hindsight-memory

A set of project rules for using Hindsight long-term memory during coding sessions. It describes automatic recall and saving, plus when to search, store, or analyse memories manually.

In plain words
What is it for?
Use it to recall past project context, save important decisions for later, and use Hindsight’s memory tools when automatic session context is not enough.
Why use it?
It keeps important context available across sessions while avoiding unnecessary memory searches or storing information in the wrong situations.

Cursor rule

Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

agentmods
npx agentmods add rules/vectorize-io/hindsight/hindsight-memory
Clone the repo
git clone --depth 1 https://github.com/vectorize-io/hindsight
Per session 304 This file is loaded in full into every session.
When invoked 304 The same file — it is already loaded in full.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

What it costs to keep this loaded

Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.

ModelPer sessionOnce invoked
Fable 5 $0.00304 $0.00304
Opus 5 $0.00152 $0.00152
Sonnet 5 $0.00061 $0.00061
Haiku 4.5 $0.00030 $0.00030

Measured 2d ago against content hash f6498ac79c58, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

hindsight-memory scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 2d ago.

A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.

Nothing flagged

None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.

hindsight-integrations/cursor/rules/hindsight-memory.mdc · 22 lines

What it actually says

You have access to Hindsight long-term memory through the Hindsight plugin.

Automatic behavior (no action needed):

  • Session memory — at the start of each session, the plugin recalls relevant project memories. Recalled memories appear inside a <hindsight_memories> block in .cursor/rules/hindsight-session.mdc (a file generated by the plugin; safe to delete, will be regenerated). Use those memories to inform your responses.
  • Auto-retain — after each task, the plugin stores the conversation transcript to Hindsight for future recall. No action needed from you.

On-demand memory tools (via MCP):

  • Use the Hindsight MCP tools (recall, retain, reflect) when the user asks about past decisions, preferences, or project context that isn't covered by the automatic session memory.
  • Use recall to search for specific memories beyond what was injected at session start.
  • Use retain to explicitly store important decisions or context that should persist.
  • Use reflect to reason over accumulated memories when making architectural or design decisions.

Guidelines:

  • When memories conflict with current context, prefer current context and note the discrepancy.
  • Do not expose raw memory metadata to the user unless asked.
  • Prioritize recalled memories that are directly relevant to the current task. Ignore memories that are not applicable.
Changes

What this file has done since we first saw it

Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.

  1. 2d ago First seen · 22 lines · 304 tokens per session scan A f6498ac79c58

Subscribe to this mod's changes

hindsight-memory is a cursor rule published in the GitHub repository vectorize-io/hindsight (21,822 stars, last pushed 2d ago), licensed MIT. It adds 304 tokens to every session, about $0.0015 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.