diff --git a/docs/implementation-roadmap.md b/docs/implementation-roadmap.md
index 129f7f8..815d9da 100644
--- a/docs/implementation-roadmap.md
+++ b/docs/implementation-roadmap.md
@@ -37,6 +37,7 @@ As of now:
 - Phase 2 frontend work has now started by bootstrapping `apps/web` with copied-in `cadence-ui` tokens and foundational components for button, input, textarea, dialog, form, tabs, card, badge, and alert, with the shared token stylesheet loaded from the frontend entrypoint
 - the first real Phase 2 read-only operator UI is now implemented in `apps/web`, including routed runs list, run detail, blocked queue, and thread timeline views backed by the existing `orchd` HTTP API, plus Tailwind v4 consumer wiring so the source-owned Cadence UI components render correctly in the app
 - a repository-level skill workspace monorepo migration plan now exists under `docs/skill-workspace-monorepo.md`, defining the target split between runtime packages under `packages/`, agent-facing skill bundles under `skills/`, support apps under `apps/`, and package-based skill packaging flows
+- the first migration phase for the skill workspace monorepo is now complete: root `go.work` exists, `pnpm-workspace.yaml` now discovers `packages/*`, empty runtime module roots now exist under `packages/`, and a declarative `scripts/skill-bundles.json` plus `scripts/package_skill_runtimes.sh` scaffold now define package-oriented skill bundle metadata from the repo root
 - a repo-local `scripts/package_skill_clis.sh` packaging flow now builds bundled skill CLI assets for `inbox`, `orch`, and `council-review`
 - `orch` now implements `run init/show`, `task add`, `dep add`, `ready`, `dispatch`, `reconcile`, `wait`, `blocked`, `answer`, `retry`, `reassign`, `cancel`, `cleanup`, and `status`
 - `orch` can create runs, gate tasks through dependencies, dispatch work through `inbox`, reconcile worker thread state back into task state, answer blocked tasks, retry or reassign work, cancel tasks or runs, clean attempt worktrees, and create per-attempt Git worktrees during strict dispatch
@@ -96,9 +97,9 @@ Current implementation status:
 - `Milestone 7: Council Review` is complete
 - `Milestone 8: Web Product Phase 1 Skeleton` is complete
 - `Milestone 9: Web Product Phase 2 Read-Only Operator UI` is complete for the initial operator surface
-- `Milestone 10: Skill Workspace Monorepo Migration` is planned
+- `Milestone 10: Skill Workspace Monorepo Migration` is in progress
 
-The council review v1 surface is complete, the first web-product skeleton now exists as a separate monorepo workspace plus read-only HTTP backend slice, the first real operator-facing Phase 2 read-only web views now exist on top of the internal Cadence UI component library, and the repository now has an explicit migration plan for becoming a true skill workspace monorepo.
+The council review v1 surface is complete, the first web-product skeleton now exists as a separate monorepo workspace plus read-only HTTP backend slice, the first real operator-facing Phase 2 read-only web views now exist on top of the internal Cadence UI component library, and the repository has now started the actual migration into a true skill workspace monorepo.
 
 ### Milestone 1: Go Skeleton
 
@@ -482,34 +483,38 @@ Definition of done:
 
 Status:
 
-- planned
+- in progress
 
 Completed so far:
 
 - the repository-level migration design is captured in `docs/skill-workspace-monorepo.md`
 - the target package split now distinguishes `coord-core`, runtime packages, skill bundles, and support apps
 - the migration plan now defines phased extraction for `coord-core`, `inbox-runtime`, `orch-runtime`, `orchd-runtime`, and `repo-memory-runtime`
+- root `go.work` now includes the current root module plus the initial runtime package module roots under `packages/`
+- `pnpm-workspace.yaml` now includes `packages/*`, and root `package.json` now exposes monorepo bundle planning and validation scripts
+- initial module roots now exist for `packages/coord-core`, `packages/inbox-runtime`, `packages/orch-runtime`, `packages/orchd-runtime`, and `packages/repo-memory-runtime`
+- `scripts/skill-bundles.json` now records the first package-oriented skill bundle metadata, including the future `repo-memory` runtime mapping
+- `scripts/package_skill_runtimes.sh` now provides a declarative bundle plan/validate scaffold that targets package paths rather than hardcoded root runtime paths
 
 Remaining:
 
