? '' : 'none';
-            bubble.style.borderBottom = bubble.style.borderBottom == '' ? 'dotted 2px gray' : '';
+            const expanded = bubble.style.maxHeight === 'none';
+            bubble.style.maxHeight = expanded ? '' : 'none';
+            bubble.style.borderBottom = expanded ? '' : 'dotted 2px gray';
+            wrap.querySelector(".chevron").style.transform = expanded ? '' : 'rotate(90deg)';
         }
     }
-    msgsEl.appendChild(wrap);
+    msgsEl.insertBefore(wrap, thinkingIndicatorEl);
     msgsEl.scrollTop = msgsEl.scrollHeight;
 }
 
 function setStatus(text) {
     statusEl.textContent = text;
+    thinkingIndicatorEl.hidden = text !== "Thinking…";
+    msgsEl.scrollTop = msgsEl.scrollHeight;
 }
 
 const worker = new Worker("./ifc_worker.js", { type: "module" });
@@ -75,74 +415,73 @@ function callWorker(type, payload = {}) {
     });
 }
 
-// ---- OpenAI Responses API tool schemas (should match ifcmcp.core openai_tools()) ----
-// Docs show Responses API function_call items + function_call_output loop. :contentReference[oaicite:4]{index=4}
+// ---- Tool schemas (should match ifcmcp.core openai_tools()) ----
 const tools = [
     {
-        type: "function", name: "ifc_new", description: "Create a new empty IFC model in memory.",
-        parameters: { type: "object", properties: { schema: { type: "string" } }, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_new", description: "Create a new empty IFC model in memory. Valid schemas: IFC4, IFC2X3, IFC4X3 (for IFC 4.3).",
+        parameters: { type: "object", properties: { schema: { type: "string", enum: ["IFC4", "IFC2X3", "IFC4X3"] } }, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_summary", description: "Get a concise overview of the loaded IFC model.",
-        parameters: { type: "object", properties: {}, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_summary", description: "Get a concise overview of the loaded IFC model.",
+        parameters: { type: "object", properties: {}, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_tree", description: "Get the full spatial hierarchy tree.",
-        parameters: { type: "object", properties: {}, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_tree", description: "Get the full spatial hierarchy tree.",
+        parameters: { type: "object", properties: {}, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_select", description: "Select elements using ifcopenshell selector syntax (e.g. 'IfcWall').",
-        parameters: { type: "object", properties: { query: { type: "string" } }, required: ["query"], additionalProperties: false }
+        type: "function", function: { name: "ifc_select", description: "Select elements using ifcopenshell selector syntax (e.g. 'IfcWall').",
+        parameters: { type: "object", properties: { query: { type: "string" } }, required: ["query"], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_info", description: "Inspect an entity by STEP id.",
-        parameters: { type: "object", properties: { element_id: { type: "integer" } }, required: ["element_id"], additionalProperties: false }
+        type: "function", function: { name: "ifc_info", description: "Inspect an entity by STEP id.",
+        parameters: { type: "object", properties: { element_id: { type: "integer" } }, required: ["element_id"], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_relations", description: "Get relationships for an element. traverse='up' walks to IfcProject.",
+        type: "function", function: { name: "ifc_relations", description: "Get relationships for an element. traverse='up' walks to IfcProject.",
         parameters: {
             type: "object", properties: { element_id: { type: "integer" }, traverse: { type: "string" } },
             required: ["element_id"], additionalProperties: false
-        }
+        } }
     },
     {
-        type: "function", name: "ifc_clash", description: "Run clash/clearance checks for an element.",
+        type: "function", function: { name: "ifc_clash", description: "Run clash/clearance checks for an element.",
         parameters: {
             type: "object", properties: { element_id: { type: "integer" }, clearance: { type: "number" }, tolerance: { type: "number" }, scope: { type: "string" } },
             required: ["element_id"], additionalProperties: false
-        }
+        } }
     },
     {
-        type: "function", name: "ifc_list", description: "List ifcopenshell.api modules or functions within a module.",
-        parameters: { type: "object", properties: { module: { type: "string" } }, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_list", description: "List ifcopenshell.api modules or functions within a module.",
+        parameters: { type: "object", properties: { module: { type: "string" } }, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_docs", description: "Get documentation for an ifcopenshell.api function, 'module.function'.",
-        parameters: { type: "object", properties: { function_path: { type: "string" } }, required: ["function_path"], additionalProperties: false }
+        type: "function", function: { name: "ifc_docs", description: "Get documentation for an ifcopenshell.api function, 'module.function'.",
+        parameters: { type: "object", properties: { function_path: { type: "string" } }, required: ["function_path"], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_edit", description: "Execute an ifcopenshell.api mutation; params is a JSON string of stringly-typed kwargs.",
-        parameters: { type: "object", properties: { function_path: { type: "string" }, params: { type: "string" } }, required: ["function_path"], additionalProperties: false }
+        type: "function", function: { name: "ifc_edit", description: "Execute an ifcopenshell.api mutation; params is a JSON string of stringly-typed kwargs.",
+        parameters: { type: "object", properties: { function_path: { type: "string" }, params: { type: "string" } }, required: ["function_path"], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_validate", description: "Validate the loaded model. Returns valid bool and list of issues.",
-        parameters: { type: "object", properties: { express_rules: { type: "boolean" } }, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_validate", description: "Validate the loaded model. Returns valid bool and list of issues.",
+        parameters: { type: "object", properties: { express_rules: { type: "boolean" } }, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_schedule", description: "List work schedules and nested tasks. Use max_depth=1 for top-level phases only on large projects.",
-        parameters: { type: "object", properties: { max_depth: { type: "integer" } }, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_schedule", description: "List work schedules and nested tasks. Use max_depth=1 for top-level phases only on large projects.",
+        parameters: { type: "object", properties: { max_depth: { type: "integer" } }, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_cost", description: "List cost schedules and nested cost items. Use max_depth=1 for top-level sections only on large BoQs.",
-        parameters: { type: "object", properties: { max_depth: { type: "integer" } }, required: [], additionalProperties: false }
+        type: "function", function: { name: "ifc_cost", description: "List cost schedules and nested cost items. Use max_depth=1 for top-level sections only on large BoQs.",
+        parameters: { type: "object", properties: { max_depth: { type: "integer" } }, required: [], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_schema", description: "Return IFC class documentation for an entity type.",
-        parameters: { type: "object", properties: { entity_type: { type: "string" } }, required: ["entity_type"], additionalProperties: false }
+        type: "function", function: { name: "ifc_schema", description: "Return IFC class documentation for an entity type.",
+        parameters: { type: "object", properties: { entity_type: { type: "string" } }, required: ["entity_type"], additionalProperties: false } }
     },
     {
-        type: "function", name: "ifc_quantify", description: "Run quantity take-off (QTO) on the model. Modifies model in-place; call ifc_save() after.",
-        parameters: { type: "object", properties: { rule: { type: "string" }, selector: { type: "string" } }, required: ["rule"], additionalProperties: false }
+        type: "function", function: { name: "ifc_quantify", description: "Run quantity take-off (QTO) on the model. Modifies model in-place; call ifc_save() after.",
+        parameters: { type: "object", properties: { rule: { type: "string" }, selector: { type: "string" } }, required: ["rule"], additionalProperties: false } }
     },
 ];
 
