Start a draft agent (spends credits)

Starts a DRAFT agent and SPENDS CREDITS. It creates the agent's results list, checks and deducts the balance, sets up the provider subscriptions and kicks off the first run; the agent moves through processing to active (a scrape stays processing until the scrape finishes). Only drafts can be activated: there is no resume in this API, so a started, paused, expired or failed agent answers 409 AGENT_NOT_A_DRAFT — to restart a paused agent, duplicate it and activate the copy. Nothing is created or spent when the draft's expirationDate is not in the future (422 VALIDATION_FAILED), its name is already taken (409 LIST_NAME_TAKEN) or the balance is short (402 INSUFFICIENT_CREDITS). Any OTHER reason a config cannot be started (a source list with nothing to watch, a plan limit, a field the type's schema refuses) is not classified at activation time and answers 500 UNEXPECTED_ERROR: create the agent with start: true instead, which reports those properly. Answers 202 with the agent as GET returns it; keep polling GET /business/agents/{agentId} until status settles.

Errors:

• 404 AGENT_NOT_FOUND — No agent with this id belongs to the token owner. A deleted agent and another user's agent answer identically.
• 409 AGENT_NOT_A_DRAFT — The agent is not a draft (status is not initializing): it was already started, or is paused, expired or failed. Only drafts are editable and activatable — duplicate the agent and work on the copy.
• 409 LIST_NAME_TAKEN — listName is already used by one of your lists or agents. Pick another name.
• 402 INSUFFICIENT_CREDITS — The workspace does not have enough credits to start this agent. Nothing was created or spent.
• 409 AGENT_CONFIG_MISSING — The draft carries no stored config to work from (a legacy draft saved before configs were persisted). Create the agent again.
• 409 AGENT_TYPE_UNSUPPORTED — The agent is of a legacy kind this API can no longer edit or activate; its type reads as null.
• 422 VALIDATION_FAILED — The activation was rejected by validation: the draft's expirationDate is not in the future (fix it with PATCH, or duplicate the agent and set a new date), or the request itself failed this endpoint's validation (agentId must be a 24-character hex id). No other config problem is reported here: see the 500 entry.
• 422 AGENT_SIGNAL_REJECTED — web-monitor only: the search provider refused the prompt as a searchable signal. Rewrite the prompt rather than retrying it.
• 429 RATE_LIMITED — The agents bucket is exhausted: 30 requests per minute or 2,000 per day per token owner, shared by every /business/agents operation (a 429 raised by the agents service is relayed with this code too). Retry after the Retry-After header.
• 500 UNEXPECTED_ERROR — The agents service failed (5xx, refused service credential, or a timeout after 60s) or the rate limiter was unavailable. A config the activation cannot accept for any reason other than the expiry rule (a source list with nothing to watch, a plan limit, a field the type's schema refuses) also lands here, because the agents service does not classify those at activation time. Retry later; quote request_id to support.

Requires one of the following token scopes: agents.