Persistent Codebase Memory & Continuous Chat (v1.5.0)

DevDiff v1.5.0 introduces the Persistent Codebase Memory Engine and Continuous Chat Context, transforming DevDiff from a single-run diff tool into a persistent codebase intelligence assistant with historical memory.

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🎯 Key Capabilities

• One-Time Full Scan: Scans the workspace once and builds an indexed codebase snapshot under .devdiff/memory/codebase-index.json.
• Sub-50ms Index Queries: Instant responses for changes, entity histories, additions, purpose summaries, and dependency structures directly from memory without re-scanning code.
• Incremental Updates: Detects Git commit hash changes and updates only modified files incrementally in milliseconds.
• Continuous Conversation Context: Tracks chat turns across sessions in .devdiff/memory/conversation-history.json, automatically resolving pronouns (it, this, that) to previously discussed entities.
• Historical Snapshot Graph: Maintains project snapshots over time in .devdiff/memory/snapshot-history.json, enabling historical comparisons ("What was the project like in June?").

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🚀 CLI Commands

1. Persistent Memory Commands (devdiff memory)

# Perform one-time full codebase scan and build persistent index
devdiff memory init

# View persistent memory status, indexed file counts, and entity statistics
devdiff memory status

# List snapshots in a date range or category (v1.7.0)
devdiff memory list --from 08-01 --to 08-15 --category production

# Delete memory snapshots for a specific time range (v1.7.0)
devdiff memory delete --from 03-01 --to 03-15 --dry-run

# Restrict active context to a specific period (v1.7.0)
devdiff memory use --from 04-01 --to 04-30
devdiff memory use --all

# Categorize snapshot time ranges with labels (v1.7.0)
devdiff memory categorize --from 03-01 --to 03-15 --label "experimentation"
devdiff memory categories

# Storage optimization and deduplication (v1.7.0)
devdiff memory optimize

2. Instant Memory Queries (devdiff ask)

# Query changes over time
devdiff ask "What changed since yesterday?"

# Query entity history timeline
devdiff ask "Show me the history of UserService"

# Query entity creation date
devdiff ask "When was the auth module added?"

# Query entity purpose
devdiff ask "What does authenticateUser do?"

# Query historical snapshot
devdiff ask "What was the project like in June?"

# Continuous chat with pronoun resolution
devdiff ask "Show me the history of PersistentMemory"
devdiff ask "What does it depend on?" # Resolves "it" to PersistentMemory

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🧠 Memory Storage Architecture

All persistent memory assets are stored inside the project workspace under .devdiff/memory/:

File Path	Description
.devdiff/memory/codebase-index.json	Current indexed snapshot (entities, AST declarations, lines, dependency map).
.devdiff/memory/snapshot-history.json	Array of historical codebase snapshots over time.
.devdiff/memory/conversation-history.json	Session conversation turns for pronoun resolution.

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📊 Performance Benchmark

Operation	Standard Re-Scan	Persistent Memory (v1.5.0)
Initial Full Scan	30–60s	200ms – 4s (one-time)
Incremental Update	30s	< 50ms
Entity Lookup	15–30s	< 5ms
Change History Query	20s	< 15ms
Context Resolution	N/A (Forgotten)	< 1ms