Get agent by ID

Returns the agent document merged with the resolved config of the active version under `_resolvedConfig`. Non-versioned fields (name, telephonyProductId, allowInboundCall, etc.) sit at the top level; versioned fields (prompt, tools, language, synthesizer, post-call analytics, …) are resolved from the target version and exposed under `_resolvedConfig`. **Previewing a draft or specific version** Pass `?draftId=<id>` to resolve config from a specific draft instead of the active version. Pass `?versionId=<id>` to resolve config from a specific published version. When either param is used, the response includes `_configSource: "draft" | "version" | "active"` indicating which config was resolved. Notable resolved fields in `_resolvedConfig`: - `prompt` — active version's single-prompt text - `tools` — configured tools on the resolved version - `postCallAnalyticsConfig` — disposition metrics + analytics model flags - `modelName` — LLM model name on the resolved version - `defaultLanguage`, `supportedLanguages` — active language config - `firstMessage`, `globalPrompt` — active messaging config - `workflowGraph` — full node graph for `workflow_graph` agents To read prompt + tools alone, use `GET /agent/{id}/workflow` (deprecated for new integrations but still live). To inspect a specific non-active version, use `GET /agent/{id}/versions/{versionId}`. **400 — also used for "not found":** if the agent ID does not exist in the organization, the API returns 400 with `errors: ["No agent found"]` rather than 404.