diff --git a/internal/repository/oidc.go b/internal/repository/oidc.go
new file mode 100644
index 0000000..6f2d2d8
--- /dev/null
+++ b/internal/repository/oidc.go
@@ -0,0 +1,94 @@
+package repository
+
+import (
+	"context"
+	"errors"
+
+	oidcdomain "github.com/certctl-io/certctl/internal/auth/oidc/domain"
+)
+
+// Sentinel errors for the OIDC repositories. Postgres implementations
+// translate SQLSTATE codes into these so handler / service code can
+// branch via errors.Is.
+var (
+	// ErrOIDCProviderNotFound: Get / GetByName returned no row. HTTP 404.
+	ErrOIDCProviderNotFound = errors.New("oidc: provider not found")
+
+	// ErrOIDCProviderDuplicateName: Create tripped the (tenant_id, name)
+	// UNIQUE constraint. HTTP 409.
+	ErrOIDCProviderDuplicateName = errors.New("oidc: provider with this name already exists in tenant")
+
+	// ErrOIDCProviderInUse: Delete failed because at least one users row
+	// references the provider via oidc_provider_id (FK ON DELETE
+	// RESTRICT). HTTP 409.
+	ErrOIDCProviderInUse = errors.New("oidc: provider has authenticated users; revoke all sessions before delete")
+
+	// ErrGroupRoleMappingNotFound: Get returned no row. HTTP 404.
+	ErrGroupRoleMappingNotFound = errors.New("oidc: group-role mapping not found")
+
+	// ErrGroupRoleMappingDuplicate: Add tripped the
+	// (provider_id, group_name, role_id) UNIQUE constraint. HTTP 409.
+	ErrGroupRoleMappingDuplicate = errors.New("oidc: group-role mapping already exists")
+)
+
+// OIDCProviderRepository wraps the oidc_providers table. Phase 3's
+// OIDCService consumes List + Get to look up the IdP for token
+// validation; the GUI / CLI wire Create / Update / Delete behind
+// auth.oidc.* permission gates per Phase 5.
+type OIDCProviderRepository interface {
+	// List returns every configured provider in the tenant. Order:
+	// created_at ASC for stable GUI rendering.
+	List(ctx context.Context, tenantID string) ([]*oidcdomain.OIDCProvider, error)
+
+	// Get returns one provider by id. ErrOIDCProviderNotFound on miss.
+	Get(ctx context.Context, id string) (*oidcdomain.OIDCProvider, error)
+
+	// GetByName returns one provider by (tenant_id, name).
+	// ErrOIDCProviderNotFound on miss.
+	GetByName(ctx context.Context, tenantID, name string) (*oidcdomain.OIDCProvider, error)
+
+	// Create persists a new provider. Caller MUST have already called
+	// p.Validate() and encrypted the client_secret_encrypted byte
+	// stream via internal/crypto/encryption.go. Returns
+	// ErrOIDCProviderDuplicateName when the (tenant_id, name) UNIQUE
+	// constraint fires.
+	Create(ctx context.Context, p *oidcdomain.OIDCProvider) error
+
+	// Update writes the full mutable field set back to the row.
+	// Immutable fields (id, tenant_id, created_at) are read-only;
+	// updated_at is set to NOW() by the implementation.
+	Update(ctx context.Context, p *oidcdomain.OIDCProvider) error
+
+	// Delete removes a provider by id. Returns ErrOIDCProviderInUse
+	// when at least one users row references this provider (FK ON
+	// DELETE RESTRICT). Phase 5's handler maps to HTTP 409.
+	Delete(ctx context.Context, id string) error
+}
+
+// GroupRoleMappingRepository wraps the group_role_mappings table.
+// Phase 3's OIDCService.HandleCallback uses Map() to translate IdP
+// group claims into role IDs; the GUI / CLI wire ListByProvider /
+// Add / Remove for operator configuration.
+type GroupRoleMappingRepository interface {
+	// ListByProvider returns every mapping for the named provider.
+	// Order: group_name ASC for stable GUI rendering.
+	ListByProvider(ctx context.Context, providerID string) ([]*oidcdomain.GroupRoleMapping, error)
+
+	// Get returns one mapping by id. ErrGroupRoleMappingNotFound on miss.
+	Get(ctx context.Context, id string) (*oidcdomain.GroupRoleMapping, error)
+
+	// Add persists a new mapping. Caller MUST have called m.Validate().
+	// Returns ErrGroupRoleMappingDuplicate when the
+	// (provider_id, group_name, role_id) UNIQUE constraint fires.
+	Add(ctx context.Context, m *oidcdomain.GroupRoleMapping) error
+
+	// Remove deletes a mapping by id.
+	Remove(ctx context.Context, id string) error
+
+	// Map resolves an IdP-supplied list of group names against the
+	// provider's mappings. Returns the deduplicated set of role IDs
+	// the user should hold. Empty result means the user matches no
+	// mapping (Phase 3 fail-closed: no session minted, audit row
+	// `auth.oidc_login_unmapped_groups`).
+	Map(ctx context.Context, providerID string, groupNames []string) ([]string, error)
+}
diff --git a/internal/repository/postgres/oidc.go b/internal/repository/postgres/oidc.go
new file mode 100644
index 0000000..9cf08a4
--- /dev/null
+++ b/internal/repository/postgres/oidc.go
@@ -0,0 +1,309 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"github.com/lib/pq"
+
+	oidcdomain "github.com/certctl-io/certctl/internal/auth/oidc/domain"
+	"github.com/certctl-io/certctl/internal/repository"
+)
+
+// =============================================================================
+// OIDCProviderRepository (Auth Bundle 2 Phase 2)
+// =============================================================================
+
+// OIDCProviderRepository is the postgres implementation of
+// repository.OIDCProviderRepository.
+type OIDCProviderRepository struct {
+	db *sql.DB
+}
+
+// NewOIDCProviderRepository constructs an OIDCProviderRepository.
+func NewOIDCProviderRepository(db *sql.DB) *OIDCProviderRepository {
+	return &OIDCProviderRepository{db: db}
+}
+
+const oidcProviderColumns = `id, tenant_id, name, issuer_url, client_id,
+		client_secret_encrypted, redirect_uri, groups_claim_path,
+		groups_claim_format, fetch_userinfo, scopes,
+		allowed_email_domains, iat_window_seconds,
+		jwks_cache_ttl_seconds, created_at, updated_at`
+
+func scanOIDCProvider(row interface{ Scan(...interface{}) error }) (*oidcdomain.OIDCProvider, error) {
+	var p oidcdomain.OIDCProvider
+	var scopes, domains pq.StringArray
+	if err := row.Scan(
+		&p.ID, &p.TenantID, &p.Name, &p.IssuerURL, &p.ClientID,
+		&p.ClientSecretEncrypted, &p.RedirectURI, &p.GroupsClaimPath,
+		&p.GroupsClaimFormat, &p.FetchUserinfo, &scopes,
+		&domains, &p.IATWindowSeconds,
+		&p.JWKSCacheTTLSeconds, &p.CreatedAt, &p.UpdatedAt,
+	); err != nil {
+		return nil, err
+	}
+	p.Scopes = []string(scopes)
+	p.AllowedEmailDomains = []string(domains)
+	return &p, nil
+}
+
+// List returns every configured OIDC provider in the tenant, ordered
+// by created_at ASC for stable GUI rendering.
+func (r *OIDCProviderRepository) List(ctx context.Context, tenantID string) ([]*oidcdomain.OIDCProvider, error) {
+	rows, err := r.db.QueryContext(ctx, `SELECT `+oidcProviderColumns+` FROM oidc_providers WHERE tenant_id = $1 ORDER BY created_at ASC`, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("oidc_providers list: %w", err)
+	}
+	defer rows.Close()
+
+	var out []*oidcdomain.OIDCProvider
+	for rows.Next() {
+		p, err := scanOIDCProvider(rows)
+		if err != nil {
+			return nil, fmt.Errorf("oidc_providers scan: %w", err)
+		}
+		out = append(out, p)
+	}
+	if err := rows.Err(); err != nil {
+		return nil, err
+	}
+	return out, nil
+}
+
+// Get returns one provider by id. ErrOIDCProviderNotFound on miss.
+func (r *OIDCProviderRepository) Get(ctx context.Context, id string) (*oidcdomain.OIDCProvider, error) {
+	row := r.db.QueryRowContext(ctx, `SELECT `+oidcProviderColumns+` FROM oidc_providers WHERE id = $1`, id)
+	p, err := scanOIDCProvider(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrOIDCProviderNotFound
+		}
+		return nil, fmt.Errorf("oidc_providers get: %w", err)
+	}
+	return p, nil
+}
+
+// GetByName returns one provider by (tenant_id, name).
+func (r *OIDCProviderRepository) GetByName(ctx context.Context, tenantID, name string) (*oidcdomain.OIDCProvider, error) {
+	row := r.db.QueryRowContext(ctx, `SELECT `+oidcProviderColumns+` FROM oidc_providers WHERE tenant_id = $1 AND name = $2`, tenantID, name)
+	p, err := scanOIDCProvider(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrOIDCProviderNotFound
+		}
+		return nil, fmt.Errorf("oidc_providers get_by_name: %w", err)
+	}
+	return p, nil
+}
+
+// Create persists a new provider. Caller MUST have called p.Validate()
+// and encrypted ClientSecretEncrypted via internal/crypto/encryption.go.
+// Translates SQLSTATE 23505 (unique_violation) to
+// ErrOIDCProviderDuplicateName.
