deja-history

deja-history is a skill for Claude Code from vshulcz/deja-vu. It costs 47 tokens per session (647 once invoked), scanned A, original, MIT.

A search tool for the user’s previous AI coding sessions. It looks through local session history for earlier fixes, decisions, errors, and discussions.

In plain words
What is it for?
Use it to find earlier work by error message, function name, file path, or topic, and to check past sessions before debugging or editing.
Why use it?
It helps recover context instead of repeating an investigation or making a decision that was already settled. It is for personal session history, not general web or library research.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the deja-vu plugin — 1 skill, 1 command shipped together

Good fit Use it to find earlier work by error message, function name, file path, or topic, and to check past sessions before debugging or editing.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/vshulcz/deja-vu/deja-history
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 vshulcz/deja-vu --skill deja-history
Clone the repo
git clone --depth 1 https://github.com/vshulcz/deja-vu

Made for: Claude Code.

Or install deja-vu, the plugin that ships this one along with the rest of its 1 skill, 1 command.

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 deja-history

README.md
[![agentmods](https://agentmods.dev/badge/skills/vshulcz/deja-vu/deja-history/github.svg)](https://agentmods.dev/skills/vshulcz/deja-vu/deja-history)
Your own site
<a href="https://agentmods.dev/skills/vshulcz/deja-vu/deja-history"><img src="https://agentmods.dev/badge/skills/vshulcz/deja-vu/deja-history/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 deja-history

Your own site · 80×15
<a href="https://agentmods.dev/skills/vshulcz/deja-vu/deja-history"><img src="https://agentmods.dev/badge/skills/vshulcz/deja-vu/deja-history.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 47 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 647 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. Third-party audits
  • NVIDIA SkillSpector pass 7 Sept 2026
How audits are shown
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 $0.00047 $0.00647
Opus 5 $0.00023 $0.00324
Sonnet 5 $0.00009 $0.00129
Haiku 4.5 $0.00005 $0.00065

Measured 3d ago against content hash 324fa57b6871, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

deja-history 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.

claude-plugin/skills/deja-history/SKILL.md · 32 lines

How it starts

The opening of the file, as written. The whole thing — 32 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Search deja before re-deriving past work: when the user refers to earlier sessions or decisions, before debugging an error, and before implementing something that may already exist. It searches this machine's own history across every AI coding tool used on it, going back further than deja itself was installed.

If these tools are not available in this session, the same index is reachable through the shell: deja search --json "<query>", deja ctx <query>, deja blame <path> --json.

Finding something

  • recall: search with the most specific token available — an exact error string, function name, file path, or flag. Several words are ANDed. Not for library docs or general knowledge; only this user's own sessions.
  • recall_context: a full digest of the single best-matching session, once a recall hit looks right and the reasoning behind it matters.
  • blame: before editing, refactoring or deleting a file, the prior sessions that discussed it, so you know why it is shaped the way it is. Session history, not git authorship.
  • fix: paste a failing output verbatim to see the commands that followed that same error before, in sessions where it did not come back.
  • how: the real command with the real flags this machine runs for a build, test, deploy or script, ordered by how many sessions ran it. A guessed invocation is plausible and fails on this setup.
  • remember: store one durable decision after it is settled, as a single self-contained fact. Not transcripts, not anything already obvious from the code.

Reading a result

A result may carry a bracketed marker with a date — that is the user's own later judgement on that session, and it is not advisory. Do not repeat a rejected approach. Prefer a replacement over what it replaced. Treat a stale result as needing confirmation before acting on it. A result with no marker carries no judgement in either direction.

Saying what you used

When recalled history genuinely helps — a reused fix, a skipped re-debug, even a partial hint that changed your approach — tell the user in one short line at the start of your reply, naming the session: "déjà vu: we hit this JWT skew in March — reusing that fix (deja:a1b2c3d4-e5f)". Say nothing about recalls that did not help. This is provenance, not advertising; a note on every call would be noise.

Read the full file on GitHub · 32 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. 3d ago Changed 324fa57b6871
  2. 11d ago First seen · 32 lines · 47 tokens per session scan A b822d9d5c3df

Subscribe to this mod's changes

deja-history is a skill published in the GitHub repository vshulcz/deja-vu (799 stars, last pushed today), licensed MIT. It adds 47 tokens to every session and 647 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 2026-08-30.