`memory` Plugin

memory is the agent long-term memory plugin. It exposes memory capabilities to the agent while organizing durable knowledge as an LLM Wiki internally.

It provides:

memory wiki search
memory wiki reads
explicit facts, preferences, and decisions
session-to-wiki digest
wiki page revision with new evidence
memory system text

Main Shape

lifecycle
actions
system

Storage Shape

.downcity/memory/
  wiki/       # curated knowledge layer primarily read by agents
  sources/    # raw evidence from sessions and manual inputs

wiki/ is the main long-term memory surface. sources/ is evidence and rebuild material. Search defaults to the wiki layer; include sources only when evidence is needed.

Constructor Injection

LLM digest/revise capabilities are passed through the constructor:

import { MemoryPlugin } from "@downcity/plugins";

const memory = new MemoryPlugin({
  digest: async (input) => {
    return {
      pages: [
        {
          path: "project-decisions.md",
          title: "Project Decisions",
          content: "Compiled wiki markdown",
        },
      ],
      summary: "Updated project decisions.",
    };
  },
  revise: async (input) => {
    return {
      path: input.path,
      content: "Full revised wiki markdown",
    };
  },
});

If digest or revise is not provided, the plugin falls back to deterministic behavior: archive the source and append to wiki pages without calling a model.

How Users Use It

Use the downcity memory shortcut for normal local operation:

downcity memory status
downcity memory search "project decision" --max-results 5
downcity memory read .downcity/memory/wiki/project-decisions.md --from 1 --lines 20
downcity memory remember --content "Prefer constructor-based plugin config." --topic "plugin system"
downcity memory digest --session-id <sessionId> --max-messages 30
downcity memory revise .downcity/memory/wiki/plugin-system.md --instruction "Merge the latest constructor config decision"

SDK Action Use

await agent.plugins.runAction({
  plugin: "memory",
  action: "remember",
  payload: {
    content: "User preference: plugin config is passed through constructors.",
    topic: "plugin system",
  },
});

The action names are status, search, read, remember, digest, and revise.

Important Semantics

MemoryPlugin is LLM Wiki style memory, not a vector database.
wiki/ is the primary durable knowledge layer for agents.
sources/ is evidence and is excluded from search unless includeSources is set.
LLM capabilities are injected through the constructor, not read from project config files.
Memory enablement is separate from whether the plugin exists in code.

memory Plugin