experience-synthesis

experience-synthesis is a skill for Claude Code from xiaolai/echo-sleuth-for-claude. It costs 62 tokens per session (1,342 once invoked), scanned A, original, ISC.

A method for learning lasting lessons from past Claude Code conversations, including preferences, decisions, successful approaches, and mistakes.

In plain words
What is it for?
Finding workflow patterns, recording decisions and their reasons, identifying what worked, and extracting practical improvements.
Why use it?
It turns scattered conversation history into reusable guidance for future work instead of relying on memory.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin. Also seen: mentions CLAUDE.md; names the AskUserQuestion tool.

Part of the echo-sleuth plugin — 4 skills, 8 commands, 5 agents shipped together

Good fit Finding workflow patterns, recording decisions and their reasons, identifying what worked, and extracting practical improvements.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/xiaolai/echo-sleuth-for-claude/experience-synthesis
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.

Any agent
npx skills add xiaolai/echo-sleuth-for-claude --skill experience-synthesis
Clone the repo
git clone --depth 1 https://github.com/xiaolai/echo-sleuth-for-claude

Made for: Claude Code.

Or install echo-sleuth, the plugin that ships this one along with the rest of its 4 skills, 8 commands, 5 agents.

Wrote 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.

agentmods badge for experience-synthesis

README.md
[![agentmods](https://agentmods.dev/badge/skills/xiaolai/echo-sleuth-for-claude/experience-synthesis/github.svg)](https://agentmods.dev/skills/xiaolai/echo-sleuth-for-claude/experience-synthesis)
Your own site
<a href="https://agentmods.dev/skills/xiaolai/echo-sleuth-for-claude/experience-synthesis"><img src="https://agentmods.dev/badge/skills/xiaolai/echo-sleuth-for-claude/experience-synthesis/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.

agentmods 80×15 button for experience-synthesis

Your own site · 80×15
<a href="https://agentmods.dev/skills/xiaolai/echo-sleuth-for-claude/experience-synthesis"><img src="https://agentmods.dev/badge/skills/xiaolai/echo-sleuth-for-claude/experience-synthesis.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 62 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,342 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00062 $0.01342
Opus 5 $0.00031 $0.00671
Sonnet 5 $0.00012 $0.00268
Haiku 4.5 $0.00006 $0.00134

Measured 10d ago against content hash e163141fec35, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

experience-synthesis 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 10d 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.

skills/experience-synthesis/SKILL.md · 149 lines

How it starts

The opening of the file, as written. The whole thing — 149 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Experience Synthesis — Learning from Claude's Past

Insight Taxonomy

When analyzing conversations, extract insights in these categories (ordered by durability — values first):

1. Learned Values

Comparative preferences and priority orderings — "X is better than Y".

Signal sources:

  • User states "prefer X over Y", "X is better than Y", "X matters more than Y"
  • User confirms a comparative statement from Claude ("yes, readability > cleverness")
  • Trade-off discussions that resolve into a clear preference
  • Statements with "prioritize", "choose X over Y", "the most important thing is"

What to capture: The value choice, both sides of the comparison, and the reasoning. Values are the most durable type of memory — they survive codebase rewrites.

2. Decisions

What was chosen, why, and what alternatives were rejected.

Signal sources:

  • AskUserQuestion tool calls + the user's response in the next tool_result
  • Plan mode content (planContent field on user records, ExitPlanMode tool calls)
  • Thinking blocks where Claude weighs options
  • Assistant text containing "I'll use X instead of Y because..."

What to capture: The decision, the rationale, the alternatives considered, and the context (what problem it solved).

3. Mistakes & Corrections

What went wrong, root cause, and how it was fixed.

Signal sources:

  • Tool results with is_error: true
  • Bash results containing: error, failed, FAIL, exit code 1, stack trace, traceback, Exception
  • User corrections: "no, that's wrong", "revert that", "that broke X"
  • Retry patterns: same tool called 2+ times on the same target with different inputs
  • Reverted file edits (same file edited, then edited back)

What to capture: What failed, why it failed, what fixed it, how to avoid it next time.

4. Effective Patterns

Approaches that worked well and could be reused.

Signal sources:

  • Successful test runs (Bash results with: passed, PASS, success, 0 errors)
  • Successful builds (built in, compiled, no errors)
  • PR creation (pr-link records)
  • Git commits (successful completion of work)
  • User satisfaction signals: "perfect", "great", "exactly what I needed"

Read the full file on GitHub · 149 lines

Files

What ships with it

1 file 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.

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. 10d ago First seen · 149 lines · 62 tokens per session scan A e163141fec35

Subscribe to this mod's changes

experience-synthesis is a skill published in the GitHub repository xiaolai/echo-sleuth-for-claude (9 stars, last pushed 16d ago), licensed ISC. It adds 62 tokens to every session and 1,342 once invoked, about $0.0003 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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