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 workflow-authoringgit 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/workflow-authoring)<a href="https://agentmods.dev/skills/letta-ai/letta-code/workflow-authoring"><img src="https://agentmods.dev/badge/skills/letta-ai/letta-code/workflow-authoring/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/workflow-authoring"><img src="https://agentmods.dev/badge/skills/letta-ai/letta-code/workflow-authoring.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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 | $0.00054 | $0.03637 |
| Opus 5.5 | $0.00022 | $0.01455 |
| Sonnet 5.5 | $0.00011 | $0.00727 |
| Haiku 4.5 | $0.00005 | $0.00364 |
Grade A, and why
workflow-authoring 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 3d 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 — 269 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Workflow authoring reference
A workflow structures work across many subagents — to be comprehensive (decompose and cover in parallel), to be confident (independent perspectives and adversarial checks before committing), or to take on scale one context can't hold (migrations, audits, broad sweeps). The script is where you encode that structure: what fans out, what verifies, what synthesizes.
When you do call the Workflow tool, the right move is often hybrid: scout
inline first (list the files, scope the diff, find the modules) to discover
the work-list, then call Workflow to pipeline over it, passing the list via
args. You don't need to know the shape before the task — only before the
orchestration step.
Common single-phase workflows you can chain across turns:
- Understand — parallel readers over relevant subsystems → structured map
- Design — judge panel of N independent approaches → scored synthesis
- Review — dimensions → find → adversarially verify
- Research — multi-modal sweep → deep-read → synthesize
- Migrate — discover sites → transform each → verify
For larger work, run several in sequence — read each result before deciding the next phase. You stay in the loop; each workflow is one well-scoped fan-out.
Every script must begin with export const meta = {...}:
export const meta = {
name: 'find-flaky-tests', // kebab-case, required
description: 'Find flaky tests and propose fixes', // required
phases: [ // one entry per phase() call
{ title: 'Scan', detail: 'grep test logs for retries' },
{ title: 'Fix', detail: 'one agent per flaky test' },
],
}
// script body starts here — use agent()/parallel()/pipeline()/phase()/log()
The meta object must be a PURE LITERAL — no variables, function calls,
spreads, or template interpolation.
What a subagent is
Every agent() call is one agent-free ephemeral conversation linked to the
invoking parent agent (is_subagent: true, named after the call's label).
It starts with nothing but its prompt: no memory, no conversation context, no
skills. Put ALL context a stage needs in the prompt — file paths, the rule it
should apply, what shape to return.
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.
- 3d ago Changed · +5 lines 997b68dd2bdc
- 7d ago Changed · +14 lines fb368dbaebf2
- 17d ago Changed · +31 lines 8ba263fec2f0
- 20d ago Changed · +1 lines 5952ed118c84
- 25d ago First seen · 218 lines · 54 tokens per session scan A 3ef90b6c00a3
workflow-authoring is a skill published in the GitHub repository letta-ai/letta-code (3,625 stars, last pushed today), licensed Apache-2.0. It adds 54 tokens to every session and 3,637 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 2026-09-21.
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