@@ -156,85 +495,78 @@ Rules:
 Be concise. Avoid dumping huge trees unless asked.
 `;
 
-let inputItems = []; // running conversation state (Responses API style)
+let messages = []; // running conversation state (Chat Completions style)
 
-async function openAIResponsesCreate({ apiKey, model, input, tools }) {
-    const res = await fetch("https://api.openai.com/v1/responses", {
-        method: "POST",
-        headers: {
-            "Content-Type": "application/json",
-            "Authorization": `Bearer ${apiKey}`,
-        },
-        body: JSON.stringify({
-            model,
-            instructions: SYSTEM_INSTRUCTIONS,
-            tools,
-            input,
-        }),
-    });
+const MAX_TOOL_RESULT_CHARS = 0;
+const MAX_HISTORY_MESSAGES = 40;
 
-    if (!res.ok) {
-        const text = await res.text();
-        throw new Error(`OpenAI error ${res.status}: ${text}`);
-    }
-    return await res.json();
+function truncateToolResult(text) {
+    if (MAX_TOOL_RESULT_CHARS == 0 || text.length <= MAX_TOOL_RESULT_CHARS) return text;
+    return text.slice(0, MAX_TOOL_RESULT_CHARS) + "\n... (truncated)";
 }
 
-function extractAssistantText(response) {
-    const out = [];
-    for (const item of response.output ?? []) {
-        if (item.type === "message" && item.role === "assistant") {
-            for (const c of item.content ?? []) {
-                if (c.type === "output_text") out.push(c.text);
-            }
-        }
+function trimHistory() {
+    if (messages.length <= MAX_HISTORY_MESSAGES) return;
+    // Find a safe cut point — don't break mid-tool-call sequence.
+    // Walk forward from the trim target to find a user message boundary.
+    let cut = messages.length - MAX_HISTORY_MESSAGES;
+    while (cut < messages.length && messages[cut].role !== "user") {
+        cut++;
+    }
+    if (cut > 0 && cut < messages.length) {
+        messages.splice(0, cut);
     }
-    return out.join("\n").trim();
 }
 
 async function runAgentTurn(userText) {
     const apiKey = apiKeyEl.value.trim();
     if (!apiKey) throw new Error("Missing API key");
 
-    // Add user message
-    inputItems.push({ role: "user", content: userText });
+    const provider = PROVIDERS[getProviderValue()];
+    const { chat } = provider.api;
+    const baseURL = provider.baseUrlDefault ? baseUrlEl.value.trim() : undefined;
+
+    messages.push({ role: "user", content: userText });
+    trimHistory();
 
-    // Tool-calling loop (Responses API): append response.output, execute function_call items, append function_call_output.
     for (let i = 0; i < 64; i++) {
-        const response = await openAIResponsesCreate({
+        const response = await chat({
             apiKey,
+            baseURL,
             model: modelEl.value,
-            input: inputItems,
+            messages: [{ role: "system", content: SYSTEM_INSTRUCTIONS }, ...messages],
             tools,
         });
 
-        // Keep ALL output items (incl reasoning/tool calls) in the running state.
-        inputItems.push(...(response.output ?? []));
+        const message = response.choices?.[0]?.message;
+        if (!message) throw new Error("No message in response");
 
-        // Show any assistant text immediately
-        const text = extractAssistantText(response);
-        if (text) addMessage("assistant", text);
+        messages.push(message);
 
-        const calls = (response.output ?? []).filter((x) => x.type === "function_call");
+        if (message.content) addMessage("assistant", message.content);
+
+        const calls = message.tool_calls ?? [];
         if (calls.length === 0) return;
 
         for (const call of calls) {
             let args = {};
-            try { args = call.arguments ? JSON.parse(call.arguments) : {}; }
+            try { args = call.function.arguments ? JSON.parse(call.function.arguments) : {}; }
             catch { args = {}; }
 
-            addMessage("tool", `→ ${call.name}(${JSON.stringify(args)})`);
+            addMessage("tool", `→ ${call.function.name}(${JSON.stringify(args)})`);
 
-            const toolRes = await callWorker("toolCall", { name: call.name, args });
+            const toolRes = await callWorker("toolCall", { name: call.function.name, args });
 
-            // Feed tool result back to the model
-            inputItems.push({
-                type: "function_call_output",
-                call_id: call.call_id,
-                output: JSON.stringify(toolRes.result),
+            const fullResult = JSON.stringify(toolRes.result);
+
+            messages.push({
+                role: "tool",
+                tool_call_id: call.id,
+                content: truncateToolResult(fullResult),
             });
 
-            addMessage("tool", `← ${call.name}: ${JSON.stringify(toolRes.result, null, 2)}`);
+            // Show full result in UI, but only truncated version goes to the LLM
+            addMessage("tool", `← ${call.function.name}: ${JSON.stringify(toolRes.result, null, 2)}`);
         }
     }
 
@@ -251,7 +583,7 @@ sendBtn.onclick = async () => {
         await runAgentTurn(text);
         setBusy(false, "Ready");
     } catch (e) {
-        setBusy(true, "Error");
+        setBusy(false, "Error");
         addMessage("assistant", `Error: ${e.message}`);
     }
 };
@@ -281,7 +613,7 @@ ifcFileEl.onchange = async () => {
 newBtn.onclick = async () => {
     try {
         setBusy(true, "Creating new model…");
-        const r = await callWorker("toolCall", { name: "ifc_new", args: { schema: "IFC4" } });
+        const r = await callWorker("toolCall", { name: "ifc_new", args: { schema: "IFC4X3" } });
         addMessage("assistant", `New model: ${JSON.stringify(r.result)}`);
         setBusy(false, "Ready");
     } catch (e) {
@@ -317,4 +649,4 @@ downloadBtn.onclick = async () => {
         setBusy(true, "Error");
         addMessage("assistant", `Worker init failed: ${e.message}`);
     }
-})();
+})();

