retrospective

A command that reads recorded development mistake signals and turns recurring patterns into new gotcha rules. The signals can include reverted changes and test, lint, or type-check failures.

In plain words
What is it for?
Use it to inspect .claude/signals.jsonl, group failures by type, identify root causes from their details, and update gotchas.md with rules to avoid them.
Why use it?
It helps a project learn from repeated mistakes instead of treating each failure as an isolated event. When there are no recorded signals, it reports that plainly.

Command for Claude Code

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 commands/codeverbojan/claude-code-kickstart/retrospective
Clone the repo
git clone --depth 1 https://github.com/codeverbojan/claude-code-kickstart

Made for: Claude Code.

Per session 16 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 693 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 $0.00016 $0.00693
Opus 5 $0.00008 $0.00347
Sonnet 5 $0.00003 $0.00139
Haiku 4.5 $0.00002 $0.00069

Measured 2d ago against content hash e6fb978befd2, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

retrospective 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.

.claude/commands/retrospective.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Retrospective — Learn From Mistakes

Analyze .claude/signals.jsonl and generate new rules for gotchas.md.

1. Read Signals

Read .claude/signals.jsonl. Each line is a JSON object with:

  • timestamp: when the signal was captured
  • type: revert, test_failure, lint_failure, typecheck_failure
  • detail: human-readable description
  • command: the command that triggered the signal (secrets redacted)
  • snippet (optional): first 500 chars of failure output — use this for root cause analysis

If the file doesn't exist or is empty, report "No signals captured yet. Work on the project and mistakes will be automatically detected."

2. Group and Analyze

Group signals by type and look for patterns:

  • Repeated reverts on the same file → something about that file's patterns isn't understood
  • Repeated test failures → a testing pattern or convention is being missed
  • Repeated lint failures → a linting rule keeps being violated
  • Repeated typecheck failures → a type pattern isn't being followed

For each group, use the snippet field (when available) to identify the ROOT CAUSE pattern. "Tests failed 5 times" is a symptom. "Form validation was missing in 3 of 5 failures" is a pattern. If no snippet is available, group by command pattern and flag which files/commands repeatedly trigger failures.

3. Read Existing Gotchas

Read gotchas.md to check what rules already exist. Do NOT create duplicate rules. If an existing rule covers the pattern, skip it.

4. Generate New Rules

For each new pattern found, write a gotcha rule. Format:

N. [CATEGORY] Rule text — learned from [X signals over Y days]

Categories: [REVERT], [TEST], [LINT], [TYPECHECK]

Rules should be:

  • Actionable — tell Claude what TO DO, not just what went wrong
  • Specific — reference actual file patterns, commands, or conventions
  • Preventive — address the root cause, not the symptom

5. Append to gotchas.md

Append new rules under a ## Auto-generated section at the end of gotchas.md. If this section doesn't exist, create it. Find the highest existing rule number in the file (manual or auto-generated) and continue from there. Never overwrite or reorder existing rules.

Read the full file on GitHub · 80 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 · 80 lines · 16 tokens per session scan A e6fb978befd2

Subscribe to this mod's changes

retrospective is a command published in the GitHub repository codeverbojan/claude-code-kickstart (2 stars, last pushed 4mo ago), licensed MIT. It adds 16 tokens to every session and 693 once invoked, about $0.0001 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.