diff --git a/docs/README.md b/docs/README.md
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--- a/docs/README.md
+++ b/docs/README.md
@@ -8,6 +8,15 @@ state, terminal streaming, and CDC/event infrastructure.
 Start with [architecture.md](architecture.md) for the current backend model and
 [cli/README.md](cli/README.md) for the CLI surface.
 
+## Reference docs
+
+| Doc | What it covers |
+|-----|----------------|
+| [architecture.md](architecture.md) | Current backend model, package layout, status derivation, persistence/CDC, and load-bearing rules. |
+| [cli/README.md](cli/README.md) | CLI commands and daemon control surface. |
+| [status.md](status.md) | Current implementation shape, build/test command, and next integration work. |
+| [stack.md](stack.md) | Accepted library/runtime choices, pending stack decisions, and dependencies explicitly avoided for V1. |
+
 ## Mental model
 
 Persist durable facts, derive display status:
diff --git a/docs/stack.md b/docs/stack.md
new file mode 100644
index 000000000..334c9a59d
--- /dev/null
+++ b/docs/stack.md
@@ -0,0 +1,102 @@
+# AO technical stack
+
+This is the source of truth for library and runtime choices in the AO rewrite.
+Keep this document about durable technology decisions; use `status.md` for
+implementation progress and `architecture.md` for component behavior and
+invariants.
+
+## Principles
+
+- Prefer the Go standard library until a small dependency clearly earns its
+  place.
+- Keep the backend daemon boring: explicit process control, explicit SQL,
+  narrow adapters, and observable failure modes.
+- Shell out where AO needs the user's real developer-machine behavior, especially
+  for Git and terminal multiplexers.
+- Keep high-volume terminal output out of SQLite; store structured state in the
+  database and stream/log payload-heavy data separately.
+
+## Accepted stack
+
+| Area | Decision | Status | Rationale |
+|------|----------|--------|-----------|
+| Backend language | Go 1.25.7 | Implemented | Matches `backend/go.mod`; small daemon, strong stdlib, easy local distribution. |
+| Backend core | Go stdlib | Implemented | Domain, lifecycle, session, and adapter contracts should stay dependency-light. |
+| Frontend shell | Electron + TypeScript | Implemented | Local desktop control plane paired with the daemon. |
+| Runtime adapter | `zellij` CLI via `os/exec` | Implemented | Terminal multiplexing fits long-running sessions, attach/debug workflows, and adapter isolation. |
+| Terminal PTY | `github.com/creack/pty` | Implemented | PTY-backed terminal sessions with resize/input/output control. |
+| Git/worktrees | `git` CLI via `os/exec` | Implemented | Uses real repo behavior, credentials, hooks, LFS, submodules, and user config. |
+| HTTP API | `net/http` + `github.com/go-chi/chi/v5` | Implemented | Lightweight, idiomatic router without committing AO to a large web framework. |
+| WebSocket | `github.com/coder/websocket` | Implemented | Small WebSocket library for terminal streaming. |
+| Storage | SQLite in WAL mode via `database/sql` | Implemented | Local daemon, single writer, many dashboard/API reads, no external DB setup. |
+| SQLite driver | `modernc.org/sqlite` | Implemented | Current pure-Go driver in `backend/internal/storage/sqlite`; keep it swappable behind `database/sql`. |
+| SQL generation | `github.com/sqlc-dev/sqlc` | Implemented | Hand-written SQL with generated typed methods from `backend/sqlc.yaml`. |
+| Migrations | `github.com/pressly/goose/v3` | Implemented | Simple SQL migrations for the embedded/local database. |
+| CLI | `github.com/spf13/cobra` | Implemented | Standard command structure for daemon startup, diagnostics, and admin commands. |
+| Config | stdlib environment loading + SQLite-backed state/config | Implemented / evolving | `internal/config` handles daemon env/defaults; durable product config belongs in SQLite, so no config framework is selected for V1. |
+| Logging | `log/slog` | Implemented | Stdlib structured logging before adding another logging dependency. |
+| OpenAPI generation | `github.com/swaggest/openapi-go`, `github.com/swaggest/jsonschema-go`, `gopkg.in/yaml.v3` | Implemented | Generated OpenAPI keeps route contracts close to Go DTOs. |
+| Testing | stdlib `testing` | Implemented | Keep pure domain logic and adapter contracts easy to test. |
+| Test assertions | `github.com/stretchr/testify/require` | Planned if needed | Concise assertions for higher-level adapter and integration tests; do not add unless tests benefit. |
+| Packaging | `github.com/goreleaser/goreleaser` | Planned | Cross-platform release automation, checksums, and future Homebrew support. |
+
+## Pending decisions
+
+### SQLite driver validation
+
+Current main uses `modernc.org/sqlite`. Before release packaging is locked,
+validate `github.com/ncruces/go-sqlite3/driver` against AO's WAL, migration,
+and `change_log`/CDC workload. It is the preferred no-CGO candidate if it passes
+compatibility and performance checks.
+
+Keep the driver behind `database/sql` so the persistence layer can switch
+drivers without changing store interfaces.
+
+Required SQLite setup:
+
+```sql
+PRAGMA journal_mode = WAL;
+PRAGMA busy_timeout = 5000;
+PRAGMA foreign_keys = ON;
+PRAGMA synchronous = NORMAL;
+```
+
+### Config model
+
+Current daemon config is stdlib env/default loading. Project and product config
+should be persisted in SQLite when it needs durability or user editing. Do not
+add `github.com/spf13/viper` or `github.com/knadh/koanf` unless a real file-based
+config surface appears.
+
+## Explicitly avoided for V1
+
+| Avoid | Reason |
+|-------|--------|
+| GORM | AO needs explicit transactional SQL and CDC-triggered writes. |
+| Gin/Fiber | `net/http` + `chi` is enough for a local daemon API. |
+| `go-git` as the primary Git engine | AO should match installed Git behavior, credentials, hooks, LFS, submodules, and user config. |
+| `github.com/spf13/viper` / `github.com/knadh/koanf` by default | Env/default loading plus SQLite-backed config is enough for V1. |
+| Temporal / NATS / Kafka / Redis | V1 is a local daemon with SQLite and CDC, not a distributed control plane. |
+| Full plugin framework | Keep adapter interfaces narrow until product needs justify a plugin runtime. |
+| Multi-sink CDC fan-out | Start with one durable local delivery path; add fan-out later if needed. |
+
+## Current stack mapping
+
+```txt
+Go daemon
+  net/http + github.com/go-chi/chi/v5
+  github.com/coder/websocket
+  github.com/creack/pty
+  zellij runtime adapter via os/exec
+  git worktree adapter via git CLI
+  SQLite via database/sql + modernc.org/sqlite
+  github.com/sqlc-dev/sqlc generated queries
+  github.com/pressly/goose/v3 migrations
+  log/slog
+  github.com/spf13/cobra CLI
+  SQLite change_log + CDC poller
+```
+
+This stack supports the current architecture: durable session/PR/project facts,
+derived display status, SQLite `change_log` CDC, terminal sessions, and real Git
+worktrees.