Initial: JSON extractor for messy LLM output

README.md

@@ -1,12 +1,31 @@
 ---
-title: Json Extractor
-emoji: 👁
+title: JSON Extractor
+emoji: 🎯
 colorFrom: yellow
-colorTo: red
+colorTo: green
 sdk: gradio
-sdk_version: 6.13.0
+sdk_version: "5.49.1"
+python_version: "3.12"
 app_file: app.py
 pinned: false
+license: mit
+short_description: "Pull clean JSON out of messy LLM text."
+tags:
+  - llm
+  - structured-output
+  - json
+  - parsing
+  - agentcast
 ---
 
-Check out the configuration reference at https://huggingface.co/docs/hub/spaces-config-reference
+# JSON Extractor
+
+Paste messy LLM output, get clean JSON. Powered by [`agentcast`](https://pypi.org/project/agentcast-py/).
+
+Handles fenced ` ```json ``` ` blocks, language-less fences, top-level arrays, inline JSON in prose, multi-line unfenced objects, and refusals (returns `null`).
+
+## Related
+
+- [`agentcast` on PyPI](https://pypi.org/project/agentcast-py/)
+- [The Agent Reliability Stack](https://mukundakatta.github.io/agent-stack/)
+- Companion dataset: [`llm-output-extraction-cases`](https://huggingface.co/datasets/mukunda1729/llm-output-extraction-cases)

app.py

@@ -0,0 +1,75 @@
+"""JSON extractor — pull JSON out of messy LLM text.
+
+Uses agentcast's tolerant extractor. Handles fenced blocks, inline JSON,
+trailing prose, and unfenced multi-line objects.
+"""
+
+import json
+import gradio as gr
+from agentcast import extract_json
+
+
+def extract(messy: str):
+    if not messy.strip():
+        return "_Paste some text to extract JSON from._", ""
+    extracted = extract_json(messy)
+    if extracted is None:
+        return "❌ **No JSON found.**\n\nTry: fenced ` ```json ... ``` `, inline `{...}`, or top-level array `[...]`.", ""
+    pretty = json.dumps(extracted, indent=2, ensure_ascii=False)
+    summary = f"✅ **Extracted** ({type(extracted).__name__}, {len(pretty)} chars pretty-printed)"
+    return summary, pretty
+
+
+with gr.Blocks(title="JSON Extractor — for messy LLM output", theme=gr.themes.Soft()) as demo:
+    gr.Markdown(
+        """
+        # JSON Extractor
+
+        Paste messy LLM output, get clean JSON. Powered by [`agentcast`](https://pypi.org/project/agentcast-py/).
+
+        Handles:
+        - Fenced ` ```json ... ``` ` blocks
+        - Fenced blocks with no language tag
+        - Top-level arrays `[...]`
+        - Inline JSON in prose
+        - Multi-line unfenced objects
+        - Refusals → returns `null`
+
+        Test cases drawn from [`llm-output-extraction-cases`](https://huggingface.co/datasets/mukunda1729/llm-output-extraction-cases) (20 real-world patterns).
+        """
+    )
+
+    with gr.Row():
+        with gr.Column():
+            txt = gr.Textbox(
+                value='Sure! Here is the answer:\n\n```json\n{"name": "Widget Pro", "price": 29.99}\n```\n\nLet me know if you need anything else!',
+                label="Messy LLM output",
+                lines=12,
+            )
+            btn = gr.Button("Extract", variant="primary")
+        with gr.Column():
+            summary_out = gr.Markdown()
+            json_out = gr.Code(language="json", label="Extracted JSON")
+    btn.click(extract, inputs=txt, outputs=[summary_out, json_out])
+
+    gr.Examples(
+        examples=[
+            ['Sure! Here is the answer:\n\n```json\n{"name": "Widget Pro", "price": 29.99}\n```\n\nLet me know!'],
+            ['{"answer": 42}'],
+            ['[{"k": 1}, {"k": 2}, {"k": 3}]'],
+            ['Final:\n\n{\n  "event": "login",\n  "ts": "2026-04-26T12:00:00Z"\n}\n\nDone.'],
+            ['I am sorry, I cannot answer that.'],
+        ],
+        inputs=txt,
+    )
+
+    gr.Markdown(
+        """
+        ---
+        Part of [The Agent Reliability Stack](https://mukundakatta.github.io/agent-stack/) · MIT licensed
+        """
+    )
+
+
+if __name__ == "__main__":
+    demo.launch(server_name="0.0.0.0", server_port=7860)

requirements.txt

@@ -0,0 +1,3 @@
+gradio==5.49.1
+huggingface_hub>=0.30,<1.0
+agentcast-py>=0.1.0