Selvedge

Long-term memory for AI-coded codebases. A git blame for AI agents — but for the why, not just which line which model touched. Captured live, by the agent, as the change happens.

Six months ago, your AI agent added a column called user_tier_v2. You don't know why. git blame points to a commit from claude-code with a generated message that says "Update schema." The session that made the change is long gone — and so is the prompt that produced it.

With Selvedge, you run this instead:

$ selvedge blame user_tier_v2

  user_tier_v2
  Changed     2025-10-14 09:31:02
  Agent       claude-code
  Commit      3e7a991
  Reasoning   User asked to add a grandfathering flag for legacy free-tier
              users during the pricing migration. Stores the original tier
              so we can backfill discounts without touching billing history.

That reasoning was captured by the agent in the moment — written into Selvedge from the same context that produced the change. Not inferred from the diff afterward by a second LLM. Not a hand-typed commit message.

Who Selvedge is for

Selvedge has two audiences. Same tool, same pip install, same SQLite file under .selvedge/. Different scale of pain.

Teams running long-term, AI-coded codebases. When the project is big enough that you (or someone else) will touch it again in six months, twelve months, three years — but most of it was written by an agent whose context evaporated the day each PR shipped. git blame tells you what changed. Selvedge tells you why — even after the agent session, the prompt template, the developer who asked for it, and the model version are all long gone. This is the original use case: production codebases, schema decisions, migrations, dependency changes that need an audit trail that survives turnover.

Solo developers using Claude Code on everyday projects. Side projects, weekend builds, the small internal tool you keep poking at. You don't need enterprise governance — you just need to remember why you (or your agent) did the thing you did yesterday, last week, last sprint. Run selvedge init once. Add four lines to your CLAUDE.md. From then on, selvedge blame is muscle memory — a way to talk to your past self when your past self was an LLM.

If you've ever come back to your own AI-built project and thought "what was this for again?", Selvedge is the missing piece.

The problem

Human-written code leaks intent everywhere — commit messages, PR descriptions, inline comments, the Slack thread that preceded it. AI-written code doesn't. The agent has perfect clarity about why it made each decision, but that context lives in the prompt and evaporates when the conversation ends.

Six months later, your team is debugging a schema decision with no trail. git blame tells you what changed and when. It can't tell you why.

Selvedge captures the why — live, by the agent itself, as the change is made. The diff is git's job. The why is Selvedge's.

What's new in v0.3.1

A hardening release — no new feature surface, but Selvedge is now safe to run in long-lived agent pools that hammer the database from multiple threads. Drop-in upgrade for anyone on 0.3.0.

Concurrent writes no longer blow up. Every storage write is wrapped in a database is locked retry with exponential backoff, on top of WAL mode and a 5-second PRAGMA busy_timeout. The new tests/test_concurrency.py spawns 8 threads writing 25 events each and asserts all 200 land — that test reliably failed before this release.

Real schema versioning. The previous try: ALTER TABLE ... except: pass pattern has been replaced with an explicit schema_migrations table that records every applied migration with version, name, and timestamp. Partial failures roll back atomically. Pre-versioning databases are bootstrapped without re-running DDL.

Structured logging. Set SELVEDGE_LOG_LEVEL=DEBUG (or INFO, WARNING, ERROR) to see what's happening inside the storage and migration layers. All library modules log under the selvedge.* namespace — entry points configure a stderr handler at startup.

Public API surface. Library users can now import the supported surface from the top-level package:

from selvedge import (
    SelvedgeStorage, ChangeEvent, ChangeType, EntityType,
    get_db_path, parse_time_string, check_reasoning_quality,
)

The frozen surface is locked in by tests/test_public_api.py — accidental removals fail CI.

MCP protocol smoke tests. A new test suite boots the real selvedge-server subprocess and round-trips every tool over the actual JSON-RPC stdio transport. Catches contract drift the in-process tests miss.

CI gates. ruff, mypy, and an 85% coverage floor are now enforced on every PR. Current coverage is 92%.

One sneaky regex fix. The reasoning-quality validator's ^fixed?$ pattern was supposed to match "fix" and "fixed" but actually matched "fixe"/"fixed" — the ? only made the trailing d optional. Same bug in the add, remove, update, change, and see ... patterns. Rewritten as ^fix(?:ed)?$ etc. Reasoning placeholders that slipped through before now get flagged.