+func (r *OIDCProviderRepository) Create(ctx context.Context, p *oidcdomain.OIDCProvider) error {
+	_, err := r.db.ExecContext(ctx, `
+		INSERT INTO oidc_providers (
+			id, tenant_id, name, issuer_url, client_id,
+			client_secret_encrypted, redirect_uri, groups_claim_path,
+			groups_claim_format, fetch_userinfo, scopes,
+			allowed_email_domains, iat_window_seconds,
+			jwks_cache_ttl_seconds
+		) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13,$14)`,
+		p.ID, p.TenantID, p.Name, p.IssuerURL, p.ClientID,
+		p.ClientSecretEncrypted, p.RedirectURI, p.GroupsClaimPath,
+		p.GroupsClaimFormat, p.FetchUserinfo, pq.StringArray(p.Scopes),
+		pq.StringArray(p.AllowedEmailDomains), p.IATWindowSeconds,
+		p.JWKSCacheTTLSeconds,
+	)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23505" {
+			return repository.ErrOIDCProviderDuplicateName
+		}
+		return fmt.Errorf("oidc_providers create: %w", err)
+	}
+	return nil
+}
+
+// Update writes the mutable fields back. Immutable: id, tenant_id,
+// created_at. updated_at = NOW().
+func (r *OIDCProviderRepository) Update(ctx context.Context, p *oidcdomain.OIDCProvider) error {
+	res, err := r.db.ExecContext(ctx, `
+		UPDATE oidc_providers SET
+			name = $2,
+			issuer_url = $3,
+			client_id = $4,
+			client_secret_encrypted = $5,
+			redirect_uri = $6,
+			groups_claim_path = $7,
+			groups_claim_format = $8,
+			fetch_userinfo = $9,
+			scopes = $10,
+			allowed_email_domains = $11,
+			iat_window_seconds = $12,
+			jwks_cache_ttl_seconds = $13,
+			updated_at = NOW()
+		WHERE id = $1`,
+		p.ID, p.Name, p.IssuerURL, p.ClientID,
+		p.ClientSecretEncrypted, p.RedirectURI, p.GroupsClaimPath,
+		p.GroupsClaimFormat, p.FetchUserinfo, pq.StringArray(p.Scopes),
+		pq.StringArray(p.AllowedEmailDomains), p.IATWindowSeconds,
+		p.JWKSCacheTTLSeconds,
+	)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23505" {
+			return repository.ErrOIDCProviderDuplicateName
+		}
+		return fmt.Errorf("oidc_providers update: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrOIDCProviderNotFound
+	}
+	return nil
+}
+
+// Delete removes a provider by id. Returns ErrOIDCProviderInUse on
+// SQLSTATE 23503 (foreign_key_violation) — the users table's FK ON
+// DELETE RESTRICT fires when authenticated users still reference
+// this provider.
+func (r *OIDCProviderRepository) Delete(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx, `DELETE FROM oidc_providers WHERE id = $1`, id)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23503" {
+			return repository.ErrOIDCProviderInUse
+		}
+		return fmt.Errorf("oidc_providers delete: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrOIDCProviderNotFound
+	}
+	return nil
+}
+
+// =============================================================================
+// GroupRoleMappingRepository (Auth Bundle 2 Phase 2)
+// =============================================================================
+
+// GroupRoleMappingRepository is the postgres implementation of
+// repository.GroupRoleMappingRepository.
+type GroupRoleMappingRepository struct {
+	db *sql.DB
+}
+
+// NewGroupRoleMappingRepository constructs a GroupRoleMappingRepository.
+func NewGroupRoleMappingRepository(db *sql.DB) *GroupRoleMappingRepository {
+	return &GroupRoleMappingRepository{db: db}
+}
+
+func scanGroupRoleMapping(row interface{ Scan(...interface{}) error }) (*oidcdomain.GroupRoleMapping, error) {
+	var m oidcdomain.GroupRoleMapping
+	if err := row.Scan(&m.ID, &m.TenantID, &m.ProviderID, &m.GroupName, &m.RoleID, &m.CreatedAt); err != nil {
+		return nil, err
+	}
+	return &m, nil
+}
+
+// ListByProvider returns every mapping for the named provider, ordered
+// group_name ASC.
+func (r *GroupRoleMappingRepository) ListByProvider(ctx context.Context, providerID string) ([]*oidcdomain.GroupRoleMapping, error) {
+	rows, err := r.db.QueryContext(ctx, `
+		SELECT id, tenant_id, provider_id, group_name, role_id, created_at
+		FROM group_role_mappings
+		WHERE provider_id = $1
+		ORDER BY group_name ASC`, providerID)
+	if err != nil {
+		return nil, fmt.Errorf("group_role_mappings list_by_provider: %w", err)
+	}
+	defer rows.Close()
+
+	var out []*oidcdomain.GroupRoleMapping
+	for rows.Next() {
+		m, err := scanGroupRoleMapping(rows)
+		if err != nil {
+			return nil, fmt.Errorf("group_role_mappings scan: %w", err)
+		}
+		out = append(out, m)
+	}
+	return out, rows.Err()
+}
+
+// Get returns one mapping by id.
+func (r *GroupRoleMappingRepository) Get(ctx context.Context, id string) (*oidcdomain.GroupRoleMapping, error) {
+	row := r.db.QueryRowContext(ctx, `
+		SELECT id, tenant_id, provider_id, group_name, role_id, created_at
+		FROM group_role_mappings WHERE id = $1`, id)
+	m, err := scanGroupRoleMapping(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrGroupRoleMappingNotFound
+		}
+		return nil, fmt.Errorf("group_role_mappings get: %w", err)
+	}
+	return m, nil
+}
+
+// Add persists a new mapping. Translates SQLSTATE 23505 into
+// ErrGroupRoleMappingDuplicate.
+func (r *GroupRoleMappingRepository) Add(ctx context.Context, m *oidcdomain.GroupRoleMapping) error {
+	_, err := r.db.ExecContext(ctx, `
+		INSERT INTO group_role_mappings (id, tenant_id, provider_id, group_name, role_id)
+		VALUES ($1, $2, $3, $4, $5)`,
+		m.ID, m.TenantID, m.ProviderID, m.GroupName, m.RoleID)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23505" {
+			return repository.ErrGroupRoleMappingDuplicate
+		}
+		return fmt.Errorf("group_role_mappings add: %w", err)
+	}
+	return nil
+}
+
+// Remove deletes a mapping by id.
+func (r *GroupRoleMappingRepository) Remove(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx, `DELETE FROM group_role_mappings WHERE id = $1`, id)
+	if err != nil {
+		return fmt.Errorf("group_role_mappings remove: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrGroupRoleMappingNotFound
+	}
+	return nil
+}
+
+// Map resolves IdP-supplied group names against the provider's
+// mappings. Returns the deduplicated set of role IDs the user should
+// hold. Empty group_names slice yields empty result; empty result
+// means fail-closed (no roles, Phase 3 declines to mint a session).
+func (r *GroupRoleMappingRepository) Map(ctx context.Context, providerID string, groupNames []string) ([]string, error) {
+	if len(groupNames) == 0 {
+		return nil, nil
+	}
+	rows, err := r.db.QueryContext(ctx, `
+		SELECT DISTINCT role_id
+		FROM group_role_mappings
+		WHERE provider_id = $1 AND group_name = ANY($2)`,
+		providerID, pq.StringArray(groupNames))
+	if err != nil {
+		return nil, fmt.Errorf("group_role_mappings map: %w", err)
+	}
+	defer rows.Close()
+
+	var out []string
+	for rows.Next() {
+		var roleID string
+		if err := rows.Scan(&roleID); err != nil {
+			return nil, fmt.Errorf("group_role_mappings map scan: %w", err)
+		}
+		out = append(out, roleID)
+	}
+	return out, rows.Err()
+}
diff --git a/internal/repository/postgres/oidc_test.go b/internal/repository/postgres/oidc_test.go
new file mode 100644
index 0000000..427d176
--- /dev/null
+++ b/internal/repository/postgres/oidc_test.go
@@ -0,0 +1,366 @@
+package postgres_test
+
+import (
+	"context"
+	"errors"
+	"testing"
+	"time"
+
+	oidcdomain "github.com/certctl-io/certctl/internal/auth/oidc/domain"
+	"github.com/certctl-io/certctl/internal/repository"
+	"github.com/certctl-io/certctl/internal/repository/postgres"
+)
+
+// =============================================================================
+// OIDCProviderRepository tests (Auth Bundle 2 Phase 2)
+//
+// Schema-per-test isolation via getTestDB().freshSchema(t). Run with:
+//
+//   go test -count=1 ./internal/repository/postgres/...
+//
+// (omit -short; testing.Short() skips all integration tests.)
+// =============================================================================
+
+func newValidProvider(suffix string) *oidcdomain.OIDCProvider {
+	return &oidcdomain.OIDCProvider{
+		ID:                    "op-" + suffix,
+		TenantID:              "t-default",
+		Name:                  "Provider " + suffix,
+		IssuerURL:             "https://idp." + suffix + ".example.com",
+		ClientID:              "certctl",
+		ClientSecretEncrypted: []byte{0x02, 0x00, 0x01, 0x02, 0x03},
+		RedirectURI:           "https://certctl.example.com/auth/oidc/callback",
+		GroupsClaimPath:       "groups",
+		GroupsClaimFormat:     "string-array",
+		Scopes:                []string{"openid", "profile", "email"},
+		AllowedEmailDomains:   []string{},
+		IATWindowSeconds:      300,
+		JWKSCacheTTLSeconds:   3600,
+	}
+}
+
+func TestOIDCProviderRepository_CreateAndGet(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("a")
+	if err := repo.Create(ctx, p); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+
+	got, err := repo.Get(ctx, p.ID)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if got.Name != p.Name {
+		t.Errorf("Name roundtrip: got %q, want %q", got.Name, p.Name)
+	}
+	if got.IssuerURL != p.IssuerURL {
+		t.Errorf("IssuerURL roundtrip mismatch")
+	}
+	// Defaults from the migration kicked in for any unset bool / array.
