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BigQuery UDF Builder

Write, deploy, and debug custom BigQuery functions in SQL, JavaScript, Python, or Cloud Run.

Source Download skill
Repository
google/skills
Stars
21,782
Licence
Apache-2.0
Files
6 files

What it does

Once installed, the agent knows how to build custom functions (called User-Defined Functions) for Google BigQuery, a data warehouse. It helps pick the lightest suitable option (SQL, JavaScript, managed Python, or an external Cloud Run endpoint), writes the code and SQL to create the function, lists the permissions and APIs needed, and helps troubleshoot errors. It also points to reference guides for aggregate functions, library loading, IAM roles and quotas.

Great for

  • Data engineers who need custom string, JSON, or calculation logic inside BigQuery queries
  • Developers calling Google Cloud or external APIs from BigQuery and needing the right connection setup
  • Analysts who know what they want a function to do but not which BigQuery UDF type fits

Skip it if

  • Routine table or dataset management, which the skill says to hand off to a different skill (bigquery-basics), since this one covers functions only
  • BigQuery ML model work or DataFrame client workflows, which are handled by other skills
  • Production deployments without review: the agent generates IAM grants and API enablement commands that change real cloud projects and can incur billing

Try asking

  • “Create a SQL UDF that normalizes phone numbers to international format in my BigQuery dataset”
  • “Write a JavaScript UDF that parses URL query keys and loads a parser library from Cloud Storage”
  • “Set up a Python UDF that calls the Cloud Translation API using a BigQuery connection”
  • “Troubleshoot why my remote function returns a permission error when called from a query”
Step-by-step guide: how to use BigQuery UDF BuilderInstall, first run, examples, tips and FAQs

Install in 3 steps

  1. 1

    Download the skill

    The ZIP contains the 6 original files, the Apache-2.0 licence and an attribution note.

    bigquery-udfs.zip
  2. 2

    Add it to your agent

    Claude Code (all projects)

    mkdir -p ~/.claude/skills && unzip bigquery-udfs.zip -d ~/.claude/skills/

    Claude Code / Agent SDK (this project only)

    mkdir -p .claude/skills && unzip bigquery-udfs.zip -d .claude/skills/

    Claude apps (web/desktop): Settings → Capabilities → Skills → Upload skill, and choose the ZIP.

  3. 3

    Ask for the task

    No special command needed — the agent reads the skill's description and loads it when your request matches. Try one of the prompts above.

Get better results

  • Give the agent your project ID, dataset, and preferred region; it defaults to us-central1 if you do not specify one.
  • Review every gcloud and IAM command before approving it, especially those granting project-level roles to connection service accounts.
  • Ask for the simplest runtime first; the skill recommends SQL or JavaScript before Python or Remote Functions.

What's inside

  • references/attribution.md
  • references/iam-and-quotas.md
  • references/python-udfs.md
  • references/remote-functions.md
  • references/sql-and-js-udfs.md
  • SKILL.md

Redistributed unmodified from google/skills under the Apache-2.0 licence. The assessment was drafted with AI from the skill's files on 2026-10-29. Skills can instruct your agent to run code — read SKILL.md and any scripts before installing.