src/ifcchat/index.html

@@ -5,233 +5,7 @@
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1" />
     <title>IfcOpenShell AI Assistant</title>
-    <style>
-        * {
-            box-sizing: border-box;
-        }
-
-        body {
-            font-family: system-ui, sans-serif;
-            margin: 0;
-        }
-
-        button,
-        input,
-        select,
-        textarea {
-            font: inherit;
-        }
-
-        header {
-            padding: 12px 16px;
-            border-bottom: 1px solid #ddd;
-        }
-
-        header input,
-        header select {
-            padding: 8px;
-        }
-
-        main {
-            display: grid;
-            grid-template-columns: 320px 1fr;
-            height: 100vh;
-        }
-
-        .side {
-            border-right: 1px solid #ddd;
-            padding: 100px 12px 12px 12px;
-            overflow: auto;
-            background: #f9f9f9;
-        }
-
-        .chat {
-            display: flex;
-            flex-direction: column;
-            height: 100%;
-        }
-
-        .msgs {
-            flex: 1;
-            overflow: auto;
-            padding: 16px;
-        }
-
-        .msg {
-            margin: 10px 0;
-        }
-
-        .msg .role {
-            font-size: 12px;
-            opacity: 0.7;
-            margin: 12px 0 4px 0;
-        }
-
-        .role.user {
-            text-align: right;
-        }
-
-        .msg .bubble {
-            padding: 0;
-            border-radius: 10px;
-            white-space: pre-wrap;
-        }
-
-        .msg.user .bubble {
-            padding: 10px 20px;
-            background: #eee;
-            width: 50%;
-            margin-left: auto;
-            border: solid 1px #ddd;
-        }
-
-        .msg.tool .bubble {
-            font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
-            font-size: 60%;
-        }
-
-        .composer {
-            display: flex;
-            gap: 8px;
-            padding: 12px;
-            justify-content: center;
-        }
-
-        .composer textarea {
-            flex: 1;
-            resize: none;
-            height: 88px;
-            border: none;
-        }
-
-        .composer button {
-            align-self: center;
-        }
-
-        .composer .inner {
-            border: solid 1px #ddd;
-            border-radius: 20px;
-            padding: 10px;
-            display: flex;
-            width: 50%;
-        }
-
-        .status {
-            font-size: 12px;
-            opacity: 0.7;
-        }
-
-        section>.row>label {
-            display: block;
-            font-size: 12px;
-            opacity: 0.75;
-            margin-bottom: 6px;
-            font-weight: bold;
-        }
-
-        section>.row>label .small {
-            font-weight: normal;
-            display: block;
-            font-size: 80%;
-        }
-
-        .side .row {
-            margin-bottom: 32px;
-        }
-
-        .row button {
-            padding: 8px 10px;
-        }
-
-        #model {
-            background: white;
-            color: gray;
-            border: solid 1px #eee;
-            border-radius: 6px;
-        }
-
-        hr {
-            border: dashed 1px #ddd;
-        }
-
-        .btn-row {
-            display: flex;
-            gap: 10px;
-        }
-
-        .btn-row>.btn,
-        .btn-row>button.btn {
-            flex: 1 1 0;
-            min-width: 0;
-        }
-
-        .btn {
-            display: inline-flex;
-            align-items: center;
-            justify-content: center;
-            gap: 8px;
-            font-size: 14px;
-
-            padding: 10px 12px;
-            border-radius: 10px;
-            border: 1px solid #d0d0d0;
-            background: #eee;
-
-            cursor: pointer;
-            user-select: none;
-            text-decoration: none;
-        }
-
-        .btn:hover {
-            background: #ddd;
-        }
-
-        .btn:active {
-            transform: translateY(1px);
-        }
-
-        .btn-wide {
-            width: 100%;
-        }
-
-        .material-icons {
-            font-size: 18px;
-            line-height: 1;
-        }
-
-        /* Disabled state for label-button + normal buttons */
-        .btn.disabled,
-        .btn:disabled {
-            opacity: 0.55;
-            cursor: not-allowed;
-            pointer-events: none;
-        }
-
-        .msg.tool .bubble {
-            max-height: 100px;
-            overflow: hidden;
-        }
-
-        #input {
-            border: none;
-            outline: none;
-        }
-
-        #input:focus,
-        #input:focus-visible {
-            outline: none;
-            box-shadow: none;
-        }
-
-        .code {
-            font-family: 'Courier New', Courier, monospace;
-            font-size: 90%;
-            background-color: #eee;
-            border: solid 1px #ddd;
-            padding: 2px;
-            display: inline-block;
-        }
-    </style>
+    <link rel="stylesheet" href="./style.css">
     <link href="https://fonts.googleapis.com/icon?family=Material+Icons" rel="stylesheet">
 </head>
 
