fix(pmax): make create_pmax_campaign work + add asset group linking and signals

.gitignore

@@ -4,3 +4,5 @@ credentials.json
 .envrc
 .claude
 dogfood-output/
+
+__pycache__/

CHANGELOG.md

@@ -9,6 +9,39 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 
+- `link_asset_to_asset_group`: link an existing asset to a Performance Max
+  asset group via `assetGroupAssetOperation.create`. `upload_image_asset` only
+  ever created the asset — nothing attached it, so uploaded images sat unused
+  in the account's asset library. A PMax asset group without a
+  `MARKETING_IMAGE`, `SQUARE_MARKETING_IMAGE` and `LOGO` is "Not eligible" and
+  never serves, so this is the step that makes an asset group deliverable. The
+  field type is validated client-side against the 11 types PMax accepts, since
+  the API error for a bad one is opaque.
+- `add_asset_group_signal`: add search themes and/or audience signals to a
+  Performance Max asset group via `assetGroupSignalOperation.create`. PMax does
+  not take audiences as campaign criteria — `add_audience_targeting` writes a
+  `campaignCriterion`, which the API rejects for a PMax campaign. Accepts
+  search themes, audience IDs, or both, and enforces the 80-character search
+  theme limit before the request goes out.
+- `scripts/gads_mutate.py`: send a `googleAds:mutate` payload and print
+  Google's full error tree, with `--check` for `validateOnly`. The server
+  collapses API failures to "Request contains an invalid argument", which hides
+  the field-level reason that actually explains a rejected mutate.
+
+### Fixed
+
+- `create_pmax_campaign` now sets `campaign_budget.explicitly_shared = false`.
+  Budgets default to shared server-side, and Performance Max rejects a shared
+  budget with `BIDDING_STRATEGY_TYPE_INCOMPATIBLE_WITH_SHARED_BUDGET`.
+  `draft_campaign` got this fix in 5670d2d; the PMax path was missed.
+- `create_pmax_campaign` now sets
+  `campaign.contains_eu_political_advertising = DOES_NOT_CONTAIN_EU_POLITICAL_ADVERTISING`.
+  The field is required on every campaign create, and omitting it failed the
+  entire mutate with `fieldError=REQUIRED`.
+
+  Together these two meant `create_pmax_campaign` could not create any
+  Performance Max campaign — every call failed at `confirm_and_apply`.
+
 - `set_campaign_geo_target_type`: set a campaign's
   `campaign.geo_target_type_setting` — `positive_geo_target_type` and/or
   `negative_geo_target_type` — via a `campaignOperation.update` with a matching

scripts/gads_mutate.py

@@ -0,0 +1,129 @@
+#!/usr/bin/env python3
+"""Run a googleAds:mutate request and print Google's full error detail.
+
+The MCP server collapses API failures to "Request contains an invalid argument",
+which hides the field-level reason. This sends the same payload and prints the
+whole error tree, so a rejected mutate can actually be diagnosed.
+
+Usage:
+    scripts/gads_mutate.py operations.json          # apply
+    scripts/gads_mutate.py operations.json --check  # validate_only, changes nothing
+
+operations.json is the JSON array that goes in "mutateOperations".
+Reads .env from the repo root (same file scripts/mcp-env.sh uses).
+"""
+import json
+import os
+import sys
+import urllib.error
+import urllib.parse
+import urllib.request
+
+REPO = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+API = "https://googleads.googleapis.com/v23"
+
+
+def load_env():
+    env = {}
+    path = os.environ.get("MCP_GOOGLE_ADS_ENV", os.path.join(REPO, ".env"))
+    with open(path) as fh:
+        for line in fh:
+            line = line.strip()
+            if not line or line.startswith("#") or "=" not in line:
+                continue
+            k, _, v = line.partition("=")
+            env[k.strip()] = v.strip().strip('"').strip("'")
+    return env
+
+
+def access_token(env):
+    with open(os.path.expanduser(env["GOOGLE_ADS_CREDENTIALS_PATH"])) as fh:
+        cred = json.load(fh)["installed"]
+    with open(os.path.expanduser(env["GOOGLE_ADS_TOKEN_PATH"])) as fh:
+        refresh = json.load(fh)["refresh_token"]
+    body = urllib.parse.urlencode({
+        "client_id": cred["client_id"],
+        "client_secret": cred["client_secret"],
+        "refresh_token": refresh,
+        "grant_type": "refresh_token",
+    }).encode()
+    req = urllib.request.Request("https://oauth2.googleapis.com/token", data=body)
+    with urllib.request.urlopen(req) as resp:
+        return json.load(resp)["access_token"]
+
+
+def headers(env, token):
+    h = {
+        "Authorization": f"Bearer {token}",
+        "developer-token": env["GOOGLE_ADS_DEVELOPER_TOKEN"],
+        "Content-Type": "application/json",
+    }
+    login = env.get("GOOGLE_ADS_LOGIN_CUSTOMER_ID", "").replace("-", "")
+    if login:
+        h["login-customer-id"] = login
+    return h
+
+
+def mutate(env, token, operations, validate_only=False, customer_id=None):
+    cust = (customer_id or env["GOOGLE_ADS_CUSTOMER_ID"]).replace("-", "")
+    payload = {"mutateOperations": operations, "validateOnly": validate_only}
+    req = urllib.request.Request(
+        f"{API}/customers/{cust}/googleAds:mutate",
+        data=json.dumps(payload).encode(),
+        headers=headers(env, token),
+    )
+    try:
+        with urllib.request.urlopen(req) as resp:
+            return json.load(resp), None
+    except urllib.error.HTTPError as e:
+        return None, json.load(e)
+
+
+def describe(err):
+    """Flatten Google's nested error tree into readable lines."""
+    lines = []
+    for detail in err.get("error", {}).get("details", []):
+        for item in detail.get("errors", []):
+            code = item.get("errorCode", {})
+            code_str = ", ".join(f"{k}={v}" for k, v in code.items())
+            loc = item.get("location", {})
+            path = ".".join(
+                str(f.get("fieldName", f.get("index", "")))
+                for f in loc.get("fieldPathElements", [])
+            )
+            lines.append(f"  [{code_str}] {item.get('message', '')}")
+            if path:
+                lines.append(f"      at: {path}")
+    if not lines:
+        lines.append(f"  {err.get('error', {}).get('message', json.dumps(err))}")
+    return "\n".join(lines)
+
+
+def main():
+    args = [a for a in sys.argv[1:] if not a.startswith("--")]
+    validate_only = "--check" in sys.argv
+    if not args:
+        print(__doc__)
+        return 2
+
+    with open(args[0]) as fh:
+        operations = json.load(fh)
+
+    env = load_env()
+    token = access_token(env)
+    cid = os.environ.get("GADS_CUSTOMER_ID")
+    result, err = mutate(env, token, operations, validate_only, cid)
+
+    if err:
+        print(f"FAILED ({'validate' if validate_only else 'apply'}):", file=sys.stderr)
+        print(describe(err), file=sys.stderr)
+        return 1
+
+    print(f"OK ({'validated' if validate_only else 'applied'}) "
+          f"{len(operations)} operation(s)")
+    print(json.dumps(result, indent=2))
+    return 0
+
+
+if __name__ == "__main__":
+    sys.exit(main())