-- bootstrap `go.work` plus expanded workspace configuration
 - extract shared coordination code into `packages/coord-core`
 - extract `inbox`, `orch`, and `orchd` into package-owned runtimes
 - import `repo-memory` as its own runtime package and add the corresponding skill bundle
-- replace the hardcoded skill packaging script with declarative bundle metadata
+- graduate the bundle scaffold into the primary packaging flow once package-owned runtime entrypoints exist
 
 ## Immediate Next Task
 
 If a new agent is taking over now, the next concrete step should be:
 
 1. treat `Milestone 9: Web Product Phase 2 Read-Only Operator UI` as complete for the initial operator surface and do not expand web feature scope further until the workspace split is decided package-by-package
-2. start `Milestone 10: Skill Workspace Monorepo Migration` by bootstrapping `go.work`, expanding workspace metadata, and creating the first empty `packages/` roots
+2. treat the Phase 1 workspace bootstrap for `Milestone 10` as complete and keep the new `go.work`, `packages/`, and declarative bundle metadata as the baseline for all further migration steps
 3. extract the shared coordination kernel into `packages/coord-core` before moving `inbox`, `orch`, or `orchd` into package-owned runtimes
 4. keep the authored skill forward-test plans under `docs/tests/*-skill/` synchronized as runtime ownership moves from root paths to package paths
-5. replace the hardcoded skill packaging flow with declarative bundle metadata before adding `repo-memory`
+5. keep the legacy hardcoded packaging flow working temporarily, but evolve the new declarative bundle scaffold into the primary packaging path before adding `repo-memory`
 6. import `repo-memory` only after the package-based runtime and skill packaging pattern exists
 
-The inbox implementation and its human-readable test-plan set are already in place, `orch` supports the main scheduler loop plus the complete council start/wait/tally/report workflow, the web product now has its first real operator-facing read surfaces, and the repository now has an explicit plan to become a skill workspace monorepo, so the next step should be repository restructuring rather than continuing to accrete new root-owned runtimes.
+The inbox implementation and its human-readable test-plan set are already in place, `orch` supports the main scheduler loop plus the complete council start/wait/tally/report workflow, the web product now has its first real operator-facing read surfaces, and the repository has finished the first workspace-bootstrap phase of the skill monorepo migration, so the next step should be package extraction rather than continuing to accrete new root-owned runtimes.
 
