Frequently Asked Questions

Q: Which LLMs are supported?

Glassbrain supports any LLM accessible via the OpenAI, Anthropic, Cohere, Google Gemini, or Mistral client libraries. It also integrates with orchestration frameworks like LangChain and LlamaIndex, and accepts traces from any OpenTelemetry-compatible source.

Q: How long is trace data retained?

Retention depends on your plan. Free accounts retain traces for 24 hours. Pro accounts retain traces for 30 days. Team accounts retain traces for 60 days. Business accounts retain traces for 90 days.

Q: Can I self-host Glassbrain?

Not at this time. Glassbrain is currently offered as a managed cloud service only. We are evaluating self-hosted and on-premises deployment options for enterprise customers. Contact us at enterprise@glassbrain.dev to express interest.

Q: Are there rate limits?

Yes. The Free plan allows up to 1,000 traces per month. Pro allows 50,000 traces per month. Team allows 200,000 traces per month. Business allows 500,000 traces per month. If you exceed your plan limits, the API will return a 429 error. Upgrading your plan takes effect immediately.

Q: How does replay work?

When you open a trace, Glassbrain reconstructs the full execution timeline from the captured data. The replay interface lets you step forward and backward through each node in the trace tree, inspecting the exact inputs, outputs, and metadata at each point. No additional recording or instrumentation is required beyond the standard SDK setup.

Q: What does Glassbrain cost?

Glassbrain offers four plans. Free includes 1,000 traces per month and 24-hour retention at no cost. Pro is $39 per month with 50,000 traces per month and 30-day retention. Team is $149 per month for 5 seats with 200,000 traces per month and 60-day retention. Business is $399 per month for 15 seats with 500,000 traces per month and 90-day retention. See the pricing page for full details.

Answers to the most common questions about Glassbrain. If you cannot find what you are looking for here, reach out to us at support@glassbrain.dev.

What is Glassbrain?

Glassbrain is a visual debugging engine for AI-powered applications. It captures every LLM call, tool invocation, and chain step as a structured trace, then lets you replay and inspect them in a rich visual interface. Instead of digging through logs to figure out why your AI gave a wrong answer, you can see the full execution path at a glance and pinpoint the exact step that went wrong.

Which LLMs are supported?

Glassbrain works with any LLM provider that you access through a supported client library. Currently supported providers include:

OpenAI (GPT-4o, GPT-4, GPT-3.5, o1, o3, and all other models)
Anthropic (Claude 4, Claude 3.5, Claude 3, and all other models)
Google Gemini
Cohere
Mistral

Glassbrain also integrates with orchestration frameworks like LangChain and LlamaIndex, and accepts traces from any OpenTelemetry-compatible source.

How long is trace data retained?

Retention depends on your plan:

Free - 24 hours
Pro - 30 days
Team - 60 days
Business - 90 days

Can I self-host Glassbrain?

Glassbrain is currently offered as a managed cloud service only. We are evaluating self-hosted and on-premises deployment options for enterprise customers with strict data residency requirements. If this is important to your organization, please contact us at enterprise@glassbrain.dev to discuss your needs.

Are there rate limits?

Yes. Each plan includes a monthly trace limit:

Free - 1,000 traces/month
Pro - 50,000 traces/month
Team - 200,000 traces/month
Business - 500,000 traces/month

If you exceed your plan limits, the API will return a 429 status code. Upgrading your plan takes effect immediately with no downtime.

How do I keep my API key secure?

Follow these best practices to keep your Glassbrain API key safe:

Store your API key in environment variables or a secrets manager - never hard-code it in source files
Add your .env file to .gitignore
Use separate API keys for development and production environments
Rotate keys periodically from your project settings - the old key remains valid for 5 minutes after rotation to allow graceful transition
Restrict API key permissions to only the actions your application needs

If you believe your key has been compromised, rotate it immediately from your project settings. The new key takes effect in under 10 seconds.

How does replay work?

When you open a trace in the Glassbrain dashboard, the replay interface reconstructs the full execution timeline from the captured data. You can:

Step forward and backward through each node in the trace tree
Inspect the exact inputs, outputs, and metadata at each step
Jump directly to any node by clicking it in the trace tree
Use keyboard shortcuts (arrow keys) for fast navigation

No additional recording or instrumentation is required beyond the standard SDK setup. The replay is fully deterministic and based on the data captured during the original execution. Learn more in the Time-Travel Replay guide.

What does Glassbrain cost?

Glassbrain offers four plans:

Free - $0/month. 1,000 traces/month, 24-hour retention, 1 project.
Pro - $39/month. 50,000 traces/month, 30-day retention, 5 projects, unlimited AI fix suggestions.
Team - $149/month. 200,000 traces/month, 60-day retention, 5 team members, 10 projects.
Business - $399/month. 500,000 traces/month, 90-day retention, 15 team members, unlimited projects, SSO, priority support.

All paid plans include a 14-day free trial. See the pricing page for full details.

How large is the SDK?

The JavaScript SDK is approximately 45 KB minified and gzipped, with zero runtime dependencies. The Python SDK is approximately 60 KB installed, also with zero required dependencies beyond the standard library. Both SDKs are designed to have negligible impact on your application's startup time and memory usage. The SDK sends traces asynchronously in the background and never blocks your application's main thread or event loop.

Is Glassbrain open source?

The Glassbrain SDKs for JavaScript and Python are open source under the MIT license. You can find them on GitHub:

glassbrain-dev/glassbrain-js - JavaScript / TypeScript SDK
glassbrain-dev/glassbrain-python - Python SDK

The Glassbrain dashboard, API server, and trace processing pipeline are proprietary. We welcome community contributions to the SDKs - see the contributing guide in each repository for details.