> ## Documentation Index > Fetch the complete documentation index at: https://docs.ctrlrun.dev/llms.txt > Use this file to discover all available pages before exploring further. # Try it in your browser > Run ctrlrun demo here, with no install: Python and the released ctrlrun wheel load into this tab and the five scenarios run in front of you. Press the button and `ctrlrun demo` runs in this tab: real Python, the released `ctrlrun` wheel from PyPI, and the same five scenarios you would get from `pip install ctrlrun && ctrlrun demo`. Nothing is sent anywhere. The demo is in-process, writes its evidence to an in-memory filesystem, and opens no socket. 
    Press the button. The first run downloads about 10 MB of Python; after that the browser caches it.
## What you should see All five scenarios run in the browser. This is the output from the verification run described below, with the generated ids masked: ```text theme={null} ctrlrun 0.5.0 on Python 3.14.2 CTRLRun demo — five ways an agent action goes wrong, and what stops it. Policy: refunds up to €1,000 are autonomous, up to €10,000 need a human, above that are denied. 1. Duplicate effect after a lost response refund €500 → remote commits → response lost → effect: AMBIGUOUS agent retries the same refund ✗ BLOCKED — effect may already have committed; blind retry refused remote refund calls: 1 only a human moves it on: ctrlrun resolve refund:txn_1 --committed|--failed 2. Approval mutation agent proposes refund €2,000 → human approves apr_… (bound to the action hash) agent executes refund €5,000 → ✗ BLOCKED — approved action ≠ requested action (mismatch) 3. Concurrent agents, same effect Agent A reserve refund:txn_123 → ACQUIRED → executes Agent B reserve refund:txn_123 → ✗ BLOCKED — already reserved (in_progress) 4. Approval replay approval apr_… used once → consumed same approval presented again → ✗ BLOCKED — single-use approval already consumed 5. Authority escalation human €100,000 delegable → finance agent €25,000 → support agent €2,000 support agent's grant: dlg_… support agent requests €50,000 → ✗ BLOCKED — outside the delegated grant (authority_constraint) remote refund calls: 0 finance agent tries to delegate €50,000 under its own €25,000 → refused (containment: constraints) support agent requests €1,500 → authority permits it, and the policy asks a human (apr_…) two axes, and an action needs both: the stricter of the pair wins ``` Scenario 1 is the one to read twice: **`remote refund calls: 1`**. The refund committed at the fake remote, the reply was lost, the agent retried, and the retry was refused. The customer was refunded once. ## What is running | | | | ------- | ------------------------------------------------------------------------------------------------------------------------- | | Runtime | [Pyodide](https://pyodide.org/) 314.0.6, CPython 3.14.2 compiled to WebAssembly, from the jsDelivr CDN | | Package | `ctrlrun`, installed from PyPI by micropip: the released version, the same wheel `pip install ctrlrun` gives you | | Storage | SQLite, bundled into Pyodide, writing to an in-memory filesystem that disappears when you close the tab | | Network | the CDN and PyPI, to load Python and the wheel. The demo itself opens no socket: its remote is a fake in the same process | The version line in the output is the released version, so it can be behind `main`. Everything else on this site describes the current release. ## Verified, and how to check The sequence this page runs was verified under Node against the same Pyodide build on **2026-09-06**: Pyodide 314.0.6, Python 3.14.2, SQLite 3.39.0, `ctrlrun` 0.5.0 from PyPI, all five scenarios. Two harnesses are committed, and you can run both: ```bash theme={null} npm install pyodide jsdom node docs/assets/verify-browser-demo.mjs # Python, the wheel, and the five scenarios node docs/assets/verify-browser-wiring.mjs # this page's button, against a real DOM ``` [`verify-browser-demo.mjs`](https://github.com/CTRLRun/ctrlrun/blob/main/docs/assets/verify-browser-demo.mjs) is the one that proved the demo runs. [`verify-browser-wiring.mjs`](https://github.com/CTRLRun/ctrlrun/blob/main/docs/assets/verify-browser-wiring.mjs) is the one that proves the button on this page gets wired: this site is a single-page application, and the first version of the script looked for its container before the page had rendered it, so the button did nothing. ## If it does not run here The page tells you what failed and gives you the command that always works: ```bash theme={null} pip install ctrlrun && ctrlrun demo ``` A browser can fail this for reasons that have nothing to do with CTRLRun: a blocked CDN, an extension that stops WebAssembly, a very old browser, or a tab with no memory to spare. That is this page failing, not the library. ## Next * [60-second quickstart](/get-started/quickstart): protect one function for real. * [Outcomes and AMBIGUOUS](/concepts/outcomes-and-ambiguous): what scenario 1 means. * [Get started](/get-started/install) · [Why](/why). ## Related topics - [CTRLRun](/index.md) - [OpenAI Agents SDK tool approval](/cookbook/openai-agents-tool-approval.md) - [Authority and delegation](/authority.md) - [An IAM agent that can grant read but never admin](/cookbook/iam-agent.md) - [Use the docs from your editor](/mcp/use-the-docs-from-your-editor.md)