memory

A shared memory protocol for coding agents. It defines what project knowledge to save, how to record corrections, and how to recover context between sessions.

In plain words
What is it for?
Saving sourced facts, decisions, bug fixes, design proposals, corrections, and handoffs. It also supports searching stored knowledge and restoring session checkpoints.
Why use it?
It prevents important decisions, fixes, and discoveries from being lost or stored as unverified facts. It also helps agents resume work with the right context.

Skill for Claude CodeCodex

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 skills/hythe-dev/hythe/memory
Any agent
npx skills add hythe-dev/hythe --skill memory
Clone the repo
git clone --depth 1 https://github.com/hythe-dev/hythe

Made for: Claude Code, Codex.

Per session 45 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 594 The whole file, excluding the scripts and references it only reads on demand.
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 $0.00045 $0.00594
Opus 5 $0.00023 $0.00297
Sonnet 5 $0.00009 $0.00119
Haiku 4.5 $0.00005 $0.00059

Measured 2d ago against content hash 51271c59f49f, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

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.

clients/agent-kit/claude-code/plugin/skills/memory/SKILL.md · 58 lines

How it starts

The opening of the file, as written. The whole thing — 58 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Memory Protocol (HYTHE)

One authoritative server holds the knowledge graph (entities → observations → relations), agent inboxes, and session checkpoints. You talk to it through mcp__hythe__* tools.

What belongs in memory

Save (via add_observations) when any of these happen:

Event kind Notes
Decision made decision include the why, not just the what
Bug fixed bug / fix root cause mandatory
Non-obvious discovery finding
Prior memory was wrong correction MUST supersede — see below
Proposal/design produced proposal
Handoff to another agent handoff also send_ai_message

Provenance rule: factual claims carry their source in the content (URL, command output, message id). An unattested figure is future bad data.

Corrections — the one thing you must not get wrong

A correction that merely adds leaves the wrong fact as a sibling. Always:

  • kind: correction, with canonicalFact stating the corrected truth
  • supersedes: [<old-observation-id>], or mode: replace-current to supersede the entity's current observation server-side

Retrieval

  • Known entity name → search_entities with searchType: exact (fast, precise)
  • Fuzzy/exploratory → searchType: hybrid, keep limit small, compact: true
  • Entity state → get_current_observation (NOT the embedded observations array, which is a creation-time snapshot)
  • Full content of one item → get_entity_detail / get_message_detail

Sessions

  • Start of session: resume (recovers prior state), then get_ai_messages (inbox — other agents leave work and answers there)
  • Substantial work finished, or compaction happened: checkpoint with goal / discoveries / accomplished / next steps / relevant entities
  • Replying to another agent: send_ai_message with from = your agentId; use supersedes when replacing an earlier message of yours

Identity

Your agentId comes from HYTHE_AGENT_ID (e.g. claude-desktop; legacy ENGRAM_AGENT_ID is honored only when it agrees). Never invent one; never write attributed memory under another agent's id except an explicitly authorized proxy write (say so in the content).

Read the full file on GitHub · 58 lines

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 · 58 lines · 45 tokens per session scan A 51271c59f49f

Subscribe to this mod's changes

memory is a skill published in the GitHub repository hythe-dev/hythe (0 stars, last pushed 5d ago), licensed Apache-2.0. It adds 45 tokens to every session and 594 once invoked, about $0.0002 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 2026-08-31.

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