API Changelog

New Webhook Logs Endpoints

We’ve added two endpoints to manage Webhook Logs programmatically.

Endpoints Added:

• GET /logs — List webhook logs
• GET /logs/:webhook_log_id — Retrieve a webhook log by ID

New Simulations Endpoints

We’ve added a comprehensive set of new endpoints to manage Simulation Cases and Simulation Sessions programmatically.

• Case Management: Create, list, retrieve, update, delete, and generate simulation cases.
• Session Management: Start a simulation and list/retrieve simulation sessions.
• Listings: List simulation cases by agent and list all simulations.

Endpoints Added:

• POST /simulations — Create a simulation case
• GET /simulations — List simulation cases
• GET /simulations/:case_id — Get a simulation case
• PUT /simulations/:case_id — Update a simulation case
• DELETE /simulations/:case_id — Delete a simulation case
• POST /simulations/generate — Generate simulation cases
• GET /simulations/agent/:agent_id — List simulation cases by agent
• POST /simulations/start — Start a simulation
• GET /sessions — List simulation sessions
• GET /sessions/:session_id — Get a simulation session
• GET /simulations/all — List simulation cases
• GET /simulations/:case_id — Get a simulation case

Read more about the feature here: https://docs.synthflow.ai/simulations

Subaccount Update: Import/Return Products

Added support to the update subaccount endpoint to manage importing objects like phone numbers from the parent workspace to subaccounts.

• New optional field operation_type (string): allowed values import, return.
• New optional field products.phone_numbers[].number to specify E.164 numbers to import to or return from the subaccount_id.

• PUT /subaccounts/:subaccount_id — Update a subaccount

New timeout value for custom actions

You can now specify a failure_timeout field when creating or updating a custom action. This allows you to control how long a custom action is allowed to run before it is automatically terminated if the timeout is reached.

Deprecated Language Value

The es language code is no longer supported. Please use es-ES for Spanish when creating or updating agents.

• POST /assistants/ — Create an agent
• PUT /assistants/:model_id/ — Update an agent

Phone books: new API endpoints

New endpoints added:

• POST /phonebooks/ (Create a phone book)
• GET /phonebooks/ (List phone books)
• DELETE /phonebooks/:phone_book_id/ (Delete a phone book)
• POST /phonebooks/:phone_book_id/entries/ (Create a phone book entry)
• DELETE /phonebooks/:phone_book_id/entries/:entry_id (Delete a phone book entry)

GPT-5 is now supported

Added GPT-5 support for agents.

• POST /assistants/ (Create an agent)
• PUT /assistants/:model_id/ (Update an agent)

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 "agent": {
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    "llm": "gpt-5-chat"
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  }

Contacts and Memory stores: new API endpoints

Contacts

New endpoints added:

• POST /contacts/ (Create a contact)
• GET /contacts/ (List contacts)
• GET /contacts/:contact_id/ (Get a contact)
• PATCH /contacts/:contact_id/ (Update a contact)
• DELETE /v2/contacts/:contact_id (Delete a contact)

Memory stores

New endpoints added:

• POST /memory_stores/ (Create a memory store)
• GET /memory_stores/ (List memory stores)
• PATCH /memory_stores/ (Update a memory store)
• DELETE /memory_stores/ (Delete a memory store)
• GET /memory_stores/:memory_store_id/ (Get memory stores by contact ID)
• POST /memory_stores/:memory_store_id/assistants/:assistant_id/attach/ (Attach a memory store to an agent)
• POST /memory_stores/:memory_store_id/assistants/:assistant_id/detach/ (Detach a memory store from an agent)
• POST /memory_stores/:memory_store_id/contacts/:contact_id/memory_data (Get data for a specific memory store and contact)
• POST /memory_stores/:memory_store_id/contacts/:contact_id/attach (Attach a contact to a memory store)
• POST /memory_stores/:memory_store_id/contacts/:contact_id/detach (Detach a contact from a memory store)