knowledge_forget

Remove outdated, incorrect, or irrelevant knowledge entries from the Prism MCP server to maintain a clean and relevant knowledge base. Delete entries by project, category, age, or perform a full reset.

Instructions

Selectively forget (delete) accumulated knowledge entries. Like a brain pruning bad memories — remove outdated, incorrect, or irrelevant session entries to keep the knowledge base clean and relevant.

Forget modes:

By project: Clear all knowledge for a specific project
By category: Remove entries matching a category (e.g. 'debugging')
By age: Forget entries older than N days
Full reset: Wipe everything (requires confirm_all=true)

⚠️ This permanently deletes ledger entries. Handoff state is preserved unless explicitly cleared.

Input Schema

TableJSON Schema

Name	Required	Description
`project`	No	Project to forget entries for. Required unless using confirm_all.
`category`	No	Optional: only forget entries in this category (e.g. 'debugging', 'resume').
`older_than_days`	No	Optional: only forget entries older than this many days.
`clear_handoff`	No	Also clear the handoff (live state) for this project. Default: false.
`confirm_all`	No	Set to true to confirm wiping ALL entries for the project (safety flag).
`dry_run`	No	If true, only count what would be deleted without actually deleting. Default: false.

Implementation Reference

src/tools/sessionMemoryHandlers.ts:592-672 (handler)

Handler for the 'knowledge_forget' tool, which prunes ledger entries and optionally clears project handoff data.

export async function knowledgeForgetHandler(args: unknown) {
  if (!isKnowledgeForgetArgs(args)) {
    throw new Error("Invalid arguments for knowledge_forget");
  }

  const {
    project,
    category,
    older_than_days,
    clear_handoff = false,
    confirm_all = false,
    dry_run = false,
  } = args;

  if (!project && !confirm_all) {
    return {
      content: [{
        type: "text",
        text: `⚠️ Safety check: You must specify a 'project' to forget, ` +
          `or set 'confirm_all: true' to wipe all entries.\n` +
          `This prevents accidental deletion of all knowledge.`,
      }],
      isError: true,
    };
  }

  console.error(`[knowledge_forget] ${dry_run ? "DRY RUN: " : ""}Forgetting: ` +
    `project=${project || "ALL"}, category=${category || "any"}, ` +
    `older_than=${older_than_days || "any"}d, clear_handoff=${clear_handoff}`);

  const storage = await getStorage();

  const ledgerParams: Record<string, string> = {};
  ledgerParams.user_id = `eq.${PRISM_USER_ID}`;
  if (project) {
    ledgerParams.project = `eq.${project}`;
  }
  if (category) {
    ledgerParams.keywords = `cs.{cat:${category}}`;
  }
  if (older_than_days) {
    const cutoffDate = new Date();
    cutoffDate.setDate(cutoffDate.getDate() - older_than_days);
    ledgerParams.created_at = `lt.${cutoffDate.toISOString()}`;
  }

  let ledgerCount = 0;
  let handoffCleared = false;

  if (dry_run) {
    const selectParams = { ...ledgerParams, select: "id" };
    const entries = await storage.getLedgerEntries(selectParams);
    ledgerCount = entries.length;
  } else {
    const result = await storage.deleteLedger(ledgerParams);
    ledgerCount = result.length;

    if (clear_handoff && project) {
      await storage.deleteHandoff(project, PRISM_USER_ID);
      handoffCleared = true;
    }
  }

  const action = dry_run ? "would be forgotten" : "forgotten";
  const emoji = dry_run ? "🔍" : "🧹";

  return {
    content: [{
      type: "text",
      text: `${emoji} ${ledgerCount} ledger entries ${action}` +
        (project ? ` for project "${project}"` : "") +
        (category ? ` in category "${category}"` : "") +
        (older_than_days ? ` older than ${older_than_days} days` : "") +
        `.\n` +
        (handoffCleared ? `🗑️ Handoff state also cleared for "${project}".\n` : "") +
        (dry_run ? `\n💡 This was a dry run — nothing was actually deleted. Remove dry_run to execute.` : "") +
        (!dry_run && ledgerCount > 0 ? `\n✅ Knowledge base pruned. Fresh start!` : ""),
    }],
    isError: false,
  };
}

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