diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index e0df176..ce0dc18 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -21,7 +21,7 @@ The formal catalog convention is the [Model Parameters convention](docs/model-pa
 3. **Required top-level fields:** `provider`, `authType` (`api_key` or `subscription`), `model`, `params`.
 
 4. **Parameter shape:** each item in `params` has:
-   - `path` (required): snake_case, supports dot notation for nested fields (`thinking.type`).
+   - `path` (required): exact provider API request parameter path; supports dot notation for nested fields (`thinking.type`, `generationConfig.topK`).
    - `type` (required): one of `boolean`, `enum`, `integer`, `number`, `string`.
    - `label` (required): human-readable name (e.g. `"Max tokens"`).
    - `description` (required): one sentence, ≤500 chars.
diff --git a/docs/model-parameters-schema.md b/docs/model-parameters-schema.md
index 7352d8c..d3e5048 100644
--- a/docs/model-parameters-schema.md
+++ b/docs/model-parameters-schema.md
@@ -5,9 +5,10 @@ modelparams.dev to describe the request parameters available for a specific
 provider, auth type, and model.
 
 This catalog is metadata. It describes knobs a consumer can put into an outbound
-model request, such as `temperature`, `top_p`, `max_tokens`, or
-`thinking.type`. It does not describe API transport capabilities, proxy behavior,
-authentication flows, endpoint compatibility, pricing, or UI control types.
+model request, such as `temperature`, `top_p`, `max_tokens`,
+`thinking.type`, or `generationConfig.topK`. It does not describe API transport
+capabilities, proxy behavior, authentication flows, endpoint compatibility,
+pricing, or UI control types.
 
 The public runtime sources are:
 
@@ -49,7 +50,9 @@ Conventions:
   contain dots or colons when the upstream model id does.
 - `authType` is `api_key` or `subscription`.
 - `params` is the non-empty list of parameters for that exact route.
-- `path` is a snake_case dot path into stored params and outbound request params.
+- `path` is the exact provider API request parameter path in dot notation. Use
+  the provider's documented field casing, such as `top_p`,
+  `thinking.budget_tokens`, or `generationConfig.topK`.
 - `stream` is reserved for API-level streaming capability metadata and is not a
   valid MPS parameter path.
 - `type` is the semantic data type, not a UI control kind.
@@ -115,7 +118,7 @@ This means: disable the parameter when `thinking.type` is `adaptive` or
 
 ## Match Values
 
-Each match key is a snake_case dot path. Each match value uses one of:
+Each match key is a provider API request parameter path. Each match value uses one of:
 
