> ## Documentation Index > Fetch the complete documentation index at: https://docs.dimilinks.com/llms.txt > Use this file to discover all available pages before exploring further. # Model groups & pricing > DimiLinks exposes models through groups, and the group directly determines the billing multiplier. Models on DimiLinks belong to different groups, and the selected group directly determines the final cost. The following constraints apply before a request can run: * Each model is available only in a fixed set of groups. For example, `claude-opus-4-8` is available only in Claude groups; the `default` group cannot run Claude. * Your API key has its own set of available groups. That set must intersect the target model's available groups for the request to succeed. * You cannot extrapolate the cost of the same prompt linearly across models or groups. Billing uses "official price × model multiplier × group multiplier," and combinations may differ by dozens of times. > Do not hardcode multipliers. Groups and prices may change at any time. Treat the `GET /api/pricing` response as the runtime source of truth. ## Authoritative endpoint ```bash theme={null} curl https://dimilinks.com/api/pricing ``` This public endpoint requires no authentication and returns all live groups, public group descriptions, models, and multipliers: ```json theme={null} { "success": true, "pricing_version": "a42d372ccf0b5dd13ecf71203521f9d2", "group_ratio": { "default": 1, "open ai 特价": 0.5, "claude 特价": 0.3, "claude-max": 0.8, "gpt-image-2": 1 }, "usable_group": { "default": "", "open ai 特价": "open ai 自有号池", "claude 特价": "claude 自有号池", "claude-max": "claude 满血渠道", "gpt-image-2": "" }, "auto_groups": [], "supported_endpoint": { "openai": { "path": "/v1/chat/completions", "method": "POST" }, "anthropic": { "path": "/v1/messages", "method": "POST" }, "image_generation": { "path": "/v1/images/generations", "method": "POST" }, "image_edits": { "path": "/v1/images/edits", "method": "POST" } }, "data": [ { "model_name": "gpt-5.5", "enable_groups": ["open ai 特价", "default"], "model_ratio": 2.5, "completion_ratio": 6, "cache_ratio": 0.1, "quota_type": 0, "model_price": 0, "supported_endpoint_types": ["openai"] }, { "model_name": "claude-opus-4-8", "enable_groups": ["claude 特价", "claude-max"], "model_ratio": 2.5, "completion_ratio": 5, "cache_ratio": 0.1, "quota_type": 0, "model_price": 0, "supported_endpoint_types": ["anthropic", "openai"] }, { "model_name": "gpt-image-2", "enable_groups": ["gpt-image-2", "default"], "model_ratio": 0, "completion_ratio": 0, "cache_ratio": null, "quota_type": 1, "model_price": 0.08, "resolution_options": [ { "resolution": "1k", "model_price": 0.08, "max_n": 1 }, { "resolution": "2k", "model_price": 0.15, "max_n": 4 }, { "resolution": "4k", "model_price": 0.30, "max_n": 4 } ], "supported_endpoint_types": ["image_generation", "image_edits"] } ] } ``` ## Field definitions | Field | Meaning | | ------------------------- | ------------------------------------------------------------------------------------------------------------------------------------ | | `group_ratio` | Multiplier map for all current groups; the sole authoritative source | | `usable_group` | Public descriptions for groups, suitable for documentation or UI display | | `auto_groups` | The server's allowlist for automatic groups; only groups listed here may be resolved to a specific model through automatic selection | | `data[].enable_groups` | Groups supported by the model; the request must match at least one | | `data[].model_ratio` | Input-token multiplier relative to the official baseline | | `data[].completion_ratio` | Output-token multiplier, applied as a multiple of `model_ratio` | | `data[].cache_ratio` | Multiplier for cache-hit input; `null` means the model does not distinguish cached input | | `data[].quota_type` | `0` for token-based billing; `1` for per-request billing | | `data[].model_price` | Price per request when `quota_type=1` | | `pricing_version` | Billing snapshot version, used as a client cache key; retrieve fresh data when it changes | ## How callers select a group There are two ways to select a group in a request: 1. **Omit `group` (recommended):** The server calculates "API key groups ∩ model `enable_groups`," then selects one using `auto_groups` and internal priority. This default workflow is sufficient for most callers. 2. **Pass `group` explicitly:** Add a value such as `"group": "claude 特价"` to the request body. The group must belong to both the API key's available groups and the model's `enable_groups`; otherwise, the API returns `403 model_not_allowed`. ```bash theme={null} curl https://dimilinks.com/v1/chat/completions \ -H "Authorization: Bearer $DIMILINKS_API_KEY" \ -H "Content-Type: application/json" \ -d '{ "model": "claude-opus-4-8", "messages": [{"role": "user", "content": "Hello"}], "group": "claude 特价" }' ``` Specify `group` only when one API key has multiple eligible target groups and your application must consistently use one of them. ## Billing formulas For token-billed models (`quota_type = 0`): ```text theme={null} input_cost = input_tokens × model_ratio × group_ratio output_cost = output_tokens × model_ratio × completion_ratio × group_ratio cached_cost = cached_input_tokens × model_ratio × cache_ratio × group_ratio (enabled when cache_ratio is not null) total_cost = input_cost + output_cost + cached_cost ``` For per-request models (`quota_type = 1`): ```text theme={null} total_cost = model_price × group_ratio × n ``` `n` is the number of images or videos actually produced by the task. For image endpoints, it is the `n` field in the request body. ## Cost examples **`claude-opus-4-8` in the `claude 特价` group**, with 1K input tokens and 500 output tokens: * `model_ratio = 2.5`, `completion_ratio = 5`, `group_ratio = 0.3` * `input = 1000 × 2.5 × 0.3 = 750` * `output = 500 × 2.5 × 5 × 0.3 = 1875` * `total ≈ 2625` in internal system quota, converted to display currency using the account's `quota_per_unit` **Comparing `gpt-5.5` in the `default` and `open ai 特价` groups:** * `default`: `group_ratio = 1`; the full `model_ratio 2.5` × `completion_ratio 6` calculation applies. * `open ai 特价`: `group_ratio = 0.5`; the final cost is half the cost in the `default` group. **One asynchronous 2K image from `gpt-image-2`:** * The 2K tier has `model_price = 0.15`; `group_ratio` is either `gpt-image-2 = 1` or `default = 1`, so the request costs `0.15`. Read the separate `resolution_options` values for the 1K and 4K tiers instead of applying the 2K price. ## Engineering recommendations * Retrieve `GET /api/pricing` at startup and build a `model_name → { enable_groups, model_ratio, completion_ratio, cache_ratio, quota_type, model_price }` index. Use `pricing_version` as the cache key. * When showing available groups for a model in the UI, read `data[].enable_groups` and the `usable_group` descriptions directly instead of maintaining a separate hardcoded map. * Cost estimates must account for all four values: `model_ratio`, `completion_ratio`, `cache_ratio`, and `group_ratio`. Omitting any of them produces an inaccurate estimate. * When you see `403 model_not_allowed`, first check whether the API key's available groups cover the target model's `enable_groups`. As a temporary workaround, set `group` explicitly to a group the current key actually has.