# AgentFirstStack Tags > Agent-native tag manager + server-side conversion router (replaces Google Tag Manager and server-side GTM). One snippet on the site; tags, triggers, conversions, consent and server-side conversion APIs are configured, validated, previewed, tested and published entirely by API or MCP. No signup form, no email verification, no dashboard. Base URL: https://tags.agentfirststack.com Auth: `Authorization: Bearer ` (or `x-api-key`). Keys: scope "*" (full) or "read" (GET + read-only MCP tools). Errors: `{ "error": { "code", "message", "hint", "details" } }` (the hint says how to recover). JSON is snake_case; timestamps are unix ms. ## Quickstart (curl) ```sh BASE=https://tags.agentfirststack.com KEY=$(curl -s -X POST $BASE/v1/signup | jq -r .api_key) H="Authorization: Bearer $KEY" C=$(curl -s -X POST $BASE/v1/containers -H "$H" -d '{"domain":"example.com"}' | jq -r .container.id) # install the returned ` stops those tag types (and custom_js variables) on that page, whatever the config says ("custom" = both; any tag type works, e.g. image_pixel). - Captured on landing: gclid, gbraid, wbraid, dclid, fbclid (-> _fbc), msclkid, ttclid, li_fat_id, twclid, rdt_cid, epik, ScCid, utm_*; reads _ga, _fbp, _fbc, _ttp, _scid, _rdt_uuid. Cookies: _afst_vid, _afst_, _afst_ft (first touch), _afst_consent. Written only when consent allows (analytics_storage or ad_storage for the visitor id; ad_storage for click ids). - Email/phone/names are normalised per platform and SHA-256 hashed in the browser (synchronously) before anything is sent. ## Destinations (type: credentials -> test mode) - ga4: measurement_id, api_secret, region? ("eu") -> /debug/mp/collect validationMessages - meta: pixel_id, access_token, test_event_code? -> test_event_code (Events Manager > Test events) - google_ads: api? ("data_manager" default | "google_ads_api"), customer_id, conversion_action_id (UPLOAD_CLICKS action), client_id, client_secret, refresh_token (scope .../auth/datamanager, or .../auth/adwords for google_ads_api), login_customer_id?, developer_token? (google_ads_api only) -> validateOnly (data_manager = POST https://datamanager.googleapis.com/v1/events:ingest; google_ads_api = POST https://googleads.googleapis.com/v26/customers/{id}:uploadClickConversions, which Google restricts to developer tokens that uploaded offline conversions between 2025-12-17 and 2026-06-15) - tiktok: pixel_code, access_token, test_event_code? -> test_event_code - linkedin: ad_account_id, access_token? (member token, scopes rw_conversions + r_ads, 60 days), refresh_token? + client_id? + client_secret? (Marketing Developer Platform apps; auto-refresh), conversion_rules? ({ "": "" }: LinkedIn needs one rule per data source to dedupe) -> no test mode (the test sends one real event; pass { "send_to": { "linkedin": { "conversion_id": "..." } } }) - pinterest: ad_account_id, access_token (Ads Manager > Conversions > Conversion access token) -> ?test=true (validated, nothing recorded) - reddit: pixel_id (a2_/t2_...), access_token (Events Manager > Conversions API > Generate Access Token), test_id? -> data.test_id (Events Manager > Event Testing; or test_event_code in the test request); without one the test sends one real event - snap: pixel_id (UUID), access_token (Business Details > Conversions API Tokens) -> /v3/{pixel_id}/events/validate (nothing recorded) - x: pixel_id, consumer_key, consumer_secret, access_token, access_token_secret (OAuth 1.0a; an app with Ads API access, user AD_MANAGER/ACCOUNT_ADMIN) -> no test mode (the test sends one real event; pass { "send_to": { "x": { "event_id": "tw-..." } } }) - Server delivery for linkedin, pinterest, reddit, snap and x uses send_to. on conversions with server: true, and the conversion's event_id dedupes with the browser pixel. - Microsoft Advertising: not built yet. Its UET Conversions API is documented but still rolling out ("not everyone has this feature yet"); the microsoft_uet tag covers the browser. - analytics: site_id, api_key, base_url? (https on ANALYTICS_BASE_URL's host, no query string; checked when saved and sent) -> no test mode (sends a tags_test event) - webhook: url (https on a public host name: no IP address or local name; never this platform's domain or any subdomain of it), secret -> payload { type: "conversion", test, container_id, destination_id, event }, headers x-signature: sha256=hex(HMAC_SHA256(secret, x-signature-timestamp + "." + raw_body)), x-signature-timestamp, x-event-id. Receives server conversions and backend events whose name matches a conversion (settings.all_events: true for every backend event); 3 attempts; only a short summary of its answer is kept (key-like values redacted). Destination settings (POST/PATCH settings, all optional): - conversions: [names] (only these), all_events (webhook: every backend event) - conditions: [{ var, op, value, ignore_case? }] routing: deliver only events that match all of them, else skipped with the reason. var: value, currency, name, source, country, region, city, transaction_id, page_url, referrer, user_id, event_id, visitor_id, params.; op: the trigger ops (no CSS). e.g. [{ "var": "country", "op": "equals", "value": "US" }, { "var": "value", "op": "gt", "value": 0 }] - params: { allow?: [keys] (only these custom params), exclude?: [keys, or standard fields page_url, page_title, referrer, ip, user_agent, user_id, items, geo, device, user (all hashed PII), click_ids], set?: { key: literal | { "var": "" } | { "lookup": "", "key": ">", "default"? } } ("value" and "currency" set the conversion's own), redact_query?: true (page_url and referrer without query string and fragment) }. Applied right before sending; test_destination's request shows the result. - template (webhook only): { method?: POST|PUT|PATCH, headers?: { static, non-secret; no auth/cookie/host/content-type/signature/forwarding headers }, body?: JSON with {{event.