latestMarkerIsActive Function in i-have-adhd: Purpose and Cross-Runtime Significance

The latestMarkerIsActive function determines whether a custom feature marker is currently enabled or disabled by scanning context messages and returning the state of the most recent matching marker.

This utility enables runtime-agnostic feature toggling in the ayghri/i-have-adhd repository, allowing the library to adapt its behavior across diverse AI runtimes without hardcoding assumptions about any single platform's API.

Where latestMarkerIsActive Is Defined

The latestMarkerIsActive function lives in [extensions/context-compat.ts](https://github.com/ayghri/i-have-adhd/blob/main/extensions/context-compat.ts#L41-L61) alongside its companion helper contextMessages. Together these utilities form the compatibility layer that abstracts away runtime differences.

How latestMarkerIsActive Works

The function implements a state-tracking scan with four sequential steps:

1. Iterate through all messages — processes the array in order from first to last
2. Filter to custom markers — only examines messages where role === "custom" and type === "custom_message"
3. Track the latest state — updates an active boolean based on marker matches:
   • customType === activeType → active = true
   • customType === disabledType → active = false
4. Return final state — the last matching marker wins, giving the latest state

This last-write-wins semantics ensures user preference changes in conversation history are respected immediately.

Code Example: Basic Usage

import { latestMarkerIsActive } from "./extensions/context-compat";

const messages = [
  { role: "custom", type: "custom_message", customType: "adhd_enabled" },
  { role: "assistant", type: "text", content: "Hello!" },
  { role: "custom", type: "custom_message", customType: "adhd_disabled" },
];

const adhdIsOn = latestMarkerIsActive(
  messages,
  "adhd_enabled",   // activeType
  "adhd_disabled",  // disabledType
);

console.log(adhdIsOn); // → false (later disabled marker wins)

Architectural Significance of latestMarkerIsActive

Runtime-Agnostic Feature Toggling

Modern AI runtimes (Claude, Codex, Pi, OMP, etc.) expose session-manager APIs with varying context message formats. The latestMarkerIsActive abstraction lets the library detect feature states without runtime-specific code, scanning standardized message structures instead.

Graceful Degradation

When runtimes change APIs or fail to provide context, surrounding code falls back to a no-marker state. This prevents crashes and maintains stability across version migrations.

User-Controlled Preferences

End-users embed markers like adhd_enabled or adhd_disabled directly in conversations. The engine respects these preferences automatically without external configuration.

Where latestMarkerIsActive Is Used

Location	Purpose
[scripts/check_context_compat.ts](https://github.com/ayghri/i-have-adhd/blob/main/scripts/check_context_compat.ts)	Guards compatibility checks; aborts when a marker indicates intentional disable
[extensions/i-have-adhd.ts](https://github.com/ayghri/i-have-adhd/blob/main/extensions/i-have-adhd.ts)	Decides whether to inject ADHD-friendly response rules into the session

Integration Example: Compatibility Check Guard

import { contextMessages, latestMarkerIsActive } from "./extensions/context-compat";

function shouldRunCompatibilityCheck(sessionManager: unknown): boolean {
  const msgs = contextMessages(sessionManager);
  
  // Skip check if user explicitly disabled it
  if (!latestMarkerIsActive(msgs, "compat_check_enabled", "compat_check_disabled")) {
    return false;
  }
  
  return true; // proceed with check
}

Integration Example: ADHD Skill Injection

// extensions/i-have-adhd.ts
export function maybeInjectSkill(sessionManager: unknown): void {
  const msgs = contextMessages(sessionManager);
  
  if (latestMarkerIsActive(msgs, "adhd_enabled", "adhd_disabled")) {
    // Inject ADHD-friendly formatting: structured lists,
    // clear headings, progress indicators, etc.
  }
}

Key Files for latestMarkerIsActive

• [extensions/context-compat.ts](https://github.com/ayghri/i-have-adhd/blob/main/extensions/context-compat.ts) — core implementation and contextMessages helper
• [scripts/check_context_compat.ts](https://github.com/ayghri/i-have-adhd/blob/main/scripts/check_context_compat.ts) — real-world usage pattern with early-exit logic
• [extensions/i-have-adhd.ts](https://github.com/ayghri/i-have-adhd/blob/main/extensions/i-have-adhd.ts) — connection between marker logic and main feature

Summary

• latestMarkerIsActive provides single-source-of-truth state detection for custom features across the entire codebase
• Uses last-write-wins semantics on context message arrays to respect the most recent user preference
• Enables cross-runtime compatibility by abstracting over platform-specific session APIs
• Powers user-controlled toggles embedded directly in conversation context
• Guards critical code paths in compatibility checks and skill injection decisions

Frequently Asked Questions

What happens if no matching markers are found?

The function returns false by default. The active variable initializes to false and only flips to true when an explicit activeType marker appears.

Why compare both activeType and disabledType instead of just checking presence?

Explicit paired markers prevent ambiguity. A user might enable a feature early in conversation then disable it later—tracking both types ensures the latest intentional state wins regardless of marker order complexity.

Can this pattern work with runtimes that don't use context messages?

Yes. The contextMessages helper in the same file normalizes access patterns. For runtimes without native context support, the helper returns an empty array, causing latestMarkerIsActive to return false and trigger graceful fallback behavior.

How does this differ from simple environment variable configuration?

Environment variables are static per process. Context message markers are dynamic within a single session, allowing real-time toggling without restarts and per-conversation customization rather than global settings.

{
  "mcpServers": {
    "instagit": {
      "command": "npx",
      "args": ["-y", "instagit@latest"]
    }
  }
}