 - JSON primitive: string, number, boolean, or null
 - non-empty array of JSON primitives
diff --git a/models/google/gemini-2.5-flash-lite.yaml b/models/google/gemini-2.5-flash-lite.yaml
new file mode 100644
index 0000000..aeb3bf1
--- /dev/null
+++ b/models/google/gemini-2.5-flash-lite.yaml
@@ -0,0 +1,77 @@
+# yaml-language-server: $schema=https://modelparams.dev/api/v1/schema.json
+provider: google
+authType: api_key
+model: gemini-2.5-flash-lite
+params:
+  - path: generationConfig.maxOutputTokens
+    type: integer
+    label: Max output tokens
+    description: Maximum number of tokens to include in a response candidate.
+    range:
+      min: 1
+      max: 65536
+    group: generation_length
+  - path: generationConfig.temperature
+    type: number
+    label: Temperature
+    description: Controls randomness. Lower values make outputs more focused; higher values make them more varied.
+    default: 1
+    range:
+      min: 0
+      max: 2
+      step: 0.1
+    group: sampling
+  - path: generationConfig.topP
+    type: number
+    label: Top P
+    description: Controls nucleus sampling by limiting generation to tokens within the selected cumulative probability.
+    default: 0.95
+    range:
+      min: 0
+      max: 1
+      step: 0.01
+    group: sampling
+  - path: generationConfig.topK
+    type: integer
+    label: Top K
+    description: Limits token sampling to the top K most likely next tokens.
+    default: 64
+    range:
+      min: 1
+    group: sampling
+  - path: generationConfig.seed
+    type: integer
+    label: Seed
+    description: Optional seed used for decoding when reproducible sampling is desired.
+    group: sampling
+  - path: generationConfig.presencePenalty
+    type: number
+    label: Presence penalty
+    description: Penalizes tokens that have already appeared in the response to encourage new vocabulary.
+    group: sampling
+  - path: generationConfig.frequencyPenalty
+    type: number
+    label: Frequency penalty
+    description: Penalizes tokens proportionally to how often they have already appeared in the response.
+    group: sampling
+  - path: generationConfig.thinkingConfig.thinkingBudget
+    type: integer
+    label: Thinking budget
+    description: Number of thinking tokens Gemini should use; -1 uses dynamic thinking, 0 disables thinking, and fixed budgets start at 512 tokens.
+    default: 0
+    group: reasoning
+  - path: generationConfig.thinkingConfig.includeThoughts
+    type: boolean
+    label: Include thoughts
+    description: Controls whether Gemini returns available thought summaries in the response parts.
+    default: false
+    group: reasoning
+  - path: generationConfig.responseMimeType
+    type: enum
+    label: Response MIME type
+    description: MIME type for generated text candidates.
+    default: text/plain
+    values:
+      - text/plain
+      - application/json
+    group: output_format
diff --git a/models/google/gemini-2.5-flash.yaml b/models/google/gemini-2.5-flash.yaml
new file mode 100644
index 0000000..bfe07ff
--- /dev/null
+++ b/models/google/gemini-2.5-flash.yaml
@@ -0,0 +1,80 @@
+# yaml-language-server: $schema=https://modelparams.dev/api/v1/schema.json
+provider: google
+authType: api_key
+model: gemini-2.5-flash
+params:
+  - path: generationConfig.maxOutputTokens
+    type: integer
+    label: Max output tokens
+    description: Maximum number of tokens to include in a response candidate.
+    range:
+      min: 1
+      max: 65536
+    group: generation_length
+  - path: generationConfig.temperature
+    type: number
+    label: Temperature
+    description: Controls randomness. Lower values make outputs more focused; higher values make them more varied.
+    default: 1
+    range:
+      min: 0
+      max: 2
+      step: 0.1
+    group: sampling
+  - path: generationConfig.topP
+    type: number
+    label: Top P
+    description: Controls nucleus sampling by limiting generation to tokens within the selected cumulative probability.
+    default: 0.95
+    range:
+      min: 0
+      max: 1
+      step: 0.01
+    group: sampling
+  - path: generationConfig.topK
+    type: integer
+    label: Top K
+    description: Limits token sampling to the top K most likely next tokens.
+    default: 64
+    range:
+      min: 1
+    group: sampling
+  - path: generationConfig.seed
+    type: integer
+    label: Seed
+    description: Optional seed used for decoding when reproducible sampling is desired.
+    group: sampling
+  - path: generationConfig.presencePenalty
+    type: number
+    label: Presence penalty
+    description: Penalizes tokens that have already appeared in the response to encourage new vocabulary.
+    group: sampling
+  - path: generationConfig.frequencyPenalty
+    type: number
+    label: Frequency penalty
+    description: Penalizes tokens proportionally to how often they have already appeared in the response.
+    group: sampling
+  - path: generationConfig.thinkingConfig.thinkingBudget
+    type: integer
+    label: Thinking budget
+    description: Number of thinking tokens Gemini should use; 0 disables thinking and -1 uses dynamic thinking.
+    default: -1
+    range:
+      min: -1
+      max: 24576
+    group: reasoning
+  - path: generationConfig.thinkingConfig.includeThoughts
+    type: boolean
+    label: Include thoughts
+    description: Controls whether Gemini returns available thought summaries in the response parts.
+    default: false
+    group: reasoning
+  - path: generationConfig.responseMimeType
+    type: enum
+    label: Response MIME type
+    description: MIME type for generated text candidates.
+    default: text/plain
+    values:
+      - text/plain
+      - application/json
+    group: output_format
diff --git a/models/google/gemini-2.5-pro.yaml b/models/google/gemini-2.5-pro.yaml