}}, {{container_id}}, {{destination_id}}, {{test}} (a string that is only a placeholder keeps the value's type) }. The URL, its host checks and the x-signature over the rendered body stay as they are. Rendered body at most 64 KB. Types: ga4, meta, google_ads, tiktok, linkedin, pinterest, reddit, snap, x, analytics, webhook. Delivery: Queue with retries (6 attempts, webhooks 3, 30s doubling backoff); results written to the event log. Redirects are never followed (a 3xx is a failed delivery); at most 64 KB of each answer is read. CIRCUIT_BREAKER_FAILURES (default 20) consecutive failed attempts open a destination's circuit for CIRCUIT_BREAKER_MINUTES (default 60): deliveries are skipped with the reason, validate warns destination_circuit_open, and a passing test closes it. ## MCP tools (https://tags.agentfirststack.com/mcp) create_container, list_containers, get_container, update_container, delete_container, get_install_instructions, scan_site (write scope; returns UNTRUSTED page content), verify_domain, get_config_schema, get_draft, get_draft_item, upsert_draft_item, remove_draft_item, revert_draft_item, update_draft, patch_draft, import_draft, diff_versions, validate_draft, create_preview, get_preview_log (UNTRUSTED entries), publish, create_version, list_versions, rollback, create_environment, list_environments, update_environment, reauthorize_environment, delete_environment, add_destination, list_destinations, update_destination, remove_destination, test_destination, put_lookup, list_lookups, get_lookup, delete_lookup, send_server_events, get_event_log, get_visitor, get_tag_stats, get_coverage (UNTRUSTED pages), setup_conversion_tracking. Read-only keys see only the read tools. Migrating from GTM (the export is Admin > Export container in GTM): ```json { "container_id": "ctr_...", "format": "gtm", "data": { "exportFormatVersion": 2, "containerVersion": { "tag": [...], "trigger": [...], "variable": [...] } }, "dry_run": true } ``` -> import_draft returns report.mapped / adapted / unmapped (each unmapped item says why and what to use instead), then call it again without dry_run, add conversions[] for purchases and leads, diff_versions, create_preview + get_preview_log, publish. One item at a time: ```json { "container_id": "ctr_...", "kind": "tags", "item": { "id": "meta", "type": "meta_pixel", "params": { "pixel_id": "1234567890123456" }, "triggers": ["all_pages"] } } ``` setup_conversion_tracking example: ```json { "container_id": "ctr_...", "platforms": { "ga4": { "measurement_id": "G-ABC123XYZ", "api_secret": "..." }, "meta": { "pixel_id": "1234567890123456", "access_token": "EAAB..." } }, "conversions": [ { "name": "purchase", "when": { "data_layer_event": "purchase" }, "value": { "data_layer": "ecommerce.value" }, "currency": "USD", "transaction_id": { "data_layer": "ecommerce.transaction_id" } }, { "name": "lead", "when": { "form_selector": "form#contact" }, "email": { "selector": "input[type=email]" } } ], "consent": "eea_opt_in" } ``` ## Limits and retention Event log 7 days (dedupe window = log; browser and backend rows dedupe separately); visitors 180 days after last seen; click ids used for 90 days; preview log 48 h (500 entries per token); tag stats and coverage 30 days (1000 pages). Imports: 2 MB. Server events: 100 per request. /collect body 64 KB. Preview tokens up to 24 h. Destination answers: 64 KB read. Scan: 6 pages, 1 MB per page, 3 redirects. Optional deployment vars (safe defaults in code; "0" turns a cap off; each also reads UNCLAIMED_ for accounts no person has claimed): MAX_DESTINATIONS_PER_CONTAINER (default 10), MAX_VERSIONS_PER_CONTAINER (default 50), MAX_DRAFT_BYTES (default 524288), MAX_CONTAINERS_PER_ACCOUNT (unset = no cap), MAX_TAGS_BYTES_PER_ACCOUNT (default 20971520), MAX_CUSTOM_CODE_BYTES (unset = 50 KB per tag only), ALLOW_CUSTOM_CODE / UNCLAIMED_ALLOW_CUSTOM_CODE (default true / false), MAX_DELIVERIES_PER_CONTAINER_PER_DAY, MAX_DELIVERIES_PER_ACCOUNT_PER_DAY, MAX_DELIVERIES_PER_DAY (platform-wide; daily budgets, unset = off, counters only go up), MAX_EVENTS_PER_CONTAINER_PER_DAY (browser hits and backend events each; unset = off), MAX_EVENTS_PER_ACCOUNT_PER_DAY (the same summed over an account's containers), MAX_EVENTS_PER_DAY (platform-wide; unclaimed accounts stop at UNCLAIMED_MAX_EVENTS_PER_DAY on the same counter; both unset = off, counted up to a minute behind, counters only go up: deleting containers frees nothing), MAX_VISITORS_PER_CONTAINER (default 250000, least recently seen evicted), MAX_ENVIRONMENTS_PER_CONTAINER (default 5), MAX_LOOKUPS_PER_CONTAINER (default 10), MAX_LOOKUP_ROWS (default 10000), MAX_LOOKUP_BYTES (default 1048576, at most 1.5 MB), MAX_CONTAINER_DB_BYTES (default 1073741824), CIRCUIT_BREAKER_FAILURES (default 20), CIRCUIT_BREAKER_MINUTES (default 60). GET /v1/containers/:id shows the caps that apply and today's usage.