 ## Recommended Driver Choices
 
diff --git a/docs/roadmaps/active/skill-workspace-monorepo-migration.md b/docs/roadmaps/active/skill-workspace-monorepo-migration.md
new file mode 100644
index 0000000..0c74ecd
--- /dev/null
+++ b/docs/roadmaps/active/skill-workspace-monorepo-migration.md
@@ -0,0 +1,57 @@
+# Skill Workspace Monorepo Migration
+
+## Status
+
+- `in_progress`
+
+## Owner
+
+- Codex
+
+## Started At
+
+- `2026-03-20`
+
+## Goal
+
+- Execute `Milestone 10: Skill Workspace Monorepo Migration` by moving the repository toward a true multi-package monorepo whose primary deliverables are skills and skill runtimes.
+
+## Scope
+
+- bootstrap the shared workspace structure described in `docs/skill-workspace-monorepo.md`
+- complete migration phases incrementally, committing after each completed phase
+- keep packaging, roadmap, and validation flows synchronized as the migration proceeds
+
+## Checklist
+
+- [x] create or adopt an active execution roadmap for the migration workstream
+- [x] Phase 1: bootstrap `go.work`, expanded workspace manifests, package roots, and declarative skill bundle metadata
+- [ ] Phase 2: extract shared coordination code into `packages/coord-core`
+- [ ] Phase 3: extract `inbox-runtime` and `orch-runtime`
+- [ ] Phase 4: extract `orchd-runtime`
+- [ ] Phase 5: import `repo-memory-runtime` and add `skills/repo-memory`
+- [ ] Phase 6: remove root runtime ownership and normalize package-based packaging
+
+## Files
+
+- `docs/roadmaps/active/skill-workspace-monorepo-migration.md`
+- `docs/skill-workspace-monorepo.md`
+- `docs/implementation-roadmap.md`
+- `go.work`
+- `pnpm-workspace.yaml`
+- `package.json`
+- `packages/`
+- `scripts/`
+
+## Decisions
+
+- keep one long-lived active roadmap for the full migration rather than opening a new execution trace for every individual phase
+- complete and commit one migration phase at a time so the workspace remains bisectable
+
+## Blockers
+
+- none
+
+## Next Step
+
+- start Phase 2 by extracting the shared coordination kernel into `packages/coord-core`, using the new workspace and bundle metadata scaffold as the stable base for subsequent package moves
diff --git a/go.work b/go.work
new file mode 100644
index 0000000..b301e1f
--- /dev/null
+++ b/go.work
@@ -0,0 +1,10 @@
+go 1.26
+
+use (
+	.
+	./packages/coord-core
+	./packages/inbox-runtime
+	./packages/orch-runtime
+	./packages/orchd-runtime
+	./packages/repo-memory-runtime
+)
diff --git a/package.json b/package.json
index 058c1a9..3bd7dba 100644
--- a/package.json
+++ b/package.json
@@ -3,6 +3,8 @@
   "private": true,
   "packageManager": "pnpm@10.25.0",
   "scripts": {
+    "skills:bundle:plan": "bash ./scripts/package_skill_runtimes.sh plan",
+    "skills:bundle:validate": "bash ./scripts/package_skill_runtimes.sh validate",
     "web:dev": "pnpm --filter @ai-workflow-skill/web dev",
     "web:build": "pnpm --filter @ai-workflow-skill/web build",
     "web:preview": "pnpm --filter @ai-workflow-skill/web preview",
diff --git a/packages/coord-core/go.mod b/packages/coord-core/go.mod
new file mode 100644
index 0000000..27376eb
--- /dev/null
+++ b/packages/coord-core/go.mod
@@ -0,0 +1,3 @@
+module ai-workflow-skill/packages/coord-core
+
+go 1.26
diff --git a/packages/inbox-runtime/go.mod b/packages/inbox-runtime/go.mod
new file mode 100644
index 0000000..17828b1
--- /dev/null
+++ b/packages/inbox-runtime/go.mod
@@ -0,0 +1,3 @@
+module ai-workflow-skill/packages/inbox-runtime
+
+go 1.26
diff --git a/packages/orch-runtime/go.mod b/packages/orch-runtime/go.mod
new file mode 100644
index 0000000..1c54b4d
--- /dev/null
+++ b/packages/orch-runtime/go.mod
@@ -0,0 +1,3 @@
+module ai-workflow-skill/packages/orch-runtime
+
+go 1.26
diff --git a/packages/orchd-runtime/go.mod b/packages/orchd-runtime/go.mod
new file mode 100644
index 0000000..a50b07b
--- /dev/null
+++ b/packages/orchd-runtime/go.mod
@@ -0,0 +1,3 @@
+module ai-workflow-skill/packages/orchd-runtime
+
+go 1.26
diff --git a/packages/repo-memory-runtime/go.mod b/packages/repo-memory-runtime/go.mod
new file mode 100644
index 0000000..a035387
--- /dev/null
+++ b/packages/repo-memory-runtime/go.mod
@@ -0,0 +1,3 @@
+module ai-workflow-skill/packages/repo-memory-runtime
+
+go 1.26
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
index 852bf6b..286cf7f 100644
--- a/pnpm-workspace.yaml
+++ b/pnpm-workspace.yaml
@@ -1,2 +1,3 @@
 packages:
   - apps/*
+  - packages/*
diff --git a/scripts/package_skill_runtimes.sh b/scripts/package_skill_runtimes.sh
new file mode 100644
index 0000000..13294d1
--- /dev/null
+++ b/scripts/package_skill_runtimes.sh
@@ -0,0 +1,123 @@
