RxInfer MCP
RxInfer MCP powers RxInfer Pro's developer tooling. It brings Bayesian decision support to your assistants and scores LLM responses with transparent uncertainty. This guide covers how to deploy it, plug it into different clients, and operate it safely.
Built on RxInfer
RxInfer MCP is built upon the RxInfer.jl framework—a powerful Julia package for reactive Bayesian inference. Our MCP server exposes this capability through a developer-friendly interface for AI assistants and LLM workflows.
RxInfer tools
Unified suite spanning contextual decisions and LLM response evaluation.
Train a Bayesian action-reward model from historical CSV data.
Provide context, actions, and rewards; receive a session ID that anchors later predictions.
Score every candidate action for a new context using a trained session.
Returns expected reward plus uncertainty bands so assistants can choose with confidence.
Incrementally refine an existing session with fresh observations.
Keeps the Bayesian posterior up to date without retraining from scratch.
Audit an LLM answer for truthfulness and reliability with uncertainty quantification.
Outputs class probabilities, confidence intervals, and representative posterior samples.
What you get
- Contextual decision engine: Generate probabilistic recommendations for the actions you can take, complete with confidence intervals and downside risk.
- LLM response evaluator: Score LLM answers for truthfulness and reliability, returning probability distributions rather than brittle single numbers.
Installation
RxInfer MCP is reachable at https://rxinfer-mcp-775335415984.europe-west4.run.app/mcp. The sections below cover the platforms that support remote MCP connectors today.
Claude.ai (web)
Available for Pro, Max, Team, and Enterprise plans.
- Open Settings → Connectors.
- Click Add custom connector.
- Paste the RxInfer MCP URL.
- Finish the flow and enable the connector via the Search & tools toggle inside a chat.
Team and Enterprise organizations need an administrator to enable the connector first under Admin settings → Connectors. Individual users can then authenticate and toggle it on for themselves.
Claude Desktop
- Open Claude Desktop → Settings.
- Navigate to Developer → Model Context Protocol.
- Click Edit Config and add:
{
"mcpServers": {
"rxinfer": {
"url": "https://rxinfer-mcp-775335415984.europe-west4.run.app/mcp"
}
}
}
- Restart the desktop client to load the configuration.
Cursor
- Open Cursor Settings (
⌘+,on macOS,Ctrl+,on Windows/Linux). - Search for Model Context Protocol.
- Enable MCP and add the RxInfer MCP URL.
- Restart Cursor.
ChatGPT (custom GPTs)
Official support is coming to the GPT Store. In the meantime you can wire RxInfer MCP via Actions:
- Create or edit a GPT.
- Go to Configure → Actions → Create new action.
- Import from URL using the RxInfer MCP endpoint.
- Test and publish your GPT.
Le Chat (Mistral)
Le Chat advertises MCP compatibility and we can establish a connection, but the product currently fails to pass the correct tool arguments. If you find a reliable workaround, please let us know or share it on the community Discord.
Contextual decisions
Use this workflow when you need action recommendations with quantified uncertainty.
You: “We’ve got churn history in CSV form. Learn the best retention move.”
Assistant: “Loading the data and choosing the right contextual decisions tool…” → calls
learn_contextual_decisions→ “Model trained; sessionsess_42is ready.”You: “For this at-risk customer, what should we do?”
Assistant: “Let me use the trained session…” → calls
predict_contextual_action(sess_42, context)→ “Recommendoffer_credit. Expected uplift 0.62 with ±0.12 uncertainty.update_contextual_modelis available if new outcomes arrive.”
Prepare the dataset
- Provide historical decisions with outcomes in CSV (or convertible) form.
- Include columns for relevant context features, the action taken, and the observed outcome.
customer_age,usage_days,support_tickets,action,revenue
25,30,2,standard,145.50
45,5,8,premium_support,89.20
35,90,1,discount,203.75
55,15,3,standard,112.00
Smaller datasets (≤ 20 rows) can be pasted directly into a chat. For larger files, upload them to any publicly accessible location—GitHub Gist, tmpfiles.org, Dropbox, Google Drive—and share the link with your assistant.
Ask for recommendations
-
Share the dataset with your assistant.
-
Request probabilistic predictions. Example prompt:
“Given this history, what action should we take for a 35-year-old customer with 60 days usage and 2 support tickets? Include confidence intervals and explain the risk trade-offs.”
Interpret the output
You’ll receive:
- Expected outcomes for each candidate action with confidence bounds.
- Probability of one action outperforming another.
- Downside-risk commentary (e.g. worst-case outcomes, high-variance warning).
- A recommendation that explicitly incorporates uncertainty, not just averages.
Example conversations
- Churn prevention strategy (Claude share)
- Lead qualification & prioritisation (Claude share)
- Onboarding new customers:
LLM response evaluation
evaluate_llm_response grades model answers while exposing how certain the score is.
Parameters
question(string, required) — The original question.answer(string, required) — The model response to evaluate.mode(optional) — One ofquick,standard, orthorough. Defaults tostandard.
Modes at a glance
Best for
Rapid triage, bulk evaluation runs
Characteristics
Lowest compute cost, higher uncertainty
Best for
Everyday usage
Characteristics
Balanced speed and confidence (default)
Best for
Safety-critical or high-stakes reviews
Characteristics
Slowest runtime, tightest uncertainty intervals
Example interaction
You: “Did the assistant just hallucinate? Please review this answer: ‘Customer missed three invoices and dropped usage—flag churn risk?’”
Assistant: “Checking which tool applies…” → selects
evaluate_llm_response→ “Calling inthoroughmode.”Tool response:
correct(0.72 ± 0.09). Alternatives:incorrect0.11,unclear0.09, others <0.05.
Interpreting the results
The evaluator returns:
- A truthfulness / reliability rating.
- Probability distributions showing alternative scores.
- Standard deviations and confidence intervals, signalling how trustworthy the evaluation itself is.
Why uncertainty matters
Low uncertainty means the evaluator is confident in the score. High uncertainty flags ambiguous prompts,
nuanced answers, or limited training data—treat those responses as hypotheses, not facts.
Platform support
Claude.ai (web)
Available today for Pro, Max, Team, Enterprise plans
Claude Desktop
Requires manual edit to the MCP config file
Cursor
Enable MCP and add the server URL in settings
ChatGPT Actions
Works via custom GPT actions until GPT Store release
Le Chat
Connector authenticates but tool arguments are not forwarded correctly
Data guidelines
- For reliable results, aim for
50–100observations per action with balanced coverage. - The system can operate on as few as
20–30observations; uncertainty intervals will simply widen.
Security
- RxInfer MCP processes data in-memory only; no persistent storage is kept.
- Prefer anonymised identifiers and aggregated metrics whenever possible.
- Use temporary file links that expire after upload, especially for customer-level datasets.
- For enterprise deployments, we support private hosting with full data sovereignty—get in touch via contact.
Data privacy
RxInfer Pro operates on customer-provided data. Review how we handle submissions in our Terms of Agreement and ensure your own data policies allow sharing before uploading sensitive context.
Integrations
Integrations
Connect RxInfer MCP outputs with the tools your GTM teams already use.
Support
- Join the Lazy Dynamics Discord to collaborate with other builders.
- Submit questions, feedback, or deployment requests via contact.