@@ -239,14 +13,46 @@
     <main>
         <section class="side">
             <div class="row">
-                <label>OpenAI API key<span class="small">stored in browser memory; only sent to OpenAI servers</span></label>
+                <label>Provider</label>
+                <div class="provider-tabs" role="radiogroup" aria-label="Provider">
+                    <label class="provider-tab">
+                        <input type="radio" name="provider" value="openai" checked />
+                        <span>OpenAI</span>
+                    </label>
+                    <label class="provider-tab">
+                        <input type="radio" name="provider" value="anthropic" />
+                        <span>Claude</span>
+                    </label>
+                    <label class="provider-tab">
+                        <input type="radio" name="provider" value="gemini" />
+                        <span>Gemini</span>
+                    </label>
+                    <label class="provider-tab">
+                        <input type="radio" name="provider" value="openrouter" />
+                        <span>OpenRouter</span>
+                    </label>
+                </div>
+            </div>
+
+            <div class="row">
+                <label>Model</label>
+                <select id="model" style="width: 100%;"></select>
+            </div>
+
+            <div class="row">
+                <label id="apiKeyLabel">API key<span class="small">stored in browser memory; only sent to provider servers</span></label>
                 <input id="apiKey" type="password" placeholder="sk-..." autocomplete="off" style="width: 100%;" />
             </div>
 
+            <div class="row" id="baseUrlRow">
+                <label id="baseUrlLabel">Base URL<span class="small">override the API endpoint for OpenAI-compatible providers</span></label>
+                <input id="baseUrl" type="text" placeholder="https://api.openai.com/v1" autocomplete="off" style="width: 100%;" />
+            </div>
+
             <hr />
 
             <div class="row" style="margin-bottom: 10px;">
-                <label>IFC model context<span class="small">stored in browser memory; only information extracted through MCP commands sent to OpenAI servers</span></label>
+                <label>IFC model context<span class="small">stored in browser memory; only information extracted through MCP commands sent to provider servers</span></label>
 
                 <div class="btn-row">
                     <label class="btn" id="browseBtn" for="ifcFile" role="button" tabindex="0">
@@ -290,15 +96,9 @@
 
         <section class="chat">
             <header>
+                <img src="https://ifcopenshell.org/assets/images/logo.png" style="float: left; padding: 10px 20px 10px 0; ">
                 <div class="row">
-
-                    <img src="https://ifcopenshell.org/assets/images/logo.png" style="float: left; padding: 10px 20px 10px 0; ">
-
                     <strong>IfcOpenShell AI Assistant</strong>
-                    <select id="model">
-                        <option value="gpt-5">gpt-5</option>
-                        <option value="gpt-4.1">gpt-4.1</option>
-                    </select>
                 </div>
                 <div class="row">
 
@@ -306,7 +106,12 @@
                 </div>
             </header>
                 
-            <div class="msgs" id="msgs"></div>
+            <div class="msgs" id="msgs">
+                <div class="thinking-indicator" id="thinkingIndicator" hidden>
+                    <span class="spinner"></span>
+                    <span>thinking...</span>
+                </div>
+            </div>
             <div class="composer">
                 <div class="inner">
                     <textarea id="input" placeholder="Ask or instruct about the IFC model…"></textarea>
@@ -319,4 +124,4 @@
     <script type="module" src="./app.js"></script>
 </body>
 