+	if got.FetchUserinfo != false {
+		t.Errorf("FetchUserinfo default = %v; want false", got.FetchUserinfo)
+	}
+	if len(got.Scopes) != 3 {
+		t.Errorf("Scopes roundtrip count = %d; want 3", len(got.Scopes))
+	}
+	// Defense: client_secret_encrypted column must NOT contain plaintext.
+	// Since we wrote a v2 magic-byte stub, the byte stream comes back as-is.
+	if len(got.ClientSecretEncrypted) == 0 {
+		t.Errorf("ClientSecretEncrypted lost on roundtrip")
+	}
+}
+
+func TestOIDCProviderRepository_GetNotFound(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	_, err := repo.Get(ctx, "op-nonexistent")
+	if !errors.Is(err, repository.ErrOIDCProviderNotFound) {
+		t.Errorf("err = %v; want ErrOIDCProviderNotFound", err)
+	}
+}
+
+func TestOIDCProviderRepository_DuplicateName(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	p1 := newValidProvider("dup1")
+	if err := repo.Create(ctx, p1); err != nil {
+		t.Fatalf("Create p1: %v", err)
+	}
+
+	p2 := newValidProvider("dup2")
+	p2.Name = p1.Name // collision on (tenant_id, name)
+	err := repo.Create(ctx, p2)
+	if !errors.Is(err, repository.ErrOIDCProviderDuplicateName) {
+		t.Errorf("Create with duplicate name err = %v; want ErrOIDCProviderDuplicateName", err)
+	}
+}
+
+func TestOIDCProviderRepository_List(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	for _, suf := range []string{"x", "y", "z"} {
+		if err := repo.Create(ctx, newValidProvider(suf)); err != nil {
+			t.Fatalf("Create %q: %v", suf, err)
+		}
+	}
+
+	out, err := repo.List(ctx, "t-default")
+	if err != nil {
+		t.Fatalf("List: %v", err)
+	}
+	if len(out) != 3 {
+		t.Errorf("List count = %d; want 3", len(out))
+	}
+}
+
+func TestOIDCProviderRepository_Update(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("upd")
+	if err := repo.Create(ctx, p); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+
+	p.Name = "Renamed"
+	p.FetchUserinfo = true
+	if err := repo.Update(ctx, p); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+
+	got, err := repo.Get(ctx, p.ID)
+	if err != nil {
+		t.Fatalf("Get post-update: %v", err)
+	}
+	if got.Name != "Renamed" {
+		t.Errorf("Update did not persist Name; got %q", got.Name)
+	}
+	if !got.FetchUserinfo {
+		t.Errorf("Update did not persist FetchUserinfo")
+	}
+}
+
+func TestOIDCProviderRepository_DeleteNotFound(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	err := repo.Delete(ctx, "op-nonexistent")
+	if !errors.Is(err, repository.ErrOIDCProviderNotFound) {
+		t.Errorf("err = %v; want ErrOIDCProviderNotFound", err)
+	}
+}
+
+func TestOIDCProviderRepository_DeleteSucceedsWhenNoUsersReference(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewOIDCProviderRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("del")
+	if err := repo.Create(ctx, p); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+	if err := repo.Delete(ctx, p.ID); err != nil {
+		t.Fatalf("Delete: %v", err)
+	}
+	_, err := repo.Get(ctx, p.ID)
+	if !errors.Is(err, repository.ErrOIDCProviderNotFound) {
+		t.Errorf("post-delete Get err = %v; want ErrOIDCProviderNotFound", err)
+	}
+}
+
+// TestOIDCProviderRepository_DeleteRefusedWhenUsersReference pins the
+// FK ON DELETE RESTRICT translation. With at least one users row
+// referencing the provider, Delete must return ErrOIDCProviderInUse.
+func TestOIDCProviderRepository_DeleteRefusedWhenUsersReference(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("inuse")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	u := &struct{ ID string }{ID: "u-test"}
+	_ = u
+	user := newValidUser("inuse", p.ID)
+	if err := userRepo.Create(ctx, user); err != nil {
+		t.Fatalf("Create user: %v", err)
+	}
+
+	err := providerRepo.Delete(ctx, p.ID)
+	if !errors.Is(err, repository.ErrOIDCProviderInUse) {
+		t.Errorf("Delete with referencing user err = %v; want ErrOIDCProviderInUse", err)
+	}
+}
+
+// =============================================================================
+// GroupRoleMappingRepository
+// =============================================================================
+
+func TestGroupRoleMappingRepository_AddListMap(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	mappingRepo := postgres.NewGroupRoleMappingRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("grm")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+
+	mappings := []*oidcdomain.GroupRoleMapping{
+		{ID: "grm-1", TenantID: "t-default", ProviderID: p.ID, GroupName: "engineers", RoleID: "r-operator"},
+		{ID: "grm-2", TenantID: "t-default", ProviderID: p.ID, GroupName: "platform-admins", RoleID: "r-admin"},
+		{ID: "grm-3", TenantID: "t-default", ProviderID: p.ID, GroupName: "compliance", RoleID: "r-auditor"},
+	}
+	for _, m := range mappings {
+		if err := mappingRepo.Add(ctx, m); err != nil {
+			t.Fatalf("Add %s: %v", m.GroupName, err)
+		}
+	}
+
+	listed, err := mappingRepo.ListByProvider(ctx, p.ID)
+	if err != nil {
+		t.Fatalf("ListByProvider: %v", err)
+	}
+	if len(listed) != 3 {
+		t.Errorf("ListByProvider count = %d; want 3", len(listed))
+	}
+
+	// Map: user has groups [engineers, marketing]. Marketing has no
+	// mapping; only engineers maps to r-operator.
+	roleIDs, err := mappingRepo.Map(ctx, p.ID, []string{"engineers", "marketing"})
+	if err != nil {
+		t.Fatalf("Map: %v", err)
+	}
+	if len(roleIDs) != 1 || roleIDs[0] != "r-operator" {
+		t.Errorf("Map(engineers, marketing) = %v; want [r-operator]", roleIDs)
+	}
+
+	// Map: user has groups [engineers, platform-admins]. Both map.
+	roleIDs, err = mappingRepo.Map(ctx, p.ID, []string{"engineers", "platform-admins"})
+	if err != nil {
+		t.Fatalf("Map (multi): %v", err)
+	}
+	if len(roleIDs) != 2 {
+		t.Errorf("Map(engineers, platform-admins) count = %d; want 2", len(roleIDs))
+	}
+
+	// Map empty groups: empty result, no error (Phase 3 fail-closes).
+	roleIDs, err = mappingRepo.Map(ctx, p.ID, nil)
+	if err != nil {
+		t.Fatalf("Map(nil): %v", err)
+	}
+	if len(roleIDs) != 0 {
+		t.Errorf("Map(nil) returned %d roles; want 0", len(roleIDs))
+	}
+}
+
+func TestGroupRoleMappingRepository_DuplicateRejected(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	mappingRepo := postgres.NewGroupRoleMappingRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("dup")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	m := &oidcdomain.GroupRoleMapping{
+		ID: "grm-dup-1", TenantID: "t-default", ProviderID: p.ID,
+		GroupName: "engineers", RoleID: "r-operator",
+	}
+	if err := mappingRepo.Add(ctx, m); err != nil {
+		t.Fatalf("Add first: %v", err)
+	}
+	m2 := &oidcdomain.GroupRoleMapping{
+		ID: "grm-dup-2", TenantID: "t-default", ProviderID: p.ID,
+		GroupName: "engineers", RoleID: "r-operator",
+	}
+	err := mappingRepo.Add(ctx, m2)
+	if !errors.Is(err, repository.ErrGroupRoleMappingDuplicate) {
+		t.Errorf("Add duplicate err = %v; want ErrGroupRoleMappingDuplicate", err)
+	}
+}
+
+func TestGroupRoleMappingRepository_ProviderDeleteCascades(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	mappingRepo := postgres.NewGroupRoleMappingRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("cascade")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	for i, group := range []string{"a", "b", "c"} {
+		m := &oidcdomain.GroupRoleMapping{
+			ID: "grm-cas-" + string(rune('a'+i)), TenantID: "t-default",
+			ProviderID: p.ID, GroupName: group, RoleID: "r-viewer",
+		}
+		if err := mappingRepo.Add(ctx, m); err != nil {
+			t.Fatalf("Add %s: %v", group, err)
+		}
+	}
+
+	// Delete provider: ON DELETE CASCADE on group_role_mappings.provider_id
+	// should drop the 3 mappings too.
+	if err := providerRepo.Delete(ctx, p.ID); err != nil {
+		t.Fatalf("Delete provider: %v", err)
+	}
+	listed, err := mappingRepo.ListByProvider(ctx, p.ID)
+	if err != nil {
+		t.Fatalf("ListByProvider post-cascade: %v", err)
+	}
+	if len(listed) != 0 {
+		t.Errorf("CASCADE failed; %d mappings remain", len(listed))
+	}
+}
+
+// quiet unused-import keepalives so single-test runs don't drop them.
