POST/v1/contacts/tagstable

Add tags to contacts

Needs: Create and edit contacts, tags, contact groups and custom fields (crm:write)
Plan: Any plan with API access
Limits: 60 a minute per key
Dry run: Yes — every check runs with ?dry_run=true, nothing changes
Undo: Remove the tags again with Remove tags from contacts.

Adds tags to up to 500 contacts at once. Tag names that do not exist yet are created. Contacts keep their other tags; tagging twice is harmless.

Try it

Edit as JSON

contact_idsrequiredlist

Contact ids.

tagsrequiredlist

Tag names or ids. Names that do not exist yet are created.

Idempotency-Keyoptional — made for you if empty

Protects against doing it twice if you retry: a retry with the same key gets the first answer back instead of running again.

Test mode (dry run): nothing will change

Run liveTurns test mode off for this page only. It switches back when you leave the page.

curl -X POST 'https://mcp.wa-api.cloud/v1/contacts/tag?dry_run=true' \
  -H "Authorization: Bearer $API_KEY" \
  -H 'Content-Type: application/json' \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{
  "contact_ids": [
    "48213"
  ],
  "tags": [
    "opted-out"
  ]
}'

The code reads your key from $API_KEY.

Body

Body fields
Field	Type	What it is
contact_idsrequired	array of string \| integer	Contact ids.1–500 itemsSigned in? Pick one from your data with “My data”.
tagsrequired	array of string \| integer	Tag names or ids. Names that do not exist yet are created.1–20 itemsSigned in? Pick one from your data with “My data”.

Headers

Headers
Field	Type	What it is
Authorizationrequired	header	`Bearer $API_KEY` — your API key.
Api-Version	header	The API version to use, e.g. `2026-10-01`. Default: the version your key is pinned to.one of: `2026-10-01` · pattern `^\d{4}-\d{2}-\d{2}$`
Idempotency-Key	header	Any unique string (8–128 characters). A retry with the same key returns the first answer instead of running twice. Kept 24 hours.pattern `^[A-Za-z0-9._:-]+$` · 8–128 characters

Response `200`

Counts and per-contact failures.

Response fields
Field	Type	What it is
requestedrequired	integer	-9007199254740991–9007199254740991
succeededrequired	integer	-9007199254740991–9007199254740991
failedrequired	integer	-9007199254740991–9007199254740991
failuresrequired	array of object	Per-contact failures (first 50).
idrequired	string
coderequired	string
messagerequired	string
stopped_earlyrequired	boolean	true when a fatal error (permission, rate limit) stopped the remaining batches; retry those ids.
matched	integer or null	By filter: the contacts that matched when the change started (the ones changed).-9007199254740991–9007199254740991
dry_run	boolean	`true` when this was a dry run: every check ran and nothing changed.

Errors

Errors are application/problem+json. Branch on code.

Status	Code	When
400	invalid_input	A field is missing or has the wrong format. `errors[]` points at each field.
401	unauthenticated	The Authorization header is missing, the key is unknown, expired or revoked.
403	entitlement_required	The workspace's plan does not include API access (`api_access`).
403	insufficient_scope	The key does not have the permission this operation needs.
409	conflict	Also returned while a request with the same Idempotency-Key is still running.
429	rate_limited	The key or workspace went over its rate limit. Wait for `Retry-After` seconds.
503	upstream_unavailable	A service behind the API is briefly unavailable. Safe to retry with backoff.
504	timeout	The change did not finish in time. Retry with the same Idempotency-Key: it never runs twice.

Examples

Mark a contact as opted out

Request body

{
  "contact_ids": [
    "48213"
  ],
  "tags": [
    "opted-out"
  ]
}

Response 200

{
  "requested": 1,
  "succeeded": 1,
  "failed": 0,
  "failures": [],
  "stopped_early": false
}

Webhook events

These events can fire after this call. Subscribe an endpoint to hear about them.

tag.created/1

Operation path

The same operation is also at POST /v1/ops/crm_tag_contacts, with every field in the JSON body.