Detecting and Fixing Drift

The Problem¶

Context files drift: you rename a package, delete a module, or finish a sprint, and suddenly ARCHITECTURE.md references paths that no longer exist, TASKS.md is 80 percent completed checkboxes, and CONVENTIONS.md describes patterns you stopped using two months ago.

Stale context is worse than no context:

An AI tool that trusts outdated references will hallucinate confidently.

This recipe shows how to detect drift, fix it, and keep your .context/ directory lean and accurate.

ctx drift                      # detect problems
ctx drift --fix                # auto-fix the easy ones
ctx sync --dry-run && ctx sync # reconcile after refactors
ctx compact --archive          # archive old completed tasks
ctx status                     # verify

Commands and Skills Used¶

The Workflow¶

The best way to maintain context health is conversational: ask your agent, guide it, and let it detect problems, explain them, and fix them with your approval. CLI commands exist for CI pipelines, scripting, and fine-grained control.

For day-to-day maintenance, talk to your agent.

Step 1: Ask Your Agent¶

The simplest way to check context health:

Is our context clean?
Anything stale?
How healthy are our context files?

Or invoke the skill directly:

/ctx-drift

The agent performs two layers of analysis:

Layer 1, structural checks (via ctx drift): Dead paths, missing files, completed task counts, constitution violations. Fast and programmatic.

Layer 2, semantic analysis (agent-driven): Does CONVENTIONS.md describe patterns the code no longer follows? Does DECISIONS.md contain entries whose rationale no longer applies? Are there learnings about bugs that are now fixed? This is where the agent adds value the CLI cannot: It reads both context files and source code and compares them.

The agent reports both layers together, explains each finding in plain language, and offers to fix what it can.

Step 2: Maintenance at Session Start¶

You do not need to ask explicitly. A proactive agent can check context health as part of its startup routine and mention anything worth addressing:

Agent: Good morning. I've loaded the context files. A few things
       before we start:

       - ARCHITECTURE.md references `pkg/auth/` which is now empty
       - DECISIONS.md hasn't been updated in 40 days
       - There are 18 completed tasks ready for archival

       Want me to run a quick maintenance pass, or should we jump
       straight into today's work?

If the agent does not offer this on its own, a gentle nudge is enough:

Anything stale before we start?
How's the context looking?

This turns maintenance from a scheduled chore into a conversation that happens when it matters.

Step 3: Real-Time Detection During Work¶

Agents can notice drift while working — when a mismatch is directly in the path of their current task. If an agent reads ARCHITECTURE.md to find where to add a handler and internal/handlers/ doesn't exist, it will notice because the stale reference blocks its work:

Agent: ARCHITECTURE.md references `internal/handlers/` but that directory
       doesn't exist. I'll look at the actual source tree to find where
       handlers live now.

This happens reliably when the drift intersects the task. What is less reliable is the agent generalizing from one mismatch to "there might be more stale references; let me run drift detection" That leap requires the agent to know /ctx-drift exists and to decide the current task should pause for maintenance.

If you want that behavior, reinforce it:

Good catch. Yes, run /ctx-drift and clean up any other stale references.

Over time, agents that have seen this pattern will start offering proactively. But do not expect it from a cold start.

Step 4: Archival and Cleanup¶

ctx drift detects when TASKS.md has more than 10 completed items and flags it as a staleness warning. Running ctx drift --fix archives completed tasks automatically.

You can also run /ctx-archive to compact on demand.

Step 5: Alignment Audits¶

A related problem is alignment drift: Documentation that makes claims about agent behavior not backed by actual playbook or skill instructions.

Over time, docs accumulate aspirational statements that no instruction teaches the agent to do.

Use /ctx-alignment-audit to trace behavioral claims in documentation against the playbook and skill files. The skill identifies gaps, proposes fixes, and checks instruction file health (token budgets, bloat signals).

To avoid confusion with /ctx-prompt-audit:

• /ctx-alignment-audit checks whether documentation claims are supported by actual instructions (playbook, skills, CLAUDE.md).
• /ctx-prompt-audit checks whether your context files are clear, compact, and token-efficient for the model.