+var _ = time.Now
diff --git a/internal/repository/postgres/session.go b/internal/repository/postgres/session.go
new file mode 100644
index 0000000..c6dd503
--- /dev/null
+++ b/internal/repository/postgres/session.go
@@ -0,0 +1,350 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"github.com/lib/pq"
+
+	sessiondomain "github.com/certctl-io/certctl/internal/auth/session/domain"
+	"github.com/certctl-io/certctl/internal/repository"
+)
+
+// =============================================================================
+// SessionRepository (Auth Bundle 2 Phase 2)
+// =============================================================================
+
+// SessionRepository is the postgres implementation of
+// repository.SessionRepository.
+type SessionRepository struct {
+	db *sql.DB
+}
+
+// NewSessionRepository constructs a SessionRepository.
+func NewSessionRepository(db *sql.DB) *SessionRepository {
+	return &SessionRepository{db: db}
+}
+
+const sessionColumns = `id, tenant_id, actor_id, actor_type,
+		signing_key_id, is_pre_login, csrf_token_hash,
+		idle_expires_at, absolute_expires_at, created_at, last_seen_at,
+		ip_address, user_agent, revoked_at`
+
+func scanSession(row interface{ Scan(...interface{}) error }) (*sessiondomain.Session, error) {
+	var s sessiondomain.Session
+	var revokedAt sql.NullTime
+	if err := row.Scan(
+		&s.ID, &s.TenantID, &s.ActorID, &s.ActorType,
+		&s.SigningKeyID, &s.IsPreLogin, &s.CSRFTokenHash,
+		&s.IdleExpiresAt, &s.AbsoluteExpiresAt, &s.CreatedAt, &s.LastSeenAt,
+		&s.IPAddress, &s.UserAgent, &revokedAt,
+	); err != nil {
+		return nil, err
+	}
+	if revokedAt.Valid {
+		s.RevokedAt = &revokedAt.Time
+	}
+	return &s, nil
+}
+
+// Create persists a session row. Caller MUST have called s.Validate().
+func (r *SessionRepository) Create(ctx context.Context, s *sessiondomain.Session) error {
+	_, err := r.db.ExecContext(ctx, `
+		INSERT INTO sessions (
+			id, tenant_id, actor_id, actor_type, signing_key_id,
+			is_pre_login, csrf_token_hash, idle_expires_at,
+			absolute_expires_at, created_at, last_seen_at,
+			ip_address, user_agent
+		) VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12,$13)`,
+		s.ID, s.TenantID, s.ActorID, s.ActorType, s.SigningKeyID,
+		s.IsPreLogin, s.CSRFTokenHash, s.IdleExpiresAt,
+		s.AbsoluteExpiresAt, s.CreatedAt, s.LastSeenAt,
+		s.IPAddress, s.UserAgent)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23505" {
+			return repository.ErrAuthDuplicateName
+		}
+		return fmt.Errorf("sessions create: %w", err)
+	}
+	return nil
+}
+
+// Get returns a session by id. Returns the row even if revoked /
+// expired; the service layer handles the disposition.
+func (r *SessionRepository) Get(ctx context.Context, id string) (*sessiondomain.Session, error) {
+	row := r.db.QueryRowContext(ctx, `SELECT `+sessionColumns+` FROM sessions WHERE id = $1`, id)
+	s, err := scanSession(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrSessionNotFound
+		}
+		return nil, fmt.Errorf("sessions get: %w", err)
+	}
+	return s, nil
+}
+
+// ListByActor returns active (non-revoked, non-expired, non-pre-login)
+// sessions for an actor.
+func (r *SessionRepository) ListByActor(ctx context.Context, actorID, actorType, tenantID string) ([]*sessiondomain.Session, error) {
+	rows, err := r.db.QueryContext(ctx, `
+		SELECT `+sessionColumns+`
+		FROM sessions
+		WHERE actor_id = $1
+		  AND actor_type = $2
+		  AND tenant_id = $3
+		  AND revoked_at IS NULL
+		  AND is_pre_login = FALSE
+		  AND absolute_expires_at > NOW()
+		ORDER BY created_at DESC`,
+		actorID, actorType, tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("sessions list_by_actor: %w", err)
+	}
+	defer rows.Close()
+
+	var out []*sessiondomain.Session
+	for rows.Next() {
+		s, err := scanSession(rows)
+		if err != nil {
+			return nil, fmt.Errorf("sessions scan: %w", err)
+		}
+		out = append(out, s)
+	}
+	return out, rows.Err()
+}
+
+// UpdateLastSeen sets last_seen_at = NOW() for the named session.
+func (r *SessionRepository) UpdateLastSeen(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx, `UPDATE sessions SET last_seen_at = NOW() WHERE id = $1`, id)
+	if err != nil {
+		return fmt.Errorf("sessions update_last_seen: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrSessionNotFound
+	}
+	return nil
+}
+
+// Revoke sets revoked_at = NOW() for the named session. Idempotent:
+// re-revoking an already-revoked session is a no-op (returns nil).
+func (r *SessionRepository) Revoke(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx, `UPDATE sessions SET revoked_at = NOW() WHERE id = $1 AND revoked_at IS NULL`, id)
+	if err != nil {
+		return fmt.Errorf("sessions revoke: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		// Distinguish "not found" from "already revoked" by re-querying.
+		row := r.db.QueryRowContext(ctx, `SELECT 1 FROM sessions WHERE id = $1`, id)
+		var x int
+		if err := row.Scan(&x); err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				return repository.ErrSessionNotFound
+			}
+			return fmt.Errorf("sessions revoke probe: %w", err)
+		}
+		// Row exists but already revoked: idempotent success.
+	}
+	return nil
+}
+
+// RevokeAllForActor sets revoked_at = NOW() on every active session
+// for an actor. Returns nil on zero matches (idempotent).
+func (r *SessionRepository) RevokeAllForActor(ctx context.Context, actorID, actorType, tenantID string) error {
+	_, err := r.db.ExecContext(ctx, `
+		UPDATE sessions SET revoked_at = NOW()
+		WHERE actor_id = $1 AND actor_type = $2 AND tenant_id = $3 AND revoked_at IS NULL`,
+		actorID, actorType, tenantID)
+	if err != nil {
+		return fmt.Errorf("sessions revoke_all_for_actor: %w", err)
+	}
+	return nil
+}
+
+// GarbageCollectExpired deletes:
+//   - Sessions whose absolute_expires_at < NOW() (post-login expired).
+//   - Pre-login sessions older than 10 minutes.
+//
+// Returns the number of rows deleted across both classes.
+func (r *SessionRepository) GarbageCollectExpired(ctx context.Context) (int, error) {
+	res, err := r.db.ExecContext(ctx, `
+		DELETE FROM sessions
+		WHERE absolute_expires_at < NOW()
+		   OR (is_pre_login = TRUE AND created_at < NOW() - INTERVAL '10 minutes')`)
+	if err != nil {
+		return 0, fmt.Errorf("sessions garbage_collect: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	return int(n), nil
+}
+
+// Delete unconditionally removes a session row.
+func (r *SessionRepository) Delete(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx, `DELETE FROM sessions WHERE id = $1`, id)
+	if err != nil {
+		return fmt.Errorf("sessions delete: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrSessionNotFound
+	}
+	return nil
+}
+
+// =============================================================================
+// SessionSigningKeyRepository (Auth Bundle 2 Phase 2)
+// =============================================================================
+
+// SessionSigningKeyRepository is the postgres implementation of
+// repository.SessionSigningKeyRepository.
+type SessionSigningKeyRepository struct {
+	db *sql.DB
+}
+
+// NewSessionSigningKeyRepository constructs a SessionSigningKeyRepository.
+func NewSessionSigningKeyRepository(db *sql.DB) *SessionSigningKeyRepository {
+	return &SessionSigningKeyRepository{db: db}
+}
+
+const sessionSigningKeyColumns = `id, tenant_id, key_material_encrypted, created_at, retired_at`
+
+func scanSessionSigningKey(row interface{ Scan(...interface{}) error }) (*sessiondomain.SessionSigningKey, error) {
+	var k sessiondomain.SessionSigningKey
+	var retiredAt sql.NullTime
+	if err := row.Scan(&k.ID, &k.TenantID, &k.KeyMaterialEncrypted, &k.CreatedAt, &retiredAt); err != nil {
+		return nil, err
+	}
+	if retiredAt.Valid {
+		k.RetiredAt = &retiredAt.Time
+	}
+	return &k, nil
+}
+
+// List returns every signing key in the tenant, including retired ones.
+func (r *SessionSigningKeyRepository) List(ctx context.Context, tenantID string) ([]*sessiondomain.SessionSigningKey, error) {
+	rows, err := r.db.QueryContext(ctx,
+		`SELECT `+sessionSigningKeyColumns+` FROM session_signing_keys WHERE tenant_id = $1 ORDER BY created_at DESC`,
+		tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("session_signing_keys list: %w", err)
+	}
+	defer rows.Close()
+
+	var out []*sessiondomain.SessionSigningKey
+	for rows.Next() {
+		k, err := scanSessionSigningKey(rows)
+		if err != nil {
+			return nil, fmt.Errorf("session_signing_keys scan: %w", err)
+		}
+		out = append(out, k)
+	}
+	return out, rows.Err()
+}
+
+// GetActive returns the most-recently-created non-retired key. Returns
+// ErrSessionSigningKeyNotFound when no non-retired key exists.