-</html>
+</html>

src/ifcchat/style.css

@@ -0,0 +1,370 @@
+* {
+    box-sizing: border-box;
+}
+
+body {
+    font-family: system-ui, sans-serif;
+    margin: 0;
+}
+
+button,
+input,
+select,
+textarea {
+    font: inherit;
+}
+
+header {
+    padding: 12px 16px;
+    border-bottom: 1px solid #ddd;
+}
+
+header input,
+header select {
+    padding: 8px;
+}
+
+main {
+    display: grid;
+    grid-template-columns: 320px 1fr;
+    height: 100vh;
+}
+
+.side {
+    border-right: 1px solid #ddd;
+    padding: 12px;
+    overflow: auto;
+    background: #f9f9f9;
+}
+
+.chat {
+    display: flex;
+    flex-direction: column;
+    height: 100%;
+}
+
+.msgs {
+    flex: 1;
+    overflow: auto;
+    padding: 16px;
+}
+
+.msg {
+    margin: 10px 0;
+}
+
+.thinking-indicator {
+    display: inline-flex;
+    align-items: center;
+    gap: 10px;
+    color: #555;
+    font-size: 80%;
+}
+
+.thinking-indicator[hidden] {
+    display: none;
+}
+
+.thinking-indicator .spinner {
+    width: 14px;
+    height: 14px;
+}
+
+.msg .role {
+    font-size: 12px;
+    opacity: 0.7;
+    margin: 12px 0 4px 0;
+}
+
+.role.user {
+    text-align: right;
+}
+
+.msg .bubble {
+    padding: 0;
+    border-radius: 10px;
+    white-space: pre-wrap;
+}
+
+.msg.assistant .bubble {
+    padding: 10px 14px;
+    line-height: 1.5;
+}
+
+.markdown-content > :first-child {
+    margin-top: 0;
+}
+
+.markdown-content > :last-child {
+    margin-bottom: 0;
+}
+
+.markdown-content p,
+.markdown-content ul,
+.markdown-content ol,
+.markdown-content blockquote,
+.markdown-content pre {
+    margin: 0 0 12px 0;
+}
+
+.markdown-content h1,
+.markdown-content h2,
+.markdown-content h3,
+.markdown-content h4,
+.markdown-content h5,
+.markdown-content h6 {
+    margin: 0 0 12px 0;
+    line-height: 1.25;
+}
+
+.markdown-content ul,
+.markdown-content ol {
+    padding-left: 24px;
+}
+
+.markdown-content blockquote {
+    margin-left: 0;
+    padding-left: 12px;
+    border-left: 3px solid #ddd;
+    color: #555;
+}
+
+.markdown-content code {
+    padding: 1px 4px;
+    border-radius: 4px;
+    background: #f2f2f2;
+    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
+    font-size: 90%;
+}
+
+.markdown-content pre {
+    overflow-x: auto;
+    padding: 12px;
+    border-radius: 10px;
+    background: #f4f4f4;
+}
+
+.markdown-content pre code {
+    padding: 0;
+    background: transparent;
+}
+
+.markdown-content a {
+    color: inherit;
+}
+
+.msg.user .bubble {
+    padding: 10px 20px;
+    background: #eee;
+    width: 50%;
+    margin-left: auto;
+    border: solid 1px #ddd;
+}
+
+.msg.tool .bubble {
+    font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
+    font-size: 60%;
+    max-height: 100px;
+    overflow: hidden;
+    cursor: pointer;
+}
+
+.chevron {
+    display: inline-block;
+    font-size: 10px;
+    margin-left: 6px;
+    transition: transform 0.2s;
+    vertical-align: middle;
+}
+
+.composer {
+    display: flex;
+    gap: 8px;
+    padding: 12px;
+    justify-content: center;