src/lib.rs

@@ -447,6 +447,34 @@ pub struct UploadTextAssetToolParams {
     pub text_content: String,
 }
 
+/// Parameters for linking an asset to a Performance Max asset group.
+#[derive(Debug, Deserialize, Serialize, JsonSchema)]
+pub struct LinkAssetToAssetGroupToolParams {
+    /// Customer ID (e.g. 123-456-7890). Defaults to configured customer_id.
+    pub customer_id: Option<String>,
+    /// The asset group ID to link the asset to.
+    pub asset_group_id: String,
+    /// The asset ID to link (from upload_image_asset / upload_text_asset).
+    pub asset_id: String,
+    /// Field type: MARKETING_IMAGE, SQUARE_MARKETING_IMAGE, PORTRAIT_MARKETING_IMAGE,
+    /// LOGO, LANDSCAPE_LOGO, YOUTUBE_VIDEO, HEADLINE, DESCRIPTION, LONG_HEADLINE,
+    /// BUSINESS_NAME, CALL_TO_ACTION_SELECTION.
+    pub field_type: String,
+}
+
+/// Parameters for adding signals to a Performance Max asset group.
+#[derive(Debug, Deserialize, Serialize, JsonSchema)]
+pub struct AddAssetGroupSignalToolParams {
+    /// Customer ID (e.g. 123-456-7890). Defaults to configured customer_id.
+    pub customer_id: Option<String>,
+    /// The asset group ID to add signals to.
+    pub asset_group_id: String,
+    /// Search themes (max 80 chars each) telling PMax what queries to look for.
+    pub search_themes: Option<Vec<String>>,
+    /// Audience IDs referencing customers/{cid}/audiences/{id}.
+    pub audience_ids: Option<Vec<String>>,
+}
+
 /// Parameters for setting campaign ad schedule.
 #[derive(Debug, Deserialize, Serialize, JsonSchema)]
 pub struct SetCampaignScheduleToolParams {
@@ -1403,6 +1431,59 @@ impl GoogleAdsMcp {
         }
     }
 
+    #[tool(
+        description = "Link an uploaded asset to a Performance Max asset group. Required for images \
+                       to serve — upload_image_asset alone leaves the asset unattached. Returns a preview."
+    )]
+    async fn link_asset_to_asset_group(
+        &self,
+        Parameters(params): Parameters<LinkAssetToAssetGroupToolParams>,
+    ) -> String {
+        if let Some(err) = self.check_write_allowed() {
+            return err;
+        }
+        let cid = self.resolve_customer_id(params.customer_id.as_deref());
+        let config = self.config.clone();
+
+        match tools::assets::link_asset_to_asset_group(
+            &config,
+            &cid,
+            &params.asset_group_id,
+            &params.asset_id,
+            &params.field_type,
+        ) {
+            Ok(preview) => preview.to_string(),
+            Err(e) => serde_json::json!({"error": e.to_string()}).to_string(),
+        }
+    }
+
+    #[tool(
+        description = "Add search themes and/or audience signals to a Performance Max asset group. \
+                       Use this for PMax audiences — add_audience_targeting writes a campaign \
+                       criterion, which PMax rejects. Returns a preview."
+    )]
+    async fn add_asset_group_signal(
+        &self,
+        Parameters(params): Parameters<AddAssetGroupSignalToolParams>,
+    ) -> String {
+        if let Some(err) = self.check_write_allowed() {
+            return err;
+        }
+        let cid = self.resolve_customer_id(params.customer_id.as_deref());
+        let config = self.config.clone();
+
+        match tools::audiences::add_asset_group_signal(
+            &config,
+            &cid,
+            &params.asset_group_id,
+            &params.search_themes.unwrap_or_default(),
+            &params.audience_ids.unwrap_or_default(),
+        ) {
+            Ok(preview) => preview.to_string(),
+            Err(e) => serde_json::json!({"error": e.to_string()}).to_string(),
+        }
+    }
+
     // ── Phase 5: Scheduling ─────────────────────────────────────────────
 
     #[tool(