+func (r *SessionSigningKeyRepository) GetActive(ctx context.Context, tenantID string) (*sessiondomain.SessionSigningKey, error) {
+	row := r.db.QueryRowContext(ctx, `
+		SELECT `+sessionSigningKeyColumns+`
+		FROM session_signing_keys
+		WHERE tenant_id = $1 AND retired_at IS NULL
+		ORDER BY created_at DESC
+		LIMIT 1`, tenantID)
+	k, err := scanSessionSigningKey(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrSessionSigningKeyNotFound
+		}
+		return nil, fmt.Errorf("session_signing_keys get_active: %w", err)
+	}
+	return k, nil
+}
+
+// Get returns a key by id (including retired keys; Phase 4's Validate
+// consults this for cookies signed under retired-but-in-retention keys).
+func (r *SessionSigningKeyRepository) Get(ctx context.Context, id string) (*sessiondomain.SessionSigningKey, error) {
+	row := r.db.QueryRowContext(ctx,
+		`SELECT `+sessionSigningKeyColumns+` FROM session_signing_keys WHERE id = $1`, id)
+	k, err := scanSessionSigningKey(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrSessionSigningKeyNotFound
+		}
+		return nil, fmt.Errorf("session_signing_keys get: %w", err)
+	}
+	return k, nil
+}
+
+// Add persists a new signing key. Caller MUST have called k.Validate().
+func (r *SessionSigningKeyRepository) Add(ctx context.Context, k *sessiondomain.SessionSigningKey) error {
+	if k.CreatedAt.IsZero() {
+		_, err := r.db.ExecContext(ctx, `
+			INSERT INTO session_signing_keys (id, tenant_id, key_material_encrypted)
+			VALUES ($1, $2, $3)`,
+			k.ID, k.TenantID, k.KeyMaterialEncrypted)
+		if err != nil {
+			return fmt.Errorf("session_signing_keys add: %w", err)
+		}
+		// Read the row back to populate CreatedAt.
+		row := r.db.QueryRowContext(ctx, `SELECT created_at FROM session_signing_keys WHERE id = $1`, k.ID)
+		if err := row.Scan(&k.CreatedAt); err != nil {
+			return fmt.Errorf("session_signing_keys add (read created_at): %w", err)
+		}
+		return nil
+	}
+	_, err := r.db.ExecContext(ctx, `
+		INSERT INTO session_signing_keys (id, tenant_id, key_material_encrypted, created_at)
+		VALUES ($1, $2, $3, $4)`,
+		k.ID, k.TenantID, k.KeyMaterialEncrypted, k.CreatedAt)
+	if err != nil {
+		return fmt.Errorf("session_signing_keys add: %w", err)
+	}
+	return nil
+}
+
+// Retire marks an active key as retired (sets retired_at = NOW()).
+// Idempotent: re-retiring an already-retired key is a no-op.
+func (r *SessionSigningKeyRepository) Retire(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx,
+		`UPDATE session_signing_keys SET retired_at = NOW() WHERE id = $1 AND retired_at IS NULL`, id)
+	if err != nil {
+		return fmt.Errorf("session_signing_keys retire: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		// Distinguish not-found vs already-retired.
+		row := r.db.QueryRowContext(ctx, `SELECT 1 FROM session_signing_keys WHERE id = $1`, id)
+		var x int
+		if err := row.Scan(&x); err != nil {
+			if errors.Is(err, sql.ErrNoRows) {
+				return repository.ErrSessionSigningKeyNotFound
+			}
+			return fmt.Errorf("session_signing_keys retire probe: %w", err)
+		}
+		// Row exists but already retired: idempotent success.
+	}
+	return nil
+}
+
+// Delete unconditionally removes a signing key. Returns
+// ErrSessionSigningKeyInUse on SQLSTATE 23503 (FK ON DELETE RESTRICT
+// from sessions.signing_key_id).
+func (r *SessionSigningKeyRepository) Delete(ctx context.Context, id string) error {
+	res, err := r.db.ExecContext(ctx, `DELETE FROM session_signing_keys WHERE id = $1`, id)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23503" {
+			return repository.ErrSessionSigningKeyInUse
+		}
+		return fmt.Errorf("session_signing_keys delete: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrSessionSigningKeyNotFound
+	}
+	return nil
+}
diff --git a/internal/repository/postgres/session_test.go b/internal/repository/postgres/session_test.go
new file mode 100644
index 0000000..57625c7
--- /dev/null
+++ b/internal/repository/postgres/session_test.go
@@ -0,0 +1,431 @@
+package postgres_test
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+	"time"
+
+	sessiondomain "github.com/certctl-io/certctl/internal/auth/session/domain"
+	"github.com/certctl-io/certctl/internal/repository"
+	"github.com/certctl-io/certctl/internal/repository/postgres"
+)
+
+// =============================================================================
+// SessionSigningKey tests
+// =============================================================================
+
+func newValidSigningKey(suffix string) *sessiondomain.SessionSigningKey {
+	return &sessiondomain.SessionSigningKey{
+		ID:                   "sk-" + suffix,
+		TenantID:             "t-default",
+		KeyMaterialEncrypted: []byte{0x02, 0x00, 0x01, 0x02, 0x03},
+	}
+}
+
+func TestSessionSigningKeyRepository_AddAndGetActive(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewSessionSigningKeyRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("a")
+	if err := repo.Add(ctx, k); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+	if k.CreatedAt.IsZero() {
+		t.Errorf("Add did not populate CreatedAt")
+	}
+
+	got, err := repo.GetActive(ctx, "t-default")
+	if err != nil {
+		t.Fatalf("GetActive: %v", err)
+	}
+	if got.ID != k.ID {
+		t.Errorf("GetActive returned %q; want %q", got.ID, k.ID)
+	}
+}
+
+func TestSessionSigningKeyRepository_GetActiveSkipsRetired(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewSessionSigningKeyRepository(db)
+	ctx := context.Background()
+
+	// Add older key, retire it. Add newer key. GetActive must return newer.
+	older := newValidSigningKey("older")
+	if err := repo.Add(ctx, older); err != nil {
+		t.Fatalf("Add older: %v", err)
+	}
+	if err := repo.Retire(ctx, older.ID); err != nil {
+		t.Fatalf("Retire older: %v", err)
+	}
+	// Sleep a millisecond so created_at orders deterministically.
+	time.Sleep(10 * time.Millisecond)
+	newer := newValidSigningKey("newer")
+	if err := repo.Add(ctx, newer); err != nil {
+		t.Fatalf("Add newer: %v", err)
+	}
+
+	got, err := repo.GetActive(ctx, "t-default")
+	if err != nil {
+		t.Fatalf("GetActive: %v", err)
+	}
+	if got.ID != newer.ID {
+		t.Errorf("GetActive returned %q; want %q (older was retired)", got.ID, newer.ID)
+	}
+}
+
+func TestSessionSigningKeyRepository_GetActiveReturnsNotFound(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewSessionSigningKeyRepository(db)
+	ctx := context.Background()
+
+	_, err := repo.GetActive(ctx, "t-default")
+	if !errors.Is(err, repository.ErrSessionSigningKeyNotFound) {
+		t.Errorf("err = %v; want ErrSessionSigningKeyNotFound", err)
+	}
+}
+
+func TestSessionSigningKeyRepository_RetireIsIdempotent(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewSessionSigningKeyRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("retire")
+	if err := repo.Add(ctx, k); err != nil {
+		t.Fatalf("Add: %v", err)
+	}
+	if err := repo.Retire(ctx, k.ID); err != nil {
+		t.Fatalf("first Retire: %v", err)
+	}
+	if err := repo.Retire(ctx, k.ID); err != nil {
+		t.Errorf("second Retire (already retired) should be idempotent; got %v", err)
+	}
+}
+
+func TestSessionSigningKeyRepository_DeleteRefusedWhenSessionsReference(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("inuse")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+	s := newValidSession("s1", k.ID)
+	if err := sessRepo.Create(ctx, s); err != nil {
+		t.Fatalf("Create session: %v", err)
+	}
+
+	err := keyRepo.Delete(ctx, k.ID)
+	if !errors.Is(err, repository.ErrSessionSigningKeyInUse) {
+		t.Errorf("Delete with referencing session err = %v; want ErrSessionSigningKeyInUse", err)
+	}
+}
+
+// =============================================================================
+// Session tests
+// =============================================================================
+
+func newValidSession(suffix, signingKeyID string) *sessiondomain.Session {
+	now := time.Now().UTC().Truncate(time.Microsecond)
+	return &sessiondomain.Session{
+		ID:                "ses-" + suffix,
+		TenantID:          "t-default",
+		ActorID:           "u-" + suffix,
+		ActorType:         "User",
+		SigningKeyID:      signingKeyID,
+		IsPreLogin:        false,
+		CSRFTokenHash:     strings.Repeat("a", 64),
+		IdleExpiresAt:     now.Add(time.Hour),
+		AbsoluteExpiresAt: now.Add(8 * time.Hour),
+		CreatedAt:         now,
+		LastSeenAt:        now,
+		IPAddress:         "10.0.0.1",
+		UserAgent:         "Mozilla/5.0",
+	}
+}
+
+func TestSessionRepository_CreateAndGet(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("k1")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+	s := newValidSession("s1", k.ID)
+	if err := sessRepo.Create(ctx, s); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+
+	got, err := sessRepo.Get(ctx, s.ID)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if got.ActorID != s.ActorID {
+		t.Errorf("ActorID roundtrip mismatch")
+	}
+	if got.RevokedAt != nil {
+		t.Errorf("RevokedAt should be nil on fresh session")
+	}
+}
+
+func TestSessionRepository_GetNotFound(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	_, err := repo.Get(ctx, "ses-nonexistent")
+	if !errors.Is(err, repository.ErrSessionNotFound) {
+		t.Errorf("err = %v; want ErrSessionNotFound", err)
+	}
+}
+
+func TestSessionRepository_RevokeAndGet(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("k2")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+	s := newValidSession("s2", k.ID)
+	if err := sessRepo.Create(ctx, s); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+
+	if err := sessRepo.Revoke(ctx, s.ID); err != nil {
+		t.Fatalf("Revoke: %v", err)
+	}
+	got, err := sessRepo.Get(ctx, s.ID)
+	if err != nil {
+		t.Fatalf("Get post-revoke: %v", err)
+	}
+	if got.RevokedAt == nil {
+		t.Errorf("RevokedAt nil after Revoke")
+	}
+
+	// Idempotent re-revoke: returns nil, no panic, no double-update.