+}
+
+.composer textarea {
+    flex: 1;
+    resize: none;
+    height: 88px;
+    border: none;
+}
+
+.composer button {
+    align-self: center;
+}
+
+.composer .inner {
+    border: solid 1px #ddd;
+    border-radius: 20px;
+    padding: 10px;
+    display: flex;
+    width: 100%;
+}
+
+@keyframes spin { to { transform: rotate(360deg); } }
+.spinner {
+    width: 18px;
+    height: 18px;
+    border: 2px solid #aaa;
+    border-top-color: #333;
+    border-radius: 50%;
+    animation: spin 0.7s linear infinite;
+    display: inline-block;
+}
+
+.status {
+    font-size: 12px;
+    opacity: 0.7;
+}
+
+section > .row > label {
+    display: block;
+    font-size: 12px;
+    opacity: 0.75;
+    margin-bottom: 6px;
+    font-weight: bold;
+}
+
+section > .row > label .small {
+    font-weight: normal;
+    display: block;
+    font-size: 80%;
+}
+
+.side .row {
+    margin-bottom: 20px;
+}
+
+.provider-tabs {
+    display: flex;
+    flex-wrap: wrap;
+    gap: 6px;
+    background: #00000010;
+    padding: 6px 0 0 6px;
+}
+
+.provider-tab {
+    position: relative;
+    display: inline-flex;
+}
+
+.provider-tab input {
+    position: absolute;
+    opacity: 0;
+    pointer-events: none;
+}
+
+.provider-tab span {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  min-height: 38px;
+  padding: 8px;
+  border: 1px solid #d0d0d0;
+  border-radius: 2px 2px 0 0;
+  background: #e8e8e8;
+  color: #555;
+  cursor: pointer;
+  user-select: none;
+  transition: background 0.15s, border-color 0.15s, color 0.15s;
+  font-size: 75%;
+}
+
+.provider-tab input:checked + span {
+    background: #f9f9f9;
+    border-color: #999;
+    color: #111;
+    border-bottom: none;
+}
+
+.provider-tab input:focus-visible + span {
+    outline: 2px solid #666;
+    outline-offset: 2px;
+}
+
+.row button {
+    padding: 8px 10px;
+}
+
+
+hr {
+    border: dashed 1px #ddd;
+}
+
+.btn-row {
+    display: flex;
+    gap: 10px;
+}
+
+.btn-row > .btn,
+.btn-row > button.btn {
+    flex: 1 1 0;
+    min-width: 0;
+}
+
+.btn {
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    gap: 8px;
+    font-size: 14px;
+
+    padding: 10px 12px;
+    border-radius: 10px;
+    border: 1px solid #d0d0d0;
+    background: #eee;
+
+    cursor: pointer;
+    user-select: none;
+    text-decoration: none;
+}
+
+.btn:hover {
+    background: #ddd;
+}
+
+.btn:active {
+    transform: translateY(1px);
+}
+
+.btn-wide {
+    width: 100%;
+}
+
+.material-icons {
+    font-size: 18px;
+    line-height: 1;
+}
+
+.btn.disabled,
+.btn:disabled {
+    opacity: 0.55;
+    cursor: not-allowed;
+    pointer-events: none;
+}
+
+#input {
+    border: none;
+    outline: none;
+}
+
+#input:focus,
+#input:focus-visible {
+    outline: none;
+    box-shadow: none;
+}
+
+.code {
+    font-family: 'Courier New', Courier, monospace;
+    font-size: 90%;
+    background-color: #eee;
+    border: solid 1px #ddd;
+    padding: 2px;
+    display: inline-block;
+}
+
+header .row:nth-child(2) {
+    padding: 15px 0 0 0;
+}

