ReSim is now SignalFlag
On Monday, September 21, 2026, ReSim takes a new name: SignalFlag. It is the same product, the same team, and the same account you already have. This page lists exactly what changes for you and, more importantly, what does not.
Short version
Every URL, command, package, and credential you use today keeps working, and you do not need to change any of them. Two things are worth checking. If you filter inbound mail by sender domain, add signalflag.ai alongside resim.ai. If your network allowlists outbound domains and your team will use the new address, add app.signalflag.ai.
What changes
- Web app address. The app is also served at app.signalflag.ai. Your existing bookmark to app.resim.ai keeps working and shows the same app. Neither address redirects to the other, so links you have already shared, in tickets, chat, or CI output, stay valid.
- Name and logo. Starting the week of September 21, the app takes on the SignalFlag name, logo, and colors. Until that update lands you will still see ReSim branding, including at
app.signalflag.ai. - Website. Our website is signalflag.ai.
- Email from people on the team. Mail written by SignalFlag staff will start coming from
@signalflag.aiaddresses. Automated mail from the platform, such as organization invitations, keeps coming fromno-reply@resim.aifor now (see the note below). If you filter inbound mail by sender domain, allowsignalflag.aialongsideresim.ai.
Where you will still see the ReSim name for a while
- The sign-in page. Signing in still goes through our identity provider at
resim.us.auth0.com. That page still shows the ReSim logo and says Log in to ReSim to continue to app.resim.ai, even when you started fromapp.signalflag.ai. That is expected, and after you sign in you return to the address you started from. - Organization invitations. These still arrive from
ReSim <no-reply@resim.ai>, mention ReSim in the subject and body, and link toapp.resim.ai. They are legitimate. We will update them later in the transition. - Command and package names. The
resimCLI and theresim-*Python packages keep working under their current names. SignalFlag-named equivalents are planned; see What comes next. - These docs. They still say ReSim in most places and are being updated. Page URLs do not change.
If your network restricts outbound domains
app.resim.ai continues to work, so nothing needs to change. Allow app.signalflag.ai only if you want to use the new address. From either address, the app still calls api.resim.ai, bff.resim.ai, and resim.us.auth0.com, which you already allow.
What does not change
Everything below stays exactly as it is today. No configuration change is required on your side.
Your account and data
- Your organization, users, projects, systems, experiences, builds, batches, metrics, reports, and permissions are untouched.
- Log in the same way you do today, whether with your email and password or with Google or GitHub sign-in. Both addresses use the same sign-in.
- Pricing, contracts, and support contacts are unchanged.
Integrations and developer tools
| Component | Unchanged |
|---|---|
| REST API | https://api.resim.ai, including the OpenAPI spec served there |
| MCP server | https://bff.resim.ai/mcp |
| CLI | The resim command from github.com/resim-ai/api-client, the RESIM_* environment variables, and the ~/.resim/resim.yaml config file |
| Python packages | resim-sdk and resim-open-core on PyPI, the resim.* imports, and your metrics config files |
| HiL Agent | The agent binary from github.com/resim-ai/agent |
| GitHub Action | resim-ai/action |
| IDE extension | The resim-ai.resim extension for VS Code and Cursor |
| Source code | github.com/resim-ai |
| Documentation | docs.resim.ai, including llms.txt and the raw markdown URLs |
| Status page | status.resim.ai |
| Cloud access | Your organization's resim-customer-... IAM role and any CI credentials we have issued to you |
What comes next
We are changing the customer-facing name first. Every existing hostname, package name, and command name keeps working. Where we add SignalFlag-named equivalents, the resim ones stay alongside them. Over the coming weeks:
- Documentation. These docs are being updated to say SignalFlag and will also be available at
docs.signalflag.ai. They stay atdocs.resim.ai, so page URLs and existing links keep working. - CLI. The
resimcommand keeps working, so existing scripts and CI pipelines need no changes. We plan to also publish the CLI under thesignalflagname. When we do, we will post the install instructions here, andresimwill keep working alongside it. - Python packages.
resim-sdkandresim-open-corekeep working and remain maintained, so keep installing them. Version 1.6.0 and later already installsignalflag-demoas an alias forresim-demo. We plan to also publish SignalFlag-named packages on PyPI and will list them here when they exist. - GitHub. Our repositories, release downloads, and the GitHub Action stay under
github.com/resim-ai. If we move them, we will announce it in advance. - API and backend hostnames.
api.resim.aiandbff.resim.aistay as they are. There is noapi.signalflag.aiorbff.signalflag.ai, so keep theresim.aihostnames in API URLs, MCP configuration, and CI. If these hostnames change in the future, we will announce it in advance.
Why the new name?
When we launched, the platform orchestrated simulation, and ReSim made sense. Very quickly our customers asked for more: the same evaluations on hardware tests, on experiments run locally, and on production data. The platform has grown into a general set of tools that teams use to gain signal on the performance of their robots and to flag issues at the earliest opportunity.
We are not pivoting. Every current capability remains under active development, and the name change coincides with new features that build on the same infrastructure.
Questions?
Reach out to your usual SignalFlag contact, or email info@resim.ai.