Migrate functions connector

<!-- GENERATED FILE — DO NOT EDIT. Canonical source: canonical/skills/migrate-functions-connector/SKILL.md Regenerate with: bash scripts/sync-plugins.sh -->

Context: This plugin is for the Fivetran Connector SDK (CSDK). "CSDK" is shorthand for "Connector SDK".

Migrate a Fivetran Functions Connector to CSDK

FIRST: Read sdk-reference.md from the plugin directory to load SDK rules, operation names, schema constraints, configuration rules, and testing requirements.

Use this workflow to convert an existing Fivetran Functions connector into a Connector SDK project. Functions connector examples and migration references:

• Official docs: https://fivetran.com/docs/connectors/functions
• Public examples: https://github.com/fivetran/functions

When validating the migration workflow itself, use representative examples from the public repository:

• api/aws_lambda/index.js for JavaScript AWS Lambda with request.secrets, request.state, insert, delete, schema, and hasMore.
• softDelete/aws-lambda.py for Python AWS Lambda with top-level softDelete.
• Azure-Function/Pyhton/azure-function.py for Azure Function response wrapping.
• file/csv/aws_lambda/index.js for file parsing behavior.

Step 1: Locate the Source and Target

If the user did not provide a source path, ask for the directory or file containing the Functions connector. Accept AWS Lambda, Azure Functions, Google Cloud Functions, or standalone handler examples.

Find or create the target CSDK project:

• If the current directory already has connector.py, configuration.json, and requirements.txt, migrate in place.
• If no CSDK project exists, ask for the target directory name, then scaffold it with fivetran init before editing files.
• Do not overwrite unrelated files.

Step 2: Inventory the Functions Connector

Read the source code and identify:

• Runtime and platform: AWS Lambda, Azure Functions, Google Cloud Functions, or other.
• Language: Python, JavaScript/Node.js, Java, or other.
• Handler entry point and provider glue.
• Configuration inputs from request.secrets, environment variables, or cloud secret services.
• State inputs from request.state.
• Output shape: insert, delete, softDelete, schema, state, hasMore, and error handling.
• Tables, primary keys, cursor fields, pagination, and incremental sync logic.
• Dependencies and source-specific client libraries.
• Any setup/test behavior separate from sync behavior.
• Source naming quirks and bugs. Preserve table/column/state names unless renaming is clearly intentional, then document the change.

Do not ask the user to paste credentials in chat. Replace real values with placeholders if they appear in source files.

Step 3: Map Functions Concepts to CSDK

Use this mapping:

Functions connector concept	Connector SDK concept
Cloud provider handler	Remove; CSDK uses connector = Connector(update=update, schema=schema)
request.secrets	configuration dict from configuration.json
request.state	state dict passed to update(configuration, state)
Returned schema object	schema(configuration) return list with table, primary_key, optional columns
insert[table] records	op.upsert(table=table, data=record)
delete[table] records	op.delete(table=table, keys={...primary key values...})
softDelete table list	op.truncate(table=table) for each listed table, checkpointed after the safe boundary
Returned state	op.checkpoint(state=new_state)
hasMore: true	Loop inside update() until the page/batch is complete, checkpointing safely
Callback/error response	Raise exceptions and use SDK logging

Function connector delete records are full records in many examples. For CSDK op.delete, pass only the declared primary-key values. Function connector softDelete marks all previously synced rows in a table as deleted. For CSDK, use op.truncate(table=...) only when the Functions connector returned that table in softDelete; do not replace row-level deletes with truncate.

Step 4: Port the Implementation

Edit the CSDK project files:

connector.py

• Keep the scaffolded structure where present: validate_configuration(), schema(), update(), global connector = Connector(...), and if __name__ == "__main__": connector.debug().
• Port source extraction logic into Python helper functions.
• Translate JavaScript/Java Functions code into Python behavior; do not wrap cloud-provider handlers.
• Remove AWS Lambda/Azure/GCP request/response glue.
• Replace request.secrets with configuration.
• Replace request.state with state.
• Emit rows using SDK operations directly. Do not yield operations.
• Call op.checkpoint(state=state) after each safe batch.
• Preserve incremental cursor semantics. If the Function connector used hasMore, implement an internal loop with clear stop conditions.
• Preserve soft-delete semantics with op.delete() where the Function connector populated delete.
• Preserve table-wide soft-delete semantics with op.truncate() where the Function connector populated top-level softDelete.
• Add retry handling for HTTP 429 and transient 5xx responses.
• Keep type hints simple: use dict and list; do not import Dict, Any, or use op.Operation.

configuration.json

• Keep flat string key/value pairs only.
• Include fields needed by the connector, using obvious placeholders only.
• Do not include real credentials from the source Function connector.
• Do not use arrays or nested objects.

requirements.txt

• Include only source-specific dependencies not already available in the CSDK environment.
• Do not include fivetran_connector_sdk.
• Do not include cloud provider serverless runtime packages unless the migrated connector still truly needs them.

README.md

• Explain that this connector was migrated from a Fivetran Functions connector.
• Document configuration fields with placeholders only.
• Direct users to tools/enter_configuration.py for secure configuration entry.

Step 5: Validate the Migration

Check behavior before testing:

• Every table from the Function connector has a CSDK schema entry with a primary key.
• Every insert table maps to op.upsert.
• Every delete table maps to op.delete using primary-key fields only.
• Every softDelete table maps to op.truncate only when the source connector used table-wide soft delete.
• Cursor/state names preserve the original incremental semantics.
• hasMore behavior is represented by an internal pagination loop or by checkpointed progress.
• No cloud-provider handler code is required for local CSDK execution.
• No real credentials are present in source files, README, or chat.

Then follow the secure test flow from test-connector:

• Run the secure runner, not fivetran debug directly.
• If configuration values need to be entered or refreshed, direct the user to run tools/enter_configuration.py in their own terminal.
• Do not inspect or print configuration values.

Step 6: Report Results

Summarize:

• Source Function connector platform/language.
• Tables migrated and primary keys.
• State/cursor mapping.
• Any behavior that changed intentionally.
• Remaining manual checks, especially API credentials, endpoint access, and data parity against the original Function connector.