src/ifcgeom/mapping/IfcPointByDistanceExpression.cpp

@@ -52,6 +52,15 @@ taxonomy::ptr mapping::map_impl(const IfcSchema::IfcPointByDistanceExpression* i
    if (inst->OffsetVertical().has_value()) {
        auto offset_vertical = inst->OffsetVertical().get() * length_unit_;
        o += offset_vertical * z;
+
+       auto tmp1 = (z * offset_vertical).eval();
+       auto tmp2 = (Eigen::Vector3d(0, 0, 1) * offset_vertical).eval();
+       auto tmp3 = (tmp1 - tmp2).eval();
+
+       std::ostringstream oss;
+       oss << "local z: " << z.x() << "," << z.y() << "," << z.z() << "; delta: " << tmp3.x() << "," << tmp3.y() << "," << tmp3.z();
+       auto osss = oss.str();
+       std::wcout << osss.c_str() << std::endl;
    }
 
    if (inst->OffsetLongitudinal().has_value()) {

src/ifcopenshell-python/ifcopenshell/draw.py

@@ -42,6 +42,7 @@ WHITE = numpy.array((1.0, 1.0, 1.0))
 
 DO_NOTHING = lambda *args: None
 
+ARRANGE_POLYGON_SETTINGS = W.arrange_polygon_settings() if hasattr(W, 'arrange_polygon_settings') else None
 
 @dataclass
 class draw_settings:
@@ -536,7 +537,7 @@ def main(
                     *(tup for i, tup in enumerate(zip(path_objects, section_polies, polies)) if has_relevant_zone(i))
                 )
 
-            arranged = W.arrange_polygons(polies)
+            arranged = W.arrange_polygons(*filter(None, (ARRANGE_POLYGON_SETTINGS,)), polies)
             svg_data_3 = W.polygons_to_svg(arranged, False)
             dom3 = parseString(svg_data_3)
             svg3 = dom3.childNodes[0]

src/ifcparse/IfcSchema.h

@@ -358,6 +358,7 @@ class IFC_PARSE_API entity : public declaration {
 
     const std::vector<const entity*>& subtypes() const { return subtypes_; }
     const std::vector<const attribute*>& attributes() const { return attributes_; }
+    const std::vector<const inverse_attribute*>& inverse_attributes() const { return inverse_attributes_; }
     const std::vector<bool>& derived() const { return derived_; }
 
     const std::vector<const attribute*> all_attributes() const {

src/ifcwrap/IfcGeomWrapper.i

@@ -1166,6 +1166,7 @@ ifcopenshell::geometry::taxonomy::item::ptr try_upcast(PyObject* obj0, swig_type
 %ignore svgfill::line_segments_to_polygons;
 %ignore svgfill::svg_to_polygons;
 %ignore svgfill::arrange_polygons;
+%ignore svgfill::abstract_arrangement;
 
