feat(contacts): apply duplicate merge plans

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## 0.27.2 - Unreleased
 
+### Added
+
+- Contacts: add guarded `contacts dedupe --apply` merging with exact dry-run plans, repeatable `--resource` scoping, confirmation, full updatable-field preservation, etag checks before deletion, and refusal of ambiguous or unmergeable groups. (#815) — thanks @privatenumber.
+
 ### Changed
 
 - Gmail: show ordinary message bodies in full by default in text output, retain a generous cap for unusually large messages, and point truncated output to `--full` or `--json`. (#807) — thanks @privatenumber.

README.md

@@ -316,9 +316,16 @@ Docs: [contacts dedupe](docs/contacts-dedupe.md),
 gog contacts search alice --json
 gog contacts export --all --out contacts.vcf
 
-# Preview only: no merge/delete/update call is made.
+# Preview by default.
 gog contacts dedupe --json
-gog contacts dedupe --match email,phone,name --dry-run
+gog contacts dedupe --match email,phone,name
+
+# Inspect the mutation plan, then apply with confirmation.
+gog contacts dedupe --apply --dry-run --json
+gog contacts dedupe --apply
+
+# Scope automation to exact reviewed contact resources.
+gog contacts dedupe --resource people/123 --resource people/456 --apply --force --json
 ```
 
 ### Docs

docs/commands.generated.md

@@ -208,7 +208,7 @@ Generated from `gog schema --json`.
     - [`gog config unset (rm,del,remove) <key>`](commands/gog-config-unset.md) - Unset a config value
   - [`gog contacts (contact) <command> [flags]`](commands/gog-contacts.md) - Google Contacts
     - [`gog contacts (contact) create (add,new) [flags]`](commands/gog-contacts-create.md) - Create a contact
-    - [`gog contacts (contact) dedupe [flags]`](commands/gog-contacts-dedupe.md) - Find likely duplicate contacts (preview only)
+    - [`gog contacts (contact) dedupe [flags]`](commands/gog-contacts-dedupe.md) - Find likely duplicate contacts and optionally merge them
     - [`gog contacts (contact) delete (rm,del,remove) <resourceName>`](commands/gog-contacts-delete.md) - Delete a contact
     - [`gog contacts (contact) directory <command>`](commands/gog-contacts-directory.md) - Directory contacts
       - [`gog contacts (contact) directory list [flags]`](commands/gog-contacts-directory-list.md) - List people from the Workspace directory

docs/commands/README.md

@@ -259,7 +259,7 @@ Generated pages: 646.
     - [gog config unset](gog-config-unset.md) - Unset a config value
   - [gog contacts](gog-contacts.md) - Google Contacts
     - [gog contacts create](gog-contacts-create.md) - Create a contact
-    - [gog contacts dedupe](gog-contacts-dedupe.md) - Find likely duplicate contacts (preview only)
+    - [gog contacts dedupe](gog-contacts-dedupe.md) - Find likely duplicate contacts and optionally merge them
     - [gog contacts delete](gog-contacts-delete.md) - Delete a contact
     - [gog contacts directory](gog-contacts-directory.md) - Directory contacts
       - [gog contacts directory list](gog-contacts-directory-list.md) - List people from the Workspace directory

docs/commands/gog-contacts-dedupe.md

@@ -2,7 +2,7 @@
 
 > Generated from `gog schema --json`. Do not edit this page by hand; run `make docs-commands`.
 
-Find likely duplicate contacts (preview only)
+Find likely duplicate contacts and optionally merge them
 
 ## Usage
 
@@ -20,6 +20,7 @@ gog contacts (contact) dedupe [flags]
 | --- | --- | --- | --- |
 | `--access-token` | `string` |  | Use provided access token directly (bypasses stored refresh tokens; token expires in ~1h) |
 | `-a`<br>`--account`<br>`--acct` | `string` |  | Account email, alias, or auto for authenticated Google API commands |
+| `--apply`<br>`--merge` | `bool` |  | Merge duplicate groups and delete redundant contacts (requires confirmation) |
 | `--client` | `string` |  | OAuth client name (selects stored credentials + token bucket) |
 | `--color` | `string` | auto | Color output: auto\|always\|never |
 | `--disable-commands` | `string` |  | Comma-separated list of disabled commands; dot paths allowed |
@@ -36,6 +37,7 @@ gog contacts (contact) dedupe [flags]
 | `--max`<br>`--limit` | `int64` | 0 | Max contacts to scan (0 = all) |
 | `--no-input`<br>`--non-interactive`<br>`--noninteractive` | `bool` |  | Never prompt; fail instead (useful for CI) |
 | `-p`<br>`--plain`<br>`--tsv` | `bool` | false | Output stable, parseable text to stdout (TSV; no colors) |
+| `--resource` | `[]string` |  | Limit dedupe to exact contact resource names (people/...); repeatable |
 | `--results-only` | `bool` |  | In JSON mode, emit only the primary result (drops envelope fields like nextPageToken) |
 | `--select`<br>`--pick`<br>`--project` | `string` |  | In JSON mode, select comma-separated fields (best-effort; supports dot paths). Desire path: use --fields for most commands. |
 | `-v`<br>`--verbose` | `bool` |  | Enable verbose logging |

docs/commands/gog-contacts.md

@@ -17,7 +17,7 @@ gog contacts (contact) <command> [flags]
 ## Subcommands
 
 - [gog contacts create](gog-contacts-create.md) - Create a contact
-- [gog contacts dedupe](gog-contacts-dedupe.md) - Find likely duplicate contacts (preview only)
+- [gog contacts dedupe](gog-contacts-dedupe.md) - Find likely duplicate contacts and optionally merge them
 - [gog contacts delete](gog-contacts-delete.md) - Delete a contact
 - [gog contacts directory](gog-contacts-directory.md) - Directory contacts
 - [gog contacts export](gog-contacts-export.md) - Export contacts as vCard (.vcf)

docs/contacts-dedupe.md

@@ -1,11 +1,11 @@
-# Contacts Dedupe Preview
+# Contacts Dedupe
 
 read_when:
 - Finding duplicate Google Contacts.
 - Reviewing or changing `gog contacts dedupe`.
 
 `gog contacts dedupe` finds likely duplicate personal contacts and prints a
-merge plan. It is preview-only: it does not merge, update, or delete contacts.
+merge plan. Preview is the default; `--apply` performs the reviewed plan.
 
 ## Command Page
 
@@ -31,6 +31,49 @@ Name matching is opt-in because it can produce false positives:
 gog contacts dedupe --match email,phone,name
 ```
 