What's new in v0.3.0

A correctness and data-quality release — no new feature surface, but several silent-wrong-answer bugs are now fixed. Recommended upgrade for everyone on 0.2.x.

Time parsing now follows every other CLI's convention. 5m means 5 minutes, not 5 months. Use 5mo (or 5mon) for months. Unparseable inputs like --since yesterday now exit with a clear error instead of silently returning empty results from a string-vs-string compare.

selvedge history --since 15m    # last 15 minutes (was: last ~15 months)
selvedge history --since 5mo    # last 5 months
selvedge history --since 1y     # last year

search() no longer treats _ as a wildcard. Searching for stripe_customer_id used to match stripeXcustomerXid, stripeYcustomerYid, and so on, because SQL LIKE treats underscore as "any single character." All LIKE queries now ESCAPE '\' and escape the input — so the literal underscore in your column name does what you expect.

selvedge import finally works for columns defined in CREATE TABLE. Previously, importing CREATE TABLE users (id INT, email TEXT) produced exactly one event — for the table — and zero for its columns. Six months later, selvedge blame users.email returned "no history found." Now every column in a CREATE TABLE (and every sa.Column(...) in op.create_table) gets its own column.add event.

Timestamps normalized to UTC on write. Mixed-timezone events (2025-01-01T09:00:00-08:00 vs 2025-01-01T10:00:00+00:00) now sort correctly by real time. Previously they sorted by ASCII order of the timezone suffix.

Two events on rename, not one. Both SQL ALTER TABLE old RENAME TO new and Alembic op.rename_table('old', 'new') now emit a rename event for the old name and a create event for the new name — so selvedge blame new_name returns the rename context instead of "no history found."

Schema migration on rename for git_commit coverage. The post-commit hook's default lookback widened from 10 to 60 minutes — long agent sessions no longer lose their git stamp. selvedge status now surfaces the count of events still missing a git_commit so unstamped events are visible at a glance.

Validation in ChangeEvent. Empty entity_path, hallucinated change_type values like "banana", and typos like "modifyed" are now rejected at write time instead of silently inserting orphan rows.

Faster bulk imports. selvedge import wraps inserts in a single transaction (storage.log_event_batch) — orders of magnitude faster on large Alembic histories, and atomic.

Better project DB resolution. get_db_path now walks up looking for the actual selvedge.db file rather than just the .selvedge/ directory. A stray empty .selvedge/ upstream no longer hijacks resolution. Falling back to the global ~/.selvedge/selvedge.db prints a one-time stderr warning so unintentional global use is visible. (Set SELVEDGE_QUIET=1 to suppress.)

Adversarial test suite. 25 new tests covering the bug classes above, so these regressions stay fixed.

See CHANGELOG.md for the full list and reasoning.

How Selvedge compares

There's a fast-growing "git blame for AI agents" category. Here's where Selvedge fits — and where it deliberately doesn't.

Why "captured live" matters. AgentDiff and Origin generate reasoning after the change is made, by feeding the diff back to a second LLM call. Selvedge's reasoning is the agent's own intent, written from the same context window that produced the change — no inference, no hallucinated explanations, and an empty reasoning field is itself a useful signal (the agent didn't have one).

Why "entity-level" matters. Most tools attribute lines. Selvedge attributes things you actually search for: users.email, env/STRIPE_SECRET_KEY, api/v1/checkout, deps/stripe. The first question after git blame is usually "what's the history of this column", not "what's the history of lines 40–48 of users.py".

Why "changesets" matter. A Stripe billing rollout touches the users table, two new env vars, three new API routes, one dependency, and four functions across the codebase. Tag every event with changeset:add-stripe-billing and you can pull the entire scope back later — even if the original PR was broken into eight smaller ones over a month.

Selvedge ↔ Agent Trace. Agent Trace (Cursor + Cognition AI, RFC Jan 2026, backed by Cloudflare, Vercel, Google Jules, Amp, OpenCode, and git-ai) is an emerging open standard for AI code attribution traces. Selvedge isn't a competitor to it — it's a compatible producer. The design for selvedge export --format agent-trace is at docs/agent-trace-interop.md. Agent Trace is the wire format. Selvedge is the live capture + query layer that emits it.

