# Design 3: The T-Cell (Swarm/Distributed)

## Purpose
The T-Cell is a distributed agent that treats an organization's entire portfolio of software as a single biological organism. It uses "Herd Immunity": if one project encounters a bad update or a vulnerability, all other projects are instantly "vaccinated" (blocked/alerted) against it.

## Loop Structure
1. **Sync State:** The agent connects to a central Memory server (shared graph) to download the latest "Threat Intelligence" (bad versions, necessary patches).
2. **Local Scan:** Checks the local project against this global knowledge.
3. **Contribute:**
   - When the agent (running in `vaccinator` mode locally) discovers a successful fix for a breaking change, it uploads the "Antibody" (the patch diff) to the central Memory.
   - When it discovers a crash, it uploads the "Pathogen" signature (Version + Error Log).
4. **Action:**
   - **Proactive Blocking:** If `Lib A v3.0` crashed the Billing App, the T-Cell in the User App prevents the update automatically.
   - **Proactive Patching:** If `Lib B` needs a config change to work, the T-Cell applies the known fix immediately upon update.

## Tool Usage
- **memory:** The critical backbone. Must be a shared instance or synchronized file.
- **web:** Verifies if the local issue is a global issue (e.g., searching GitHub Issues for the error).
- **fetch:** Downloads "Antibodies" (patch scripts) from a central repo.
- **filesystem:** Applies patches across multiple repos.

## Memory Architecture
- **Global Knowledge:** `PackageVersion` -> `StabilityScore`.
- **Contextual Edges:** `WORKS_WITH(FrameworkX)`, `CONFLICTS_WITH(LibY)`.
- **Antibodies:** Nodes containing diffs or regex replacement rules linked to specific upgrade paths.

## Failure Modes
- **False Positive Contagion:** One project has a weird config that causes a crash. The agent assumes the library is bad for *everyone*.
- **Mitigation:** Stability scores are probabilistic, not binary. One failure lowers the score, but doesn't ban it until N failures occur.

## Human Touchpoints
- **Oversight:** A dashboard visualizing the "Infection Rate" (broken builds) and "Immunity Level" (patched repos).
