CTX — Agent History Search
Search local coding-agent session history before acting, with citation discipline
Test report
- Verdict
- Works with setup
- Score
- Tested
- Jul 20, 2026
- Environment
- Claude Code 2.x (agent harness)
⚠ This skill is no longer available upstream. Our re-check on Aug 10, 2026 couldn't find it any more (SKILL.md not found in repo tree). The test below is what we measured on Jul 20, 2026 and we're leaving it up as a record — but there is nothing left to install, so we've removed the command.
SKILL.md fetched in full and is self-contained (no relative file refs to break) — install layer is a clean copy, files verified present in the repo tree. Trigger boundary is sharp: fires for 'did a prior session already try this fix / research my agent history on X', not for web search or git log. OUTPUT vs baseline NOT measured (not a measured loss): running it needs the `ctx` CLI via `curl -fsSL https://ctx.rs/install | sh` — an external install-and-execute I did not run. Baseline without ctx = crude grep over ~/.claude transcripts; the skill's indexed search + SQL views + strict citation/no-invention rules are clearly stronger by design but unverified at runtime. Docs are unusually honest: explicit 'do not invent results', JSON-context-cost warnings, privacy rules for ~/.ctx. Verdict setup because the skill files install cleanly but the value depends on installing the ctx CLI.
Scored on four weighted criteria — install, triggering, output vs. baseline, docs. How scoring works
- Installs cleanly 4/5
- Triggers reliably 5/5
- Output vs. baseline 5/10
- Docs & honesty 5/5
What CTX — Agent History Search does
Wraps the `ctx` CLI so an agent can search prior local coding-agent transcripts (decisions, attempts, failures, source citations) before starting work, and can write read-only history-research reports across sessions. Triggers when past sessions may hold relevant context or when asked to research a topic across local agent history. Needs the `ctx` CLI installed (curl | sh); degrades honestly when absent.
How to install CTX — Agent History Search
Nothing to install: the source repository no longer has this skill. If the author brings it back, our daily re-check will pick it up and the command will reappear here.
Commands — how to trigger CTX — Agent History Search
-
/ctx-history-searchSearch local coding-agent session history before acting, with citation discipline
It also activates on plain-language prompts like these:
-
Search my past coding agent sessions for that fix -
Find where I solved this bug in a previous session -
Search my local agent history for that config change
Frequently asked questions
- Is the CTX — Agent History Search skill free?
- Yes. The skill itself is free from ctxrs/ctx. SkillProof publishes the install command and an independent test verdict at no cost.
- Does CTX — Agent History Search work with Claude Code?
- We tested it with Claude Code 2.x (agent harness) on Jul 20, 2026. Verdict: Works with setup. SKILL.md fetched in full and is self-contained (no relative file refs to break) — install layer is a clean copy, files verified present in the repo tree. Trigger boundary is sharp: fires for 'did a prior session already try this fix / research my agent history on X', not for web search or git log. OUTPUT vs baseline NOT measured (not a measured loss): running it needs the `ctx` CLI via `curl -fsSL https://ctx.rs/install | sh` — an external install-and-execute I did not run. Baseline without ctx = crude grep over ~/.claude transcripts; the skill's indexed search + SQL views + strict citation/no-invention rules are clearly stronger by design but unverified at runtime. Docs are unusually honest: explicit 'do not invent results', JSON-context-cost warnings, privacy rules for ~/.ctx. Verdict setup because the skill files install cleanly but the value depends on installing the ctx CLI.
- What is the CTX — Agent History Search SkillProof Score?
- 7.6/10 — installs cleanly 4/5, triggers reliably 5/5, output vs. baseline 5/10, docs & honesty 5/5.
- How do I install CTX — Agent History Search?
- Copy the install command from this page, run it in your terminal, and restart Claude Code. Skills live in ~/.claude/skills/ (global) or .claude/skills/ inside a project.
- Can I use CTX — Agent History Search with Cursor, Copilot, Gemini CLI, Codex or other AI tools?
- The SKILL.md format is native to Claude (Claude Code, Desktop, claude.ai). The instructions inside adapt to other assistants: Cursor rules, GitHub Copilot instructions, Windsurf rules, Custom GPTs, AGENTS.md for OpenAI Codex, and GEMINI.md for Google Gemini CLI — our conversion guides cover each, and the free converter on the tools page does the wrapping for you.