+## Apply A Merge
+
+Review the plan first:
+
+```bash
+gog contacts dedupe --json
+```
+
+Then inspect the exact mutation plan without changing contacts:
+
+```bash
+gog contacts dedupe --apply --dry-run --json
+```
+
+For automation, copy the contact resource names from the reviewed preview and
+scope both dry-run and apply to that exact set:
+
+```bash
+gog contacts dedupe \
+  --resource people/123 \
+  --resource people/456 \
+  --apply \
+  --dry-run \
+  --json
+```
+
+Apply interactively:
+
+```bash
+gog contacts dedupe --apply
+```
+
+Non-interactive automation must explicitly skip confirmation:
+
+```bash
+gog contacts dedupe \
+  --resource people/123 \
+  --resource people/456 \
+  --apply \
+  --force \
+  --json
+```
+
 ## Output
 
 The command groups contacts that share a matching key. JSON output includes:
@@ -42,16 +85,36 @@ The command groups contacts that share a matching key. JSON output includes:
 - `matched_on`: duplicate email/phone/name keys that caused the group
 - `members`: all contacts in the group
 
-## Safety
+Applied output also includes:
 
-`contacts dedupe` is read-only. There is no apply flag.
+- `applied`: whether mutations ran
+- `groups_merged`: groups completed
+- `contacts_deleted`: redundant contacts deleted
+- `update_fields`: People API fields unioned into the primary contact
+- `delete`: redundant contacts removed after their data was copied
 
-Use `--dry-run` in automation anyway when you want a uniform safety habit across
-commands:
+## Safety
 
-```bash
-gog contacts dedupe --dry-run --json
-```
+`contacts dedupe` remains read-only unless `--apply` is present. Apply mode:
+
+- requires confirmation unless `--force` is present
+- honors `--dry-run`
+- supports repeatable `--resource` scoping so automation can apply an exact
+  reviewed contact set
+- reads contact-source data only
+- refreshes each contact before planning
+- updates the selected primary before deleting anything
+- rechecks each redundant contact's etag immediately before deletion
+- refuses groups with conflicting singleton fields (`names`, `birthdays`,
+  `biographies`, or `genders`)
+- refuses secondary contacts with photos or other fields the People API cannot
+  preserve through `updateContact`
+
+The People API does not expose Google Contacts' native merge operation. gog
+therefore unions all API-updatable fields into the selected primary, then
+deletes redundant contacts sequentially. If a request fails, the command stops
+and reports completed groups/deletions; copied data remains on the primary and
+undeleted contacts remain intact.
 
