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.

Selvedge is a local MCP server. AI coding agents (Claude Code, Cursor, Copilot) call it as they work to log structured change events with reasoning. Your data stays in a SQLite file under .selvedge/ next to your code.

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 v0.3.5

The recovery-basics release. v0.3.1 made the runtime safe; v0.3.2 made problems visible; v0.3.5 ships the minimum viable "what happens when something has gone wrong" surface. Drop-in upgrade for anyone on 0.3.4.

selvedge verify — DB-correctness gate with two exit tiers. Walks the store and reports each check as PASS / WARN / FAIL. Must-fail conditions (SQLite corruption, schema mismatch against the declared MIGRATIONS, empty entity_path, unknown change_type in the store, unparseable timestamps, malformed tool_calls rows) exit non-zero. Should-warn conditions (singleton changeset_id groups, events past the 60-minute backfill window with no git_commit) print warnings but exit 0 by default. Pass --strict to escalate warnings to failures — the tiering means selvedge verify can drop into CI on day one without || true. --json for machine output.

selvedge backup — online SQLite snapshot via VACUUM INTO. Default destination .selvedge/backups/selvedge-YYYYMMDD-HHMMSS.db, kept out of git because selvedge init now appends .selvedge/backups/ to the project .gitignore (and the first selvedge backup run on an existing repo appends it the same way — idempotent). Hardcoded keep_last=7 for this release; the setting becomes backup_keep_last in .selvedge/config.toml when that file lands in v0.3.10. --output <path> overrides the default and is excluded from rotation so ad-hoc destinations aren't swept up. Two backups in the same second don't collide.

Doctor — Last backup row. INFO when the newest backup is ≤7 days old, WARN when older, FAIL when no backups exist and the events table has ≥10,000 rows (the threshold where no-backups becomes a real data-loss exposure rather than a CI/scratch DB).

Doctor — Schema version now FAILs on downgrade. When schema_migrations contains a version not declared in the current MIGRATIONS tuple, the row fails rather than silently passing — surfaces "this DB was last opened by a newer Selvedge" before any write attempts schema work it doesn't understand.

See CHANGELOG.md for the full list including the 24 new tests across test_verify.py, test_backup.py, and the test_doctor.py extension.

What's new in v0.3.4

The first-run release. The install funnel was six manual steps with three documentation lookups; v0.3.4 collapses it to one command. Drop-in upgrade for anyone on 0.3.3.

selvedge setup — interactive first-run wizard. Detects which AI tools are already on your machine (Claude Code, Cursor, Copilot) and walks through every install step in one pass: writes the MCP entry into each tool's config, drops the canonical agent-instructions block into your project's CLAUDE.md / .cursorrules / copilot-instructions file, runs selvedge init if needed, installs the post-commit hook. Every modified file gets a .bak next to it before any change reaches disk; re-running is a no-op. For CI bootstrap and devcontainer postCreateCommand: selvedge setup --non-interactive --yes.

selvedge prompt — canonical agent instructions on tap. Prints the recommended system-prompt block to stdout, or installs it idempotently into a target file with --install <file>. The block is sentinel-bracketed (<!-- selvedge:start --> / <!-- selvedge:end -->), so re-running --install updates the bracketed region without disturbing the rest of the file. No more copy-paste drift between releases.

selvedge watch — live tail of new events. Polls the SQLite store at --interval (default 1s) and prints each new event as it lands, Rich-formatted. Filters mirror selvedge history exactly: --since, --entity, --project, --agent. --json for piping into jq. Ctrl-C exits cleanly. Trust-but-verify surface for users who want to see what their agent is actually capturing in real time, and a much better debugging tool than running selvedge status repeatedly.

Better empty-state diagnosis in selvedge status and doctor. The "no events yet" message now distinguishes "MCP entry installed but agent hasn't reloaded" (5-minute restart-your-agent grace) from "MCP entry not installed anywhere we can see" (run selvedge setup). Surfaces the actual config path in either case so you know where to look.

See CHANGELOG.md for the full list including the test-coverage additions (54 new tests across test_setup.py, test_prompt.py, test_watch.py).

Where Selvedge fits

AI agents call Selvedge as they work. Selvedge captures the why into a durable, queryable store and emits it back out — as Agent Trace records for cross-tool readers, as observability metadata that links into Sentry/Datadog stack traces, and as compliance artifacts for SOC 2 and EU AI Act audits.

Selvedge does not replace git (line-level what/when), PR review tools (review-time quality), agent observability (LLM call traces), or general-purpose code-host AI features. It sits between them — the provenance-as-first-class-citizen layer that everything else references.

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.

Quickstart

pip install selvedge
cd your-project
selvedge setup

That's it. selvedge setup is an interactive wizard: it detects which AI tools you have (Claude Code, Cursor, Copilot), writes the MCP entry into each one's config, drops the canonical agent-instructions block into your project's prompt file (CLAUDE.md / .cursorrules / copilot-instructions.md), runs selvedge init, and installs the post-commit hook. Every modified file gets a .bak written next to it before any change reaches disk. Re-running is a no-op.

For CI bootstrap or devcontainer.json postCreateCommand:

selvedge setup --non-interactive --yes

Verify the wiring — open a second terminal in the same project:

selvedge watch

Make any change in your AI tool — add a column, rename a function, add an env var. selvedge watch should print the new event within a second of the agent calling log_change. If nothing arrives, run selvedge doctor for a single-command health check that tells you which step is silently broken.

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 (per-agent)
selvedge import migrations/            # backfill from migration files
selvedge export --format csv           # dump history to CSV

If you don't want to run the wizard, the four manual steps it automates:

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"
    }
  }
}

For Cursor: ~/.cursor/mcp.json. For Copilot: .github/copilot-instructions.md (different format — see selvedge prompt --help).

3. Tell your agent to use it

selvedge prompt --install CLAUDE.md

This installs the canonical agent-instructions block, sentinel-bracketed (<!-- selvedge:start --> / <!-- selvedge:end -->) so future --install calls update the bracketed region without disturbing anything else in the file. Or pipe it:

selvedge prompt | tee -a CLAUDE.md

4. Install the post-commit hook

selvedge install-hook

That's the same four steps the wizard runs.

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 (per-tool, per-agent)
selvedge doctor [--json]                  Health check: DB path, schema, hook, MCP wiring
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.