+	if err := sessRepo.Revoke(ctx, s.ID); err != nil {
+		t.Errorf("re-Revoke (idempotent) err = %v; want nil", err)
+	}
+}
+
+func TestSessionRepository_RevokeNotFound(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	if err := repo.Revoke(ctx, "ses-nonexistent"); !errors.Is(err, repository.ErrSessionNotFound) {
+		t.Errorf("err = %v; want ErrSessionNotFound", err)
+	}
+}
+
+func TestSessionRepository_ListByActorActiveOnly(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("la")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+	// 3 active + 1 revoked + 1 pre-login.
+	for i, suf := range []string{"a1", "a2", "a3"} {
+		s := newValidSession(suf, k.ID)
+		s.ActorID = "u-list-actor"
+		// uniqueness: stagger created_at so list ordering is stable
+		s.CreatedAt = s.CreatedAt.Add(time.Duration(i) * time.Millisecond)
+		if err := sessRepo.Create(ctx, s); err != nil {
+			t.Fatalf("Create %s: %v", suf, err)
+		}
+	}
+	revoked := newValidSession("rev", k.ID)
+	revoked.ActorID = "u-list-actor"
+	if err := sessRepo.Create(ctx, revoked); err != nil {
+		t.Fatalf("Create revoked: %v", err)
+	}
+	if err := sessRepo.Revoke(ctx, revoked.ID); err != nil {
+		t.Fatalf("Revoke: %v", err)
+	}
+	preLogin := newValidSession("pre", k.ID)
+	preLogin.ActorID = "u-list-actor"
+	preLogin.IsPreLogin = true
+	preLogin.CSRFTokenHash = "" // pre-login rows have no CSRF token
+	if err := sessRepo.Create(ctx, preLogin); err != nil {
+		t.Fatalf("Create pre-login: %v", err)
+	}
+
+	out, err := sessRepo.ListByActor(ctx, "u-list-actor", "User", "t-default")
+	if err != nil {
+		t.Fatalf("ListByActor: %v", err)
+	}
+	if len(out) != 3 {
+		t.Errorf("ListByActor count = %d; want 3 (revoked + pre-login excluded)", len(out))
+	}
+}
+
+func TestSessionRepository_RevokeAllForActor(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("ra")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+	// 3 sessions for one actor.
+	for _, suf := range []string{"r1", "r2", "r3"} {
+		s := newValidSession(suf, k.ID)
+		s.ActorID = "u-fired"
+		if err := sessRepo.Create(ctx, s); err != nil {
+			t.Fatalf("Create %s: %v", suf, err)
+		}
+	}
+	if err := sessRepo.RevokeAllForActor(ctx, "u-fired", "User", "t-default"); err != nil {
+		t.Fatalf("RevokeAllForActor: %v", err)
+	}
+	out, err := sessRepo.ListByActor(ctx, "u-fired", "User", "t-default")
+	if err != nil {
+		t.Fatalf("ListByActor post-revoke: %v", err)
+	}
+	if len(out) != 0 {
+		t.Errorf("RevokeAllForActor left %d sessions active; want 0", len(out))
+	}
+}
+
+func TestSessionRepository_GarbageCollectExpired(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("gc")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+
+	// One session with absolute expiry in the past (write directly via SQL
+	// to bypass the CHECK constraints; this simulates a row that aged
+	// past expiry without GC having run yet).
+	now := time.Now().UTC()
+	old := time.Now().UTC().Add(-2 * time.Hour)
+	older := time.Now().UTC().Add(-3 * time.Hour)
+	_, err := db.ExecContext(ctx, `
+		INSERT INTO sessions (id, tenant_id, actor_id, actor_type, signing_key_id,
+			is_pre_login, csrf_token_hash, idle_expires_at, absolute_expires_at,
+			created_at, last_seen_at, ip_address, user_agent)
+		VALUES ($1, 't-default', 'u-gc', 'User', $2, FALSE, '',
+			$3, $4, $5, $5, '', '')`,
+		"ses-expired", k.ID, older, old, time.Now().UTC().Add(-4*time.Hour))
+	if err != nil {
+		t.Fatalf("seed expired: %v", err)
+	}
+
+	// One pre-login row older than 10 minutes.
+	_, err = db.ExecContext(ctx, `
+		INSERT INTO sessions (id, tenant_id, actor_id, actor_type, signing_key_id,
+			is_pre_login, csrf_token_hash, idle_expires_at, absolute_expires_at,
+			created_at, last_seen_at, ip_address, user_agent)
+		VALUES ($1, 't-default', 'u-gc', 'User', $2, TRUE, '',
+			$3, $4, $5, $5, '', '')`,
+		"ses-prelogin-old", k.ID,
+		now.Add(-15*time.Minute).Add(time.Hour),   // idle in future relative to created
+		now.Add(-15*time.Minute).Add(2*time.Hour), // absolute > idle, both > created
+		now.Add(-15*time.Minute))                  // created 15 min ago (older than 10 min TTL)
+	if err != nil {
+		t.Fatalf("seed pre-login: %v", err)
+	}
+
+	// One active session (NOT to be GC'd).
+	active := newValidSession("active", k.ID)
+	active.ActorID = "u-gc"
+	if err := sessRepo.Create(ctx, active); err != nil {
+		t.Fatalf("seed active: %v", err)
+	}
+
+	n, err := sessRepo.GarbageCollectExpired(ctx)
+	if err != nil {
+		t.Fatalf("GC: %v", err)
+	}
+	if n != 2 {
+		t.Errorf("GC deleted %d rows; want 2 (expired + old pre-login)", n)
+	}
+
+	// Active session survives.
+	if _, err := sessRepo.Get(ctx, active.ID); err != nil {
+		t.Errorf("active session should survive GC; got %v", err)
+	}
+}
+
+func TestSessionRepository_UpdateLastSeen(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	keyRepo := postgres.NewSessionSigningKeyRepository(db)
+	sessRepo := postgres.NewSessionRepository(db)
+	ctx := context.Background()
+
+	k := newValidSigningKey("uls")
+	if err := keyRepo.Add(ctx, k); err != nil {
+		t.Fatalf("Add key: %v", err)
+	}
+	s := newValidSession("uls", k.ID)
+	if err := sessRepo.Create(ctx, s); err != nil {
+		t.Fatalf("Create: %v", err)
+	}
+	originalSeen := s.LastSeenAt
+	time.Sleep(10 * time.Millisecond)
+	if err := sessRepo.UpdateLastSeen(ctx, s.ID); err != nil {
+		t.Fatalf("UpdateLastSeen: %v", err)
+	}
+	got, _ := sessRepo.Get(ctx, s.ID)
+	if !got.LastSeenAt.After(originalSeen) {
+		t.Errorf("LastSeenAt did not advance after UpdateLastSeen")
+	}
+}
diff --git a/internal/repository/postgres/user.go b/internal/repository/postgres/user.go
new file mode 100644
index 0000000..95a9ad2
--- /dev/null
+++ b/internal/repository/postgres/user.go
@@ -0,0 +1,137 @@
+package postgres
+
+import (
+	"context"
+	"database/sql"
+	"errors"
+	"fmt"
+
+	"github.com/lib/pq"
+
+	userdomain "github.com/certctl-io/certctl/internal/auth/user/domain"
+	"github.com/certctl-io/certctl/internal/repository"
+)
+
+// UserRepository is the postgres implementation of
+// repository.UserRepository (Auth Bundle 2 Phase 2).
+type UserRepository struct {
+	db *sql.DB
+}
+
+// NewUserRepository constructs a UserRepository.
+func NewUserRepository(db *sql.DB) *UserRepository {
+	return &UserRepository{db: db}
+}
+
+const userColumns = `id, tenant_id, email, display_name, oidc_subject,
+		oidc_provider_id, last_login_at, webauthn_credentials,
+		created_at, updated_at`
+
+func scanUser(row interface{ Scan(...interface{}) error }) (*userdomain.User, error) {
+	var u userdomain.User
+	if err := row.Scan(
+		&u.ID, &u.TenantID, &u.Email, &u.DisplayName, &u.OIDCSubject,
+		&u.OIDCProviderID, &u.LastLoginAt, &u.WebAuthnCredentials,
+		&u.CreatedAt, &u.UpdatedAt,
+	); err != nil {
+		return nil, err
+	}
+	return &u, nil
+}
+
+// Get returns one user by id.
