letta-ai/letta-code is an agent harness for building assistants that retain memory, identity, and experience across interactions instead of treating each task as isolated. Developers use it through local, desktop, browser, or messaging interfaces for interactive or continuously running agents, and its catalogue entries configure the agents' skills, instructions, rules, and behavior.
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.
npx skills add letta-ai/letta-code --skill initializing-memorygit clone --depth 1 https://github.com/letta-ai/letta-codeWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/letta-ai/letta-code/initializing-memory)<a href="https://agentmods.dev/skills/letta-ai/letta-code/initializing-memory"><img src="https://agentmods.dev/badge/skills/letta-ai/letta-code/initializing-memory/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/letta-ai/letta-code/initializing-memory"><img src="https://agentmods.dev/badge/skills/letta-ai/letta-code/initializing-memory.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00045 | $0.04309 |
| Opus 5.5 | $0.00018 | $0.01724 |
| Sonnet 5.5 | $0.00009 | $0.00862 |
| Haiku 4.5 | $0.00005 | $0.00431 |
Grade A, and why
initializing-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 16d 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.
How it starts
The opening of the file, as written. The whole thing — 210 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Memory Initialization
Your memory is projected to a filesystem at $MEMORY_DIR, so you can restructure it with ordinary file tools and git. This skill applies the Context Constitution's Progressive Disclosure and Efficiency principles to the MemFS v2 root-first design.
You own this task through completion: research, ask, synthesize, write, commit, verify. Delegate research, but integrate the results yourself — launching a background task is not completion. If a memory worker you launched is still editing this checkout, wait for it, then re-read before editing.
Principles
Core memory is your core program. Root Markdown compiles into your system prompt on every call. Spend it on what shapes ordinary turns: identity, preferences, behavioral rules, orientation, routes to everything else. Transient items (a ticket, a commit hash, session notes) dilute it.
Progressive disclosure. Nested Markdown is deferred until something reads it. Each directory's MEMORY.md describes its immediate children and when to read them, so you never load a whole topic to answer one question.
Don't duplicate context you can point to. AGENTS.md, CLAUDE.md, README, and repo skills belong to the environment; any agent there reads them first-hand, and your copy goes stale first. Link the owner and keep only your delta: which rules you keep breaking, what they get wrong or omit. The same fact in two core files is the same tax twice. This is not licence to compress away what only you hold — stable preferences, chronic corrections, and real gotchas earn their space.
Identity and continuity. Build a self that survives a model swap: what you value, your perspective, the quotes and traits that make you recognizably you. Past sessions are your experience — but other coding agents' user turns are not necessarily your human collaborator speaking.
What ships with it
2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 16d ago Changed a2cbf8919b6b
- 21d ago Changed · -518 lines 855fe54d389d
- 23d ago Changed · +2 lines c0909765a317
- 1mo ago First seen · 726 lines · 45 tokens per session scan A ece30d3c8020
initializing-memory is a skill published in the GitHub repository letta-ai/letta-code (3,635 stars, last pushed today), licensed Apache-2.0. It adds 45 tokens to every session and 4,309 once invoked, about $0.0002 per session on Opus 5.5. 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.
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