+#!/usr/bin/env bash
+
+set -euo pipefail
+
+readonly SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+readonly REPO_ROOT="$(cd "${SCRIPT_DIR}/.." && pwd)"
+readonly MANIFEST_PATH="${REPO_ROOT}/scripts/skill-bundles.json"
+
+usage() {
+  cat <<'EOF'
+Usage:
+  package_skill_runtimes.sh plan
+  package_skill_runtimes.sh validate
+
+Phase 1 only bootstraps declarative bundle metadata.
+Actual runtime packaging will be added once package-owned entrypoints exist.
+EOF
+}
+
+require_command() {
+  local cmd="$1"
+  if ! command -v "${cmd}" >/dev/null 2>&1; then
+    printf 'missing required command: %s\n' "${cmd}" >&2
+    exit 1
+  fi
+}
+
+emit_bundles() {
+  node -e '
+    const fs = require("node:fs");
+    const manifestPath = process.argv[1];
+    const manifest = JSON.parse(fs.readFileSync(manifestPath, "utf8"));
+    for (const bundle of manifest.bundles ?? []) {
+      const row = [
+        bundle.skill,
+        bundle.type,
+        bundle.runtimePackage,
+        bundle.entrypoint,
+        bundle.output,
+        bundle.buildState
+      ].join("\t");
+      process.stdout.write(`${row}\n`);
+    }
+  ' "${MANIFEST_PATH}"
+}
+
+plan() {
+  printf 'skill bundle plan from %s\n' "${MANIFEST_PATH}"
+  while IFS=$'\t' read -r skill type runtime_package entrypoint output build_state; do
+    printf -- '- skill=%s type=%s state=%s runtime=%s entrypoint=%s output=%s\n' \
+      "${skill}" "${type}" "${build_state}" "${runtime_package}" "${entrypoint}" "${output}"
+  done < <(emit_bundles)
+}
+
+validate() {
+  local failures=0
+
+  while IFS=$'\t' read -r skill type runtime_package entrypoint output build_state; do
+    local runtime_path="${REPO_ROOT}/${runtime_package#./}"
+    local entrypoint_path="${REPO_ROOT}/${entrypoint#./}"
+    local output_path="${REPO_ROOT}/${output}"
+
+    if [[ "${type}" != "go-binary" ]]; then
+      printf 'invalid bundle type for %s: %s\n' "${skill}" "${type}" >&2
+      failures=1
+    fi
+
+    if [[ ! -d "${runtime_path}" ]]; then
+      printf 'missing runtime package dir for %s: %s\n' "${skill}" "${runtime_package}" >&2
+      failures=1
+    fi
+
+    if [[ ! -f "${runtime_path}/go.mod" ]]; then
+      printf 'missing go.mod for %s runtime package: %s\n' "${skill}" "${runtime_package}" >&2
+      failures=1
+    fi
+
+    if [[ "${build_state}" != "planned" && ! -d "${entrypoint_path}" ]]; then
+      printf 'missing ready entrypoint for %s: %s\n' "${skill}" "${entrypoint}" >&2
+      failures=1
+    fi
+
+    if [[ "${output}" != skills/* ]]; then
+      printf 'output for %s must stay under skills/: %s\n' "${skill}" "${output}" >&2
+      failures=1
+    fi
+
+    if [[ "${build_state}" != "planned" && ! -d "$(dirname "${output_path}")" ]]; then
+      printf 'missing output parent for %s: %s\n' "${skill}" "$(dirname "${output}")" >&2
+      failures=1
+    fi
+  done < <(emit_bundles)
+
+  if [[ "${failures}" -ne 0 ]]; then
+    exit 1
+  fi
+
+  printf 'skill bundle manifest validated\n'
+}
+
+main() {
+  require_command node
+
+  local command="${1:-}"
+  case "${command}" in
+    plan)
+      plan
+      ;;
+    validate)
+      validate
+      ;;
+    ""|-h|--help|help)
+      usage
+      ;;
+    *)
+      printf 'unknown command: %s\n' "${command}" >&2
+      usage >&2
+      exit 1
+      ;;
+  esac
+}
+
+main "$@"
diff --git a/scripts/skill-bundles.json b/scripts/skill-bundles.json
new file mode 100644
index 0000000..19f8bdf
--- /dev/null
+++ b/scripts/skill-bundles.json
@@ -0,0 +1,37 @@
+{
+  "version": 1,
+  "bundles": [
+    {
+      "skill": "inbox",
+      "type": "go-binary",
+      "runtimePackage": "./packages/inbox-runtime",
+      "entrypoint": "./packages/inbox-runtime/cmd/inbox",
+      "output": "skills/inbox/assets/inbox",
+      "buildState": "planned"
+    },
+    {
+      "skill": "orch",
+      "type": "go-binary",
+      "runtimePackage": "./packages/orch-runtime",
+      "entrypoint": "./packages/orch-runtime/cmd/orch",
+      "output": "skills/orch/assets/orch",
+      "buildState": "planned"
+    },
+    {
+      "skill": "council-review",
+      "type": "go-binary",
+      "runtimePackage": "./packages/orch-runtime",
+      "entrypoint": "./packages/orch-runtime/cmd/orch",
+      "output": "skills/council-review/assets/orch",
+      "buildState": "planned"
+    },
+    {
+      "skill": "repo-memory",
+      "type": "go-binary",
+      "runtimePackage": "./packages/repo-memory-runtime",
+      "entrypoint": "./packages/repo-memory-runtime/cmd/briefdb",
+      "output": "skills/repo-memory/assets/briefdb",
+      "buildState": "planned"
+    }
+  ]
+}