 Use `--fail-empty` in scheduled checks when "no duplicates" should be reported
 as a distinct exit code:

docs/index.md

@@ -40,7 +40,7 @@ gog slides create-from-markdown "Weekly update" --content-file slides.md
 - **Runtime discovery.** `gog schema --json` exposes command shape, stable exit codes, output modes, and effective safety state.
 - **Multi-account, multi-client.** Many Google accounts and OAuth client projects in one config; OAuth, direct access tokens, ADC, and Workspace service accounts all supported.
 - **One automation contract.** Humans, scripts, CI, and agents use the same commands, with JSON/TSV output, non-interactive operation, stable exit codes, untrusted-content wrapping, runtime command guards, and baked safety profiles.
-- **Read-only audits.** Drive `tree`, `du`, `inventory`; Contacts `dedupe` preview; raw API JSON dumps without ever mutating remote state.
+- **Preview-first audits.** Drive `tree`, `du`, `inventory`; Contacts `dedupe` previews by default and requires explicit `--apply` for guarded merges; raw API JSON dumps never mutate remote state.
 - **Generated reference.** Every command has a docs page produced from `gog schema --json`.
 
 ## Pick your path

docs/live-testing.md

@@ -34,6 +34,7 @@ available services. Recent-feature coverage includes:
 - Drive shortcuts, revisions, and persisted changes polling.
 - Gmail thread-aware drafts, attachment metadata preservation/clearing, and
   explicit thread archive semantics.
+- Contacts duplicate merge dry-run, apply, merged-field readback, and cleanup.
 - CLI schema exit codes, Git-style help, output-mode precedence, and early
   validation errors.
 

docs/spec.md

@@ -370,7 +370,7 @@ after the bounded retry window, the command exits with retryable code `8`.
 - `gog classroom guardian-invitations get <studentId> <invitationId>`
 - `gog classroom guardian-invitations create <studentId> --email EMAIL`
 - `gog classroom profile [userId]`
-- `gog contacts dedupe [--match email,phone,name] [--max N]`
+- `gog contacts dedupe [--match email,phone,name] [--max N] [--resource people/...] [--apply]`
 - `gog gmail search <query> [--max N] [--page TOKEN]`
 - `gog gmail messages search <query> [--max N] [--page TOKEN] [--include-body] [--body-format text|html] [--full]`
 - `gog gmail autoreply <query> [--max N] [--subject S] [--body B|--body-file PATH|--body-html HTML] [--from addr] [--reply-to addr] [--label L] [--archive] [--mark-read] [--skip-bulk] [--allow-self]`

internal/cmd/contacts.go

@@ -16,7 +16,7 @@ type ContactsCmd struct {
 	List      ContactsListCmd      `cmd:"" name:"list" aliases:"ls" help:"List contacts"`
 	Get       ContactsGetCmd       `cmd:"" name:"get" aliases:"info,show" help:"Get a contact"`
 	Export    ContactsExportCmd    `cmd:"" name:"export" help:"Export contacts as vCard (.vcf)"`
-	Dedupe    ContactsDedupeCmd    `cmd:"" name:"dedupe" help:"Find likely duplicate contacts (preview only)"`
+	Dedupe    ContactsDedupeCmd    `cmd:"" name:"dedupe" help:"Find likely duplicate contacts and optionally merge them"`
 	Create    ContactsCreateCmd    `cmd:"" name:"create" aliases:"add,new" help:"Create a contact"`
 	Update    ContactsUpdateCmd    `cmd:"" name:"update" aliases:"edit,set" help:"Update a contact"`
 	Delete    ContactsDeleteCmd    `cmd:"" name:"delete" aliases:"rm,del,remove" help:"Delete a contact"`

internal/cmd/contacts_dedupe.go

@@ -12,9 +12,11 @@ import (
 )
 
 type ContactsDedupeCmd struct {
-	Match     string `name:"match" help:"Match fields: email,phone,name" default:"email,phone"`
-	Max       int64  `name:"max" aliases:"limit" help:"Max contacts to scan (0 = all)" default:"0"`
-	FailEmpty bool   `name:"fail-empty" aliases:"non-empty,require-results" help:"Exit with code 3 if no duplicates"`
+	Match     string   `name:"match" help:"Match fields: email,phone,name" default:"email,phone"`
+	Max       int64    `name:"max" aliases:"limit" help:"Max contacts to scan (0 = all)" default:"0"`
+	Resources []string `name:"resource" help:"Limit dedupe to exact contact resource names (people/...); repeatable"`
+	Apply     bool     `name:"apply" aliases:"merge" help:"Merge duplicate groups and delete redundant contacts (requires confirmation)"`
+	FailEmpty bool     `name:"fail-empty" aliases:"non-empty,require-results" help:"Exit with code 3 if no duplicates"`
 }
 