CLI Reference¶

The conversational approach above uses CLI commands under the hood. When you need direct control, use the commands directly.

ctx drift¶

Scan context files for structural problems:

ctx drift

Sample output:

Drift Report
============

Warnings (3):
  ARCHITECTURE.md:14  path "internal/api/router.go" does not exist
  ARCHITECTURE.md:28  path "pkg/auth/" directory is empty
  CONVENTIONS.md:9    path "internal/handlers/" not found

Violations (1):
  TASKS.md            31 completed tasks (recommend archival)

Staleness:
  DECISIONS.md        last modified 45 days ago
  LEARNINGS.md        last modified 32 days ago

Exit code: 1 (warnings found)

Exit codes: 0 equals clean, 1 equals warnings, 3 equals violations.

For CI integration:

ctx drift --json | jq '.warnings | length'

ctx drift --fix¶

Auto-fix mechanical issues:

ctx drift --fix

This handles removing dead path references, updating unambiguous renames, clearing empty sections. Issues requiring judgment are flagged but left for you.

Run ctx drift again afterward to confirm what remains.

ctx sync¶

After a refactor, reconcile context with the actual codebase structure:

ctx sync --dry-run   # preview first
ctx sync             # apply

ctx sync scans for structural changes, compares with ARCHITECTURE.md, checks for new dependencies worth documenting, and identifies context referring to code that no longer exists.

ctx compact¶

Consolidate completed tasks and clean up empty sections:

ctx compact              # move completed tasks to Completed section, remove empty sections
ctx compact --archive    # also copy tasks older than 7 days to .context/archive/

• Tasks: moves completed items (with all subtasks done) into the Completed section of TASKS.md
• All files: removes empty sections left behind
• With --archive: also writes tasks older than 7 days to .context/archive/tasks-YYYY-MM-DD.md

Without --archive, nothing is deleted — tasks are reorganized in place.

ctx status¶

Quick health overview:

ctx status --verbose

Shows file counts, token estimates, modification times, and drift warnings in a single glance.

/ctx-alignment-audit and /ctx-prompt-audit¶

These are both audits, but they answer different questions:

• /ctx-alignment-audit: are our behavioral claims backed by actual instructions?
• /ctx-prompt-audit: are our context files readable, compact, and efficient?

Run them inside your AI assistant:

/ctx-alignment-audit
/ctx-prompt-audit

Putting It All Together¶

Conversational approach (recommended):

Is our context clean?   -> agent runs structural plus semantic checks
Fix what you can        -> agent auto-fixes and proposes edits
Archive the done tasks  -> agent runs ctx compact --archive
How's token usage?      -> agent checks ctx status

CLI approach (for CI, scripts, or direct control):

ctx drift                      # 1. Detect problems
ctx drift --fix                # 2. Auto-fix the easy ones
ctx sync --dry-run && ctx sync # 3. Reconcile after refactors
ctx compact --archive          # 4. Archive old completed tasks
ctx status                     # 5. Verify

Tips¶

Agents cross-reference context files with source code during normal work. When drift intersects their current task, they will notice: a renamed package, a deleted directory, a path that doesn't resolve. But they rarely generalize from one mismatch to a full audit on their own. Reinforce the pattern: when an agent mentions a stale reference, ask it to run /ctx-drift. Over time, it starts offering.

When an agent says "this reference looks stale," it is usually right.

Semantic drift is more damaging than structural drift. ctx drift catches dead paths. But CONVENTIONS.md describing a pattern your code stopped following three weeks ago is worse. When you ask "is our context clean?", the agent can do both checks.

Use ctx status as a quick check. It shows file counts, token estimates, and drift warnings in a single glance. Good for a fast "is everything ok?" before diving into work.

Drift detection in CI: add ctx drift --json to your CI pipeline and fail on exit code 3 (violations). This catches constitution-level problems before they reach upstream.

Do not over-compact. Completed tasks have historical value. The --archive flag preserves them in .context/archive/ so you can search past work without cluttering active context.

Sync is cautious by default. Use --dry-run after large refactors, then apply.

Next Up¶

Browsing and Enriching Past Sessions: Export session history to a browsable journal and enrich entries with metadata.

See Also¶

• Tracking Work Across Sessions: task lifecycle and archival
• Persisting Decisions, Learnings, and Conventions: keeping knowledge files current
• The Complete Session: where maintenance fits in the daily workflow
• CLI Reference: full flag documentation for all commands
• Context Files: structure and purpose of each .context/ file