+func (r *UserRepository) Get(ctx context.Context, id string) (*userdomain.User, error) {
+	row := r.db.QueryRowContext(ctx, `SELECT `+userColumns+` FROM users WHERE id = $1`, id)
+	u, err := scanUser(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrUserNotFound
+		}
+		return nil, fmt.Errorf("users get: %w", err)
+	}
+	return u, nil
+}
+
+// GetByOIDCSubject is the Phase 3 hot-path lookup at login time.
+// Returns ErrUserNotFound if no row matches the (provider, subject)
+// tuple — Phase 3's HandleCallback then creates the row via Create.
+func (r *UserRepository) GetByOIDCSubject(ctx context.Context, providerID, subject string) (*userdomain.User, error) {
+	row := r.db.QueryRowContext(ctx, `
+		SELECT `+userColumns+`
+		FROM users
+		WHERE oidc_provider_id = $1 AND oidc_subject = $2`,
+		providerID, subject)
+	u, err := scanUser(row)
+	if err != nil {
+		if errors.Is(err, sql.ErrNoRows) {
+			return nil, repository.ErrUserNotFound
+		}
+		return nil, fmt.Errorf("users get_by_oidc_subject: %w", err)
+	}
+	return u, nil
+}
+
+// Create persists a new user. Translates SQLSTATE 23505 into
+// ErrUserDuplicateOIDCSubject (the unique constraint on
+// (oidc_provider_id, oidc_subject)).
+func (r *UserRepository) Create(ctx context.Context, u *userdomain.User) error {
+	_, err := r.db.ExecContext(ctx, `
+		INSERT INTO users (
+			id, tenant_id, email, display_name, oidc_subject,
+			oidc_provider_id, last_login_at, webauthn_credentials
+		) VALUES ($1, $2, $3, $4, $5, $6, $7, $8)`,
+		u.ID, u.TenantID, u.Email, u.DisplayName, u.OIDCSubject,
+		u.OIDCProviderID, u.LastLoginAt, u.WebAuthnCredentials)
+	if err != nil {
+		var pqErr *pq.Error
+		if errors.As(err, &pqErr) && pqErr.Code == "23505" {
+			return repository.ErrUserDuplicateOIDCSubject
+		}
+		return fmt.Errorf("users create: %w", err)
+	}
+	return nil
+}
+
+// Update writes the mutable fields (email, display_name, last_login_at,
+// webauthn_credentials) back to the row. Immutable: id, tenant_id,
+// oidc_subject, oidc_provider_id, created_at. updated_at = NOW().
+func (r *UserRepository) Update(ctx context.Context, u *userdomain.User) error {
+	res, err := r.db.ExecContext(ctx, `
+		UPDATE users SET
+			email = $2,
+			display_name = $3,
+			last_login_at = $4,
+			webauthn_credentials = $5,
+			updated_at = NOW()
+		WHERE id = $1`,
+		u.ID, u.Email, u.DisplayName, u.LastLoginAt, u.WebAuthnCredentials)
+	if err != nil {
+		return fmt.Errorf("users update: %w", err)
+	}
+	n, _ := res.RowsAffected()
+	if n == 0 {
+		return repository.ErrUserNotFound
+	}
+	return nil
+}
+
+// ListAll returns every user in the tenant, ordered by created_at ASC.
+func (r *UserRepository) ListAll(ctx context.Context, tenantID string) ([]*userdomain.User, error) {
+	rows, err := r.db.QueryContext(ctx,
+		`SELECT `+userColumns+` FROM users WHERE tenant_id = $1 ORDER BY created_at ASC`,
+		tenantID)
+	if err != nil {
+		return nil, fmt.Errorf("users list_all: %w", err)
+	}
+	defer rows.Close()
+
+	var out []*userdomain.User
+	for rows.Next() {
+		u, err := scanUser(rows)
+		if err != nil {
+			return nil, fmt.Errorf("users scan: %w", err)
+		}
+		out = append(out, u)
+	}
+	return out, rows.Err()
+}
diff --git a/internal/repository/postgres/user_test.go b/internal/repository/postgres/user_test.go
new file mode 100644
index 0000000..3c6dcc0
--- /dev/null
+++ b/internal/repository/postgres/user_test.go
@@ -0,0 +1,220 @@
+package postgres_test
+
+import (
+	"context"
+	"errors"
+	"testing"
+
+	userdomain "github.com/certctl-io/certctl/internal/auth/user/domain"
+	"github.com/certctl-io/certctl/internal/repository"
+	"github.com/certctl-io/certctl/internal/repository/postgres"
+)
+
+// newValidUser is shared with oidc_test.go (same _test package).
+func newValidUser(suffix, providerID string) *userdomain.User {
+	return &userdomain.User{
+		ID:                  "u-" + suffix,
+		TenantID:            "t-default",
+		Email:               suffix + "@example.com",
+		DisplayName:         "User " + suffix,
+		OIDCSubject:         "subject-" + suffix,
+		OIDCProviderID:      providerID,
+		WebAuthnCredentials: []byte("[]"),
+	}
+}
+
+func TestUserRepository_CreateAndGet(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("u")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	u := newValidUser("alice", p.ID)
+	if err := userRepo.Create(ctx, u); err != nil {
+		t.Fatalf("Create user: %v", err)
+	}
+
+	got, err := userRepo.Get(ctx, u.ID)
+	if err != nil {
+		t.Fatalf("Get: %v", err)
+	}
+	if got.Email != u.Email {
+		t.Errorf("Email roundtrip: got %q, want %q", got.Email, u.Email)
+	}
+	if string(got.WebAuthnCredentials) != "[]" {
+		t.Errorf("WebAuthnCredentials default = %q; want []", string(got.WebAuthnCredentials))
+	}
+}
+
+func TestUserRepository_GetNotFound(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	repo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	_, err := repo.Get(ctx, "u-nonexistent")
+	if !errors.Is(err, repository.ErrUserNotFound) {
+		t.Errorf("err = %v; want ErrUserNotFound", err)
+	}
+}
+
+func TestUserRepository_GetByOIDCSubject(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("subj")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	u := newValidUser("bob", p.ID)
+	if err := userRepo.Create(ctx, u); err != nil {
+		t.Fatalf("Create user: %v", err)
+	}
+
+	got, err := userRepo.GetByOIDCSubject(ctx, p.ID, u.OIDCSubject)
+	if err != nil {
+		t.Fatalf("GetByOIDCSubject: %v", err)
+	}
+	if got.ID != u.ID {
+		t.Errorf("GetByOIDCSubject returned %q; want %q", got.ID, u.ID)
+	}
+
+	// Wrong subject: not found.
+	_, err = userRepo.GetByOIDCSubject(ctx, p.ID, "wrong-subject")
+	if !errors.Is(err, repository.ErrUserNotFound) {
+		t.Errorf("err = %v; want ErrUserNotFound", err)
+	}
+}
+
+func TestUserRepository_DuplicateOIDCSubjectRejected(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("dupsubj")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	u1 := newValidUser("first", p.ID)
+	if err := userRepo.Create(ctx, u1); err != nil {
+		t.Fatalf("Create u1: %v", err)
+	}
+	u2 := newValidUser("second", p.ID)
+	u2.OIDCSubject = u1.OIDCSubject // collision on (provider, subject) UNIQUE
+	err := userRepo.Create(ctx, u2)
+	if !errors.Is(err, repository.ErrUserDuplicateOIDCSubject) {
+		t.Errorf("Create duplicate (provider, subject) err = %v; want ErrUserDuplicateOIDCSubject", err)
+	}
+}
+
+func TestUserRepository_UpdateMutableFields(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("upd")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	u := newValidUser("carol", p.ID)
+	if err := userRepo.Create(ctx, u); err != nil {
+		t.Fatalf("Create user: %v", err)
+	}
+
+	u.Email = "carol-new@example.com"
+	u.DisplayName = "Carol Renamed"
+	if err := userRepo.Update(ctx, u); err != nil {
+		t.Fatalf("Update: %v", err)
+	}
+	got, err := userRepo.Get(ctx, u.ID)
+	if err != nil {
+		t.Fatalf("Get post-update: %v", err)
+	}
+	if got.Email != "carol-new@example.com" {
+		t.Errorf("Update did not persist Email; got %q", got.Email)
+	}
+	if got.DisplayName != "Carol Renamed" {
+		t.Errorf("Update did not persist DisplayName; got %q", got.DisplayName)
+	}
+	// Immutable: oidc_subject must NOT change.
+	if got.OIDCSubject != u.OIDCSubject {
+		t.Errorf("OIDCSubject mutated: got %q, want %q", got.OIDCSubject, u.OIDCSubject)
+	}
+}
+
+func TestUserRepository_ListAll(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("la")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	for _, suf := range []string{"u1", "u2", "u3"} {
+		u := newValidUser(suf, p.ID)
+		if err := userRepo.Create(ctx, u); err != nil {
+			t.Fatalf("Create %s: %v", suf, err)
+		}
+	}
+
+	out, err := userRepo.ListAll(ctx, "t-default")
+	if err != nil {
+		t.Fatalf("ListAll: %v", err)
+	}
+	if len(out) != 3 {
+		t.Errorf("ListAll count = %d; want 3", len(out))
+	}
+}
+
+// TestUserRepository_DeletingProviderRefusedWhenUsersReference complements
+// the OIDCProviderRepository test of the same shape; pinning both ends
+// of the FK ON DELETE RESTRICT contract.