Install

pip install selvedge

Quickstart

1. Initialize in your project

cd your-project
selvedge init

2. Add to your Claude Code config

~/.claude/config.json:

{
  "mcpServers": {
    "selvedge": {
      "command": "selvedge-server"
    }
  }
}

3. Tell your agent to use it

Add to your project's CLAUDE.md:

You have access to Selvedge for change tracking.
Call selvedge.log_change immediately after adding, modifying, or removing
any DB column, table, function, API endpoint, dependency, or env variable.
Set `reasoning` to the user's original request or the problem being solved.
Set `agent` to "claude-code".
Before modifying an entity, call selvedge.blame to understand its history.

4. Query your history

selvedge status                        # recent activity + missing-commit count
selvedge diff users                    # all changes to the users table
selvedge diff users.email              # changes to a specific column
selvedge blame payments.amount         # what changed last and why
selvedge history --since 30d           # last 30 days of changes
selvedge history --since 15m           # last 15 minutes ('m' = minutes)
selvedge changeset add-stripe-billing  # all events for a feature/task
selvedge search "stripe"               # full-text search
selvedge stats                         # log_change coverage report
selvedge install-hook                  # auto-link commits to events
selvedge import migrations/            # backfill from migration files
selvedge export --format csv           # dump history to CSV

How it works

Selvedge runs as an MCP server. AI agents in tools like Claude Code call Selvedge's tools as they work — logging structured change events to a local SQLite database.

Each event records:

• What changed (entity path, change type, diff)
• When (timestamp)
• Who (agent, session ID)
• Why (reasoning — captured from the agent's context in the moment)
• Where (git commit, project)

The diff is git's job. The why is Selvedge's.

Entity path conventions

users.email           DB column (table.column)
users                 DB table
src/auth.py::login    Function in a file (path::symbol)
src/auth.py           File
api/v1/users          API route
deps/stripe           Dependency
env/STRIPE_SECRET_KEY Environment variable

Prefix queries work everywhere: users returns users, users.email, users.created_at, and any other entity under the users. namespace.

MCP tools

When connected as an MCP server, Selvedge exposes:

CLI reference

selvedge init [--path PATH]               Initialize in project
selvedge status                           Recent activity summary
selvedge diff ENTITY [--limit N]          Change history for entity
selvedge blame ENTITY                     Most recent change + context
selvedge history [--since SINCE]          Browse all history
              [--entity ENTITY]
              [--project PROJECT]
              [--changeset CS]
              [--summarize]
              [--limit N]
selvedge changeset [CHANGESET_ID]         Show events in a changeset
                  [--list]                or list all changesets
                  [--project NAME]
                  [--since SINCE]
selvedge search QUERY [--limit N]         Full-text search
selvedge stats [--since SINCE]            Tool call coverage report
selvedge install-hook [--path PATH]       Install git post-commit hook
                     [--window MIN]       (default 60 minutes)
selvedge backfill-commit --hash HASH      Backfill git_commit on recent events
                        [--window MIN]    (default 60 minutes)
selvedge import PATH                      Import migration files (SQL / Alembic)
              [--format auto|sql|alembic]
              [--project NAME]
              [--dry-run]
selvedge export [--format json|csv]       Export history to JSON or CSV
              [--since SINCE]
              [--entity ENTITY]
              [--output FILE]
selvedge log ENTITY CHANGE_TYPE           Manually log a change
             [--diff TEXT]                CHANGE_TYPE: add, remove, modify,
             [--reasoning TEXT]           rename, retype, create, delete,
             [--agent NAME]               index_add, index_remove, migrate
             [--commit HASH]
             [--project NAME]
             [--changeset CS]

All read commands support --json for machine-readable output.

Relative time in --since:

• 15m → last 15 minutes (m = minutes)
• 24h → last 24 hours
• 7d → last 7 days
• 5mo → last 5 months (mo or mon = months)
• 1y → last year

Unparseable inputs (e.g. --since yesterday) exit with a clear error rather than silently returning empty results. ISO 8601 timestamps are also accepted and normalized to UTC.

Configuration

Coverage checking

Wondering how often your agent actually calls log_change? Two ways to check:

# Quick summary in the terminal
selvedge stats

# Cross-reference against git commits
python scripts/coverage_check.py --since 30d

The coverage script compares your git log against Selvedge events and shows which commits have associated change events. Low coverage usually means the system prompt needs strengthening — see docs/fallbacks.md for guidance.

Contributing

git clone https://github.com/masondelan/selvedge
cd selvedge
pip install -e ".[dev]"
pytest

See CLAUDE.md for architecture details and the phase roadmap.

License

MIT — see LICENSE.