 func (c *ContactsDedupeCmd) Run(ctx context.Context, flags *RootFlags) error {
@@ -31,24 +33,57 @@ func (c *ContactsDedupeCmd) Run(ctx context.Context, flags *RootFlags) error {
 	if c.Max < 0 {
 		return usage("--max must be >= 0")
 	}
+	resources, err := normalizeContactsDedupeResources(c.Resources)
+	if err != nil {
+		return err
+	}
+	if len(resources) > 0 && c.Max != 0 {
+		return usage("--max cannot be combined with --resource")
+	}
 
 	svc, err := peopleContactsService(ctx, account)
 	if err != nil {
 		return err
 	}
-	contacts, err := contactsDedupeList(ctx, svc, c.Max)
+	var contacts []*people.Person
+	if len(resources) > 0 {
+		contacts, err = contactsDedupeGetResources(ctx, svc, resources)
+	} else {
+		contacts, err = contactsDedupeList(ctx, svc, c.Max)
+	}
 	if err != nil {
 		return wrapPeopleAPIError(err)
 	}
 
 	groups := buildContactsDedupeGroups(contacts, match)
-	if err := writeContactsDedupe(ctx, u, groups, len(contacts)); err != nil {
-		return err
-	}
 	if len(groups) == 0 {
+		if writeErr := writeContactsDedupe(ctx, u, groups, len(contacts)); writeErr != nil {
+			return writeErr
+		}
 		return failEmptyExit(c.FailEmpty)
 	}
-	return nil
+	if !c.Apply {
+		return writeContactsDedupe(ctx, u, groups, len(contacts))
+	}
+
+	plans, err := prepareContactsDedupeApply(ctx, svc, groups, match)
+	if err != nil {
+		return err
+	}
+	deleteCount := contactsDedupeDeleteCount(plans)
+	if u != nil {
+		u.Err().Linef("Prepared %d duplicate group(s); %d redundant contact(s) will be deleted", len(plans), deleteCount)
+	}
+	if confirmErr := dryRunAndConfirmDestructive(ctx, flags, "contacts.dedupe.apply", contactsDedupeApplyPayload(len(contacts), plans),
+		contactsDedupeApplyAction(len(plans), deleteCount)); confirmErr != nil {
+		return confirmErr
+	}
+
+	result, err := applyContactsDedupePlans(ctx, svc, len(contacts), plans)
+	if err != nil {
+		return err
+	}
+	return writeContactsDedupeApplyResult(ctx, u, result)
 }
 
 type contactsDedupeMatch struct {
@@ -79,6 +114,39 @@ func parseContactsDedupeMatch(value string) (contactsDedupeMatch, error) {
 	return out, nil
 }
 
+func normalizeContactsDedupeResources(values []string) ([]string, error) {
+	seen := map[string]bool{}
+	out := make([]string, 0, len(values))
+	for _, value := range values {
+		resource := strings.TrimSpace(value)
+		if !strings.HasPrefix(resource, "people/") || len(resource) == len("people/") {
+			return nil, usagef("invalid --resource %q (expected people/...)", value)
+		}
+		if seen[resource] {
+			continue
+		}
+		seen[resource] = true
+		out = append(out, resource)
+	}
+	return out, nil
+}
+
+func contactsDedupeGetResources(ctx context.Context, svc *people.Service, resources []string) ([]*people.Person, error) {
+	contacts := make([]*people.Person, 0, len(resources))
+	for _, resource := range resources {
+		person, err := svc.People.Get(resource).
+			PersonFields(contactsReadMask).
+			Sources(contactsDedupeContactSource).
+			Context(ctx).
+			Do()
+		if err != nil {
+			return nil, err
+		}
+		contacts = append(contacts, person)
+	}
+	return contacts, nil
+}
+
 func contactsDedupeList(ctx context.Context, svc *people.Service, maxResults int64) ([]*people.Person, error) {
 	var out []*people.Person
 	pageToken := ""
@@ -92,6 +160,7 @@ func contactsDedupeList(ctx context.Context, svc *people.Service, maxResults int
 			PageSize(pageSize).
 			PageToken(pageToken).
 			RequestSyncToken(false).
+			Sources("READ_SOURCE_TYPE_CONTACT").
 			Context(ctx).
 			Do()
 		if err != nil {