+func TestUserRepository_FKRestrictsProviderDelete(t *testing.T) {
+	if testing.Short() {
+		t.Skip("integration test in short mode")
+	}
+	db := getTestDB(t).freshSchema(t)
+	providerRepo := postgres.NewOIDCProviderRepository(db)
+	userRepo := postgres.NewUserRepository(db)
+	ctx := context.Background()
+
+	p := newValidProvider("fkrest")
+	if err := providerRepo.Create(ctx, p); err != nil {
+		t.Fatalf("Create provider: %v", err)
+	}
+	u := newValidUser("fkrest-user", p.ID)
+	if err := userRepo.Create(ctx, u); err != nil {
+		t.Fatalf("Create user: %v", err)
+	}
+
+	if err := providerRepo.Delete(ctx, p.ID); !errors.Is(err, repository.ErrOIDCProviderInUse) {
+		t.Errorf("Delete provider (with referencing user) err = %v; want ErrOIDCProviderInUse", err)
+	}
+}
diff --git a/internal/repository/session.go b/internal/repository/session.go
new file mode 100644
index 0000000..c15533c
--- /dev/null
+++ b/internal/repository/session.go
@@ -0,0 +1,124 @@
+package repository
+
+import (
+	"context"
+	"errors"
+
+	sessiondomain "github.com/certctl-io/certctl/internal/auth/session/domain"
+)
+
+// Sentinel errors for the session repositories.
+var (
+	// ErrSessionNotFound: Get returned no row. Phase 4 maps to 401
+	// (the cookie either expired or was forged with a known-good key
+	// id but stale session id).
+	ErrSessionNotFound = errors.New("session: not found")
+
+	// ErrSessionRevoked: Get found a row but RevokedAt is set. Phase 4
+	// maps to 401.
+	ErrSessionRevoked = errors.New("session: revoked")
+
+	// ErrSessionExpired: Get found a row but the absolute expiry has
+	// passed (Phase 4 also enforces idle expiry but that's a service-
+	// level check against last_seen_at, not a repository sentinel).
+	ErrSessionExpired = errors.New("session: expired")
+
+	// ErrSessionSigningKeyNotFound: GetActive returned no row. Phase 4
+	// EnsureInitialSigningKey treats this as "boot-time provisioning
+	// needed" and mints the first key.
+	ErrSessionSigningKeyNotFound = errors.New("session: signing key not found")
+
+	// ErrSessionSigningKeyInUse: Delete (full purge, not Retire) failed
+	// because at least one sessions row still references the key. Phase
+	// 4's GarbageCollect waits for sessions to expire before purging.
+	ErrSessionSigningKeyInUse = errors.New("session: signing key still referenced by active sessions")
+)
+
+// SessionRepository wraps the sessions table. Two cookie shapes share
+// the rows: post-login sessions (1h-idle/8h-absolute) and pre-login
+// sessions (10-minute TTL, IsPreLogin=true; carry OIDC state + nonce
+// + PKCE verifier across the IdP redirect).
+type SessionRepository interface {
+	// Create persists a session row. Caller MUST have called
+	// s.Validate(). Returns ErrAuthDuplicateName-shape on the
+	// extremely-unlikely id collision (the id is a 32-byte random;
+	// callers SHOULD generate fresh ids on the second attempt).
+	Create(ctx context.Context, s *sessiondomain.Session) error
+
+	// Get returns a session by id. ErrSessionNotFound on miss.
+	// Returns the row even if revoked / expired so the service layer
+	// can produce the right 401 reason code (revoked vs expired vs
+	// not-found are all 401 to the wire but distinguishable in audit).
+	Get(ctx context.Context, id string) (*sessiondomain.Session, error)
+
+	// ListByActor returns every active (non-revoked, non-expired,
+	// non-pre-login) session for an actor. Used by the GUI's
+	// /v1/auth/sessions surface so users can revoke their old laptops.
+	ListByActor(ctx context.Context, actorID, actorType, tenantID string) ([]*sessiondomain.Session, error)
+
+	// UpdateLastSeen sets last_seen_at = NOW() for the named session.
+	// Phase 4's middleware calls this on every request to keep the
+	// idle-expiry sliding window fresh.
+	UpdateLastSeen(ctx context.Context, id string) error
+
+	// Revoke sets revoked_at = NOW() for the named session. Subsequent
+	// Get returns the row with RevokedAt set; Phase 4's Validate maps
+	// to 401.
+	Revoke(ctx context.Context, id string) error
+
+	// RevokeAllForActor sets revoked_at = NOW() on every active session
+	// for an actor. Used on role change, fired-employee scenarios, and
+	// the back-channel logout endpoint (Phase 5).
+	RevokeAllForActor(ctx context.Context, actorID, actorType, tenantID string) error
+
+	// GarbageCollectExpired deletes sessions whose absolute expiry
+	// has passed AND whose revoked_at is older than the configurable
+	// retention window (default 24h). Pre-login rows older than the
+	// 10-minute TTL are also deleted. Returns the number of rows
+	// deleted.
+	GarbageCollectExpired(ctx context.Context) (int, error)
+
+	// Delete unconditionally removes a session row. Used for the
+	// admin-only "purge a specific session" surface (rarely needed;
+	// Revoke is the normal path).
+	Delete(ctx context.Context, id string) error
+}
+
+// SessionSigningKeyRepository wraps the session_signing_keys table.
+// Phase 4's Service.RotateSigningKey + EnsureInitialSigningKey + the
+// scheduler-driven retention sweep consume this.
+type SessionSigningKeyRepository interface {
+	// List returns every signing key in the tenant (including
+	// retired). Order: created_at DESC.
+	List(ctx context.Context, tenantID string) ([]*sessiondomain.SessionSigningKey, error)
+
+	// GetActive returns the most-recently-created non-retired key.
+	// ErrSessionSigningKeyNotFound when no non-retired key exists
+	// (Phase 4's EnsureInitialSigningKey treats this as "mint first
+	// key").
+	GetActive(ctx context.Context, tenantID string) (*sessiondomain.SessionSigningKey, error)
+
+	// Get returns one key by id (including retired keys; Phase 4's
+	// Validate consults this for cookies signed under retired-but-
+	// in-retention keys).
+	Get(ctx context.Context, id string) (*sessiondomain.SessionSigningKey, error)
+
+	// Add persists a new signing key. Caller MUST have called
+	// k.Validate() and encrypted the key_material via
+	// internal/crypto/encryption.go. CreatedAt defaults to NOW() if
+	// zero.
+	Add(ctx context.Context, k *sessiondomain.SessionSigningKey) error
+
+	// Retire marks an active key as retired (sets retired_at = NOW()).
+	// The key stays in the table for verification of cookies signed
+	// under it; the scheduler's retention sweep purges it after the
+	// configurable retention window (default 24h beyond retired_at).
+	Retire(ctx context.Context, id string) error
+
+	// Delete unconditionally removes a signing key row. Returns
+	// ErrSessionSigningKeyInUse if any sessions row still references
+	// the key (FK ON DELETE RESTRICT). Phase 4's GarbageCollect calls
+	// this only after RetentionWindow has passed AND no sessions
+	// reference the key.
+	Delete(ctx context.Context, id string) error
+}
diff --git a/internal/repository/user.go b/internal/repository/user.go
new file mode 100644
index 0000000..f40b923
--- /dev/null
+++ b/internal/repository/user.go
@@ -0,0 +1,46 @@
+package repository
+
+import (
+	"context"
+	"errors"
+
+	userdomain "github.com/certctl-io/certctl/internal/auth/user/domain"
+)
+
+// Sentinel errors for the user repository.
+var (
+	// ErrUserNotFound: Get / GetByOIDCSubject returned no row. Phase
+	// 3's HandleCallback treats this as "first login for this person;
+	// create the row".
+	ErrUserNotFound = errors.New("user: not found")
+
+	// ErrUserDuplicateOIDCSubject: Create tripped the
+	// (oidc_provider_id, oidc_subject) UNIQUE constraint. HTTP 409.
+	ErrUserDuplicateOIDCSubject = errors.New("user: a user with this provider+subject already exists")
+)
+
+// UserRepository wraps the users table. Phase 3's HandleCallback
+// uses GetByOIDCSubject + Create + Update on every login; the GUI's
+// admin user-list surface uses ListAll + Get.
+type UserRepository interface {
+	// Get returns one user by id. ErrUserNotFound on miss.
+	Get(ctx context.Context, id string) (*userdomain.User, error)
+
+	// GetByOIDCSubject is the Phase 3 hot-path lookup at login time.
+	// Returns the existing row if present, ErrUserNotFound otherwise.
+	GetByOIDCSubject(ctx context.Context, providerID, subject string) (*userdomain.User, error)
+
+	// Create persists a new user. Caller MUST have called u.Validate().
+	// Returns ErrUserDuplicateOIDCSubject on UNIQUE constraint trip.
+	Create(ctx context.Context, u *userdomain.User) error
+
+	// Update writes the mutable field set back to the row. Immutable
+	// fields (id, tenant_id, oidc_subject, oidc_provider_id,
+	// created_at) are preserved. updated_at is set to NOW() by the
+	// implementation.
+	Update(ctx context.Context, u *userdomain.User) error
+
+	// ListAll returns every user in the tenant. Order:
+	// created_at ASC. Used by the GUI's admin surface.
+	ListAll(ctx context.Context, tenantID string) ([]*userdomain.User, error)
+}