> ## Documentation Index
> Fetch the complete documentation index at: https://dialnexa.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.
# Get LLM Details
> Fetch one LLM catalog entry by ID.
Read only
**Recommended.** This endpoint is part of the public `/v1` API reference and is the supported path for new integrations. See the [migration guide](/docs/api-reference/v1/migrating-to-v1) for versioning guidance.
Returns the full record for a single LLM in DialNexa's supported model catalogue. The response includes the model's stable `id`, the upstream `provider` (for example OpenAI, Anthropic, Google, or a hosted open-weights model), the display `name`, the context window size, and which conversational features are supported (such as function calling and JSON mode).
## When to use this
Use this endpoint when you have an `llm_id` saved on an agent configuration or in your own database and you need to resolve it into a human-readable label, confirm the model is still active, or check what features the model supports before sending an agent update.
* **Agent build UIs** typically fetch this when rendering the LLM selection for an already-saved agent so the dropdown can display the correct provider, name, and capability badges.
* **Migration tooling** that retires a deprecated model uses this to confirm the target model still exists before bulk-updating agents.
* **Cost-aware dashboards** read the provider and tier from this endpoint to attribute spend per model in internal reports.
If you need the full list of available LLMs, call [List LLMs](/docs/api-reference/v1/llms/list) instead. That endpoint is the canonical catalogue and is paginated.
## Path parameters
| Parameter | Description |
| --------- | ------------------------------------ |
| `id` | The LLM ID, for example `llm_gpt4o`. |
## Errors
* `404 Not Found` is returned when the `id` does not match a supported LLM. This usually means the model has been deprecated and removed, or the ID was mistyped.
* `401 Unauthorized` is returned when the API key is missing, malformed, or revoked. See [Authentication](/docs/api-reference/authentication).
## Related endpoints
* [List LLMs](/docs/api-reference/v1/llms/list): fetch every LLM the platform currently supports.
* [Update Agent](/docs/api-reference/v1/agents/update): change the LLM assigned to an existing agent.
* [LLMs and conversation behavior](/docs/voice-ai/llms-and-conversation-behavior): guidance on choosing an LLM for your use case.
## OpenAPI
````yaml GET /v1/llms/{id}
openapi: 3.0.0
info:
title: DialNexa API
description: >-
Public REST API for the DialNexa voice AI platform. Versioned endpoints are
under /v1; unversioned endpoints are legacy and deprecated.
version: 1.0.0
servers:
- url: https://api.dialnexa.com
description: DialNexa production API
security:
- bearer: []
tags:
- name: API Keys
- name: Agent Functions
- name: Agents V1
- name: Agents2
- name: Batch Calls
- name: Batch Calls V1
- name: Call Logs
- name: Calls
- name: Calls V1
- name: Campaign Leads
- name: Campaigns
- name: External Webhooks
- name: Knowledge Base
- name: Knowledge Base V1
- name: LLMs
- name: LLMs V1
- name: Languages
- name: Languages V1
- name: Organization Phone Numbers
- name: Organization Phone Numbers V1
- name: Phone Number Pricing
- name: Phone Number Pricing V1
- name: Transcribers
- name: Transcribers V1
- name: User Webhooks
- name: User Webhooks V1
- name: V1
- name: Voices
- name: Voices V1
- name: Webcall
- name: Workflow Leads
- name: Workflow Leads V1
- name: Workflows
- name: Workflows V1
paths:
/v1/llms/{id}:
get:
tags:
- LLMs
- LLMs V1
- V1
summary: Get LLM Details
description: Returns one large language model catalog record by ID.
operationId: LlmsV1Controller_findById
parameters:
- name: id
required: true
in: path
description: LLM ID
schema:
example: llm_abc123
type: string
responses:
'200':
description: LLM returned successfully.
content:
application/json:
schema:
$ref: '#/components/schemas/Llm'
examples:
success:
summary: Successful response
value:
id: llm_A1B2C3D4E5F6G7
name: GPT-4.1 Mini
provider: openai
supports_structured_output: true
'400':
description: Invalid catalog ID format.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
error:
summary: 400 Bad Request
value:
statusCode: 400
message: Invalid catalog ID format
error: Bad Request
'401':
description: Unauthorized.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
error:
summary: 401 Unauthorized
value:
statusCode: 401
message: API key is missing or invalid
error: Unauthorized
'403':
description: Forbidden - API key does not have access to this organization.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
error:
summary: 403 Forbidden
value:
statusCode: 403
message: You do not have permission to access this resource
error: Forbidden
'404':
description: LLM not found.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
error:
summary: 404 Not Found
value:
statusCode: 404
message: LLM not found
error: Not Found
'500':
description: Internal server error.
content:
application/json:
schema:
$ref: '#/components/schemas/ErrorResponse'
examples:
error:
summary: 500 Internal Server Error
value:
statusCode: 500
message: Internal server error
error: Internal Server Error
security:
- bearer: []
components:
schemas:
Llm:
type: object
properties:
id:
type: string
example: llm_abc123
description: Signed LLM ID
required:
- id
ErrorResponse:
type: object
properties:
statusCode:
type: integer
example: 400
message:
oneOf:
- type: string
- type: array
items:
type: string
example: phone_number must be a valid E.164 phone number
error:
type: string
example: Bad Request
required:
- statusCode
- message
- error
securitySchemes:
bearer:
scheme: bearer
bearerFormat: JWT
type: http
````