 %template(svg_line_segments) std::vector<std::array<svgfill::point_2, 2>>;
 %template(svg_groups_of_line_segments) std::vector<std::vector<std::array<svgfill::point_2, 2>>>;
@@ -1287,9 +1288,9 @@ ifcopenshell::geometry::taxonomy::item::ptr try_upcast(PyObject* obj0, swig_type
 		}	
 	}
 
-	std::vector<svgfill::polygon_2> arrange_polygons(const std::vector<svgfill::polygon_2>& polygons) {
+	std::vector<svgfill::polygon_2> arrange_polygons(svgfill::arrange_polygon_settings settings, const std::vector<svgfill::polygon_2>& polygons) {
 		std::vector<svgfill::polygon_2> r;
-		if (svgfill::arrange_polygons(polygons, r)) {
+		if (svgfill::arrange_polygons(settings, polygons, r)) {
 			return r;
 		} else {
 			throw std::runtime_error("Failed to arrange polygons");

src/svgfill/src/svgfill.cpp

@@ -483,6 +483,18 @@ public:
 		return ps;
 	}
 
+	size_t delete_same_facet_edge_pairs() {
+        size_t n_deleted = 0;
+        for (auto it = arr.edges_begin(); it != arr.edges_end();) {
+            decltype(it) current = it++;
+            if (current->face() == current->twin()->face()) {
+                arr.remove_edge(current);
+                n_deleted++;
+			}
+        }
+        return n_deleted;
+	}
+
 	void merge(const std::vector<int>& edge_indices) {
 		if (edge_indices.empty()) {
 			return;

src/svgfill/src/svgfill.h

@@ -67,6 +67,7 @@ namespace svgfill {
 		virtual std::vector<int> get_face_pairs() = 0;
 		virtual size_t num_edges() = 0;
 		virtual size_t num_faces() = 0;
+        virtual size_t delete_same_facet_edge_pairs() = 0;
 	};
 
 	class SVGFILL_API context {
@@ -101,6 +102,7 @@ namespace svgfill {
 		void write(std::vector<std::vector<polygon_2>>&);
 		size_t num_edges() { return arr_->num_edges(); }
 		size_t num_faces() { return arr_->num_faces(); }
+        size_t delete_same_facet_edge_pairs() { return arr_->delete_same_facet_edge_pairs(); }
 
 		~context() {
 			delete arr_;
@@ -113,7 +115,22 @@ namespace svgfill {
 	SVGFILL_API std::string polygons_to_svg(const std::vector<std::vector<polygon_2>>& polygons, bool random_color=false);
 	SVGFILL_API std::string polygons_to_svg(const std::vector<polygon_2>& polygons, bool random_color = false);
 	SVGFILL_API bool svg_to_polygons(const std::string& data, const boost::optional<std::string>& class_name, std::vector<polygon_2>& polygons);
-	SVGFILL_API bool arrange_polygons(const std::vector<polygon_2>& polygons, std::vector<polygon_2>& arranged);
-}
+
+	struct SVGFILL_API arrange_polygon_settings {
+        bool debug_output = false;
+		// -1: compute from average edge length
+        double polygon_offset_distance = -1.;
+        // 0: use offset - union - negative offset to find the outer perimeter
+        // 1: radial walk along vertices; exact, but can only reuse vertices, not create new positions by means of intersections
+        int outer_perimiter_algo = 0;
+        // 0: outer perimiter and corridor center lines
+        // 1: input polygons, corridor center lines and segments connecting corridor center lines to input polygons
+        int topology_reconstruction_algo = 0;
+        bool perform_cleanup = true;
+        double subdivision_factor = 16.;
+    };
+
+	SVGFILL_API bool arrange_polygons(arrange_polygon_settings settings, const std::vector<polygon_2>& polygons, std::vector<polygon_2>& arranged);
+    }
 
 #endif