new file mode 100644
index 0000000..d7660d8
--- /dev/null
+++ b/models/google/gemini-2.5-pro.yaml
@@ -0,0 +1,79 @@
+# yaml-language-server: $schema=https://modelparams.dev/api/v1/schema.json
+provider: google
+authType: api_key
+model: gemini-2.5-pro
+params:
+  - path: generationConfig.maxOutputTokens
+    type: integer
+    label: Max output tokens
+    description: Maximum number of tokens to include in a response candidate.
+    range:
+      min: 1
+      max: 65536
+    group: generation_length
+  - path: generationConfig.temperature
+    type: number
+    label: Temperature
+    description: Controls randomness. Lower values make outputs more focused; higher values make them more varied.
+    default: 1
+    range:
+      min: 0
+      max: 2
+      step: 0.1
+    group: sampling
+  - path: generationConfig.topP
+    type: number
+    label: Top P
+    description: Controls nucleus sampling by limiting generation to tokens within the selected cumulative probability.
+    default: 0.95
+    range:
+      min: 0
+      max: 1
+      step: 0.01
+    group: sampling
+  - path: generationConfig.topK
+    type: integer
+    label: Top K
+    description: Limits token sampling to the top K most likely next tokens.
+    default: 64
+    range:
+      min: 1
+    group: sampling
+  - path: generationConfig.seed
+    type: integer
+    label: Seed
+    description: Optional seed used for decoding when reproducible sampling is desired.
+    group: sampling
+  - path: generationConfig.presencePenalty
+    type: number
+    label: Presence penalty
+    description: Penalizes tokens that have already appeared in the response to encourage new vocabulary.
+    group: sampling
+  - path: generationConfig.frequencyPenalty
+    type: number
+    label: Frequency penalty
+    description: Penalizes tokens proportionally to how often they have already appeared in the response.
+    group: sampling
+  - path: generationConfig.thinkingConfig.thinkingBudget
+    type: integer
+    label: Thinking budget
+    description: Maximum number of thinking tokens Gemini should use before producing the final answer.
+    range:
+      min: 128
+      max: 32768
+    group: reasoning
+  - path: generationConfig.thinkingConfig.includeThoughts
+    type: boolean
+    label: Include thoughts
+    description: Controls whether Gemini returns available thought summaries in the response parts.
+    default: false
+    group: reasoning
+  - path: generationConfig.responseMimeType
+    type: enum
+    label: Response MIME type
+    description: MIME type for generated text candidates.
+    default: text/plain
+    values:
+      - text/plain
+      - application/json
+    group: output_format
diff --git a/models/google/gemini-3.5-flash.yaml b/models/google/gemini-3.5-flash.yaml
new file mode 100644
index 0000000..27fa32a
--- /dev/null
+++ b/models/google/gemini-3.5-flash.yaml
@@ -0,0 +1,82 @@
+# yaml-language-server: $schema=https://modelparams.dev/api/v1/schema.json
+provider: google
+authType: api_key
+model: gemini-3.5-flash
+params:
+  - path: generationConfig.maxOutputTokens
+    type: integer
+    label: Max output tokens
+    description: Maximum number of tokens to include in a response candidate.
+    range:
+      min: 1
+      max: 65536
+    group: generation_length
+  - path: generationConfig.temperature
+    type: number
+    label: Temperature
+    description: Controls randomness. Lower values make outputs more focused; higher values make them more varied.
+    default: 1
+    range:
+      min: 0
+      max: 2
+      step: 0.1
+    group: sampling
+  - path: generationConfig.topP
+    type: number
+    label: Top P
+    description: Controls nucleus sampling by limiting generation to tokens within the selected cumulative probability.
+    default: 0.95
+    range:
+      min: 0
+      max: 1
+      step: 0.01
+    group: sampling
+  - path: generationConfig.topK
+    type: integer
+    label: Top K
+    description: Limits token sampling to the top K most likely next tokens.
+    default: 64
+    range:
+      min: 1
+    group: sampling
+  - path: generationConfig.seed
+    type: integer
+    label: Seed
+    description: Optional seed used for decoding when reproducible sampling is desired.
+    group: sampling
+  - path: generationConfig.presencePenalty
+    type: number
+    label: Presence penalty
+    description: Penalizes tokens that have already appeared in the response to encourage new vocabulary.
+    group: sampling
+  - path: generationConfig.frequencyPenalty
+    type: number
+    label: Frequency penalty
+    description: Penalizes tokens proportionally to how often they have already appeared in the response.
+    group: sampling
+  - path: generationConfig.thinkingConfig.thinkingLevel
+    type: enum
+    label: Thinking level
+    description: Controls Gemini 3.5 Flash reasoning effort.
+    default: medium
+    values:
+      - minimal
+      - low
+      - medium
+      - high
+    group: reasoning
+  - path: generationConfig.thinkingConfig.includeThoughts
+    type: boolean
+    label: Include thoughts
+    description: Controls whether Gemini returns available thought summaries in the response parts.
+    default: false
+    group: reasoning
+  - path: generationConfig.responseMimeType
+    type: enum
+    label: Response MIME type
+    description: MIME type for generated text candidates.
+    default: text/plain
+    values:
+      - text/plain
+      - application/json
+    group: output_format
diff --git a/src/schema/model.ts b/src/schema/model.ts
index 1203127..731d363 100644
--- a/src/schema/model.ts
+++ b/src/schema/model.ts
@@ -19,7 +19,7 @@ export type ParameterGroup = z.infer<typeof ParameterGroup>;
 
 const PROVIDER_SLUG = /^[a-z0-9][a-z0-9-]*$/;
 const MODEL_ID = /^[a-z0-9][a-z0-9._:-]*$/;
-const PARAM_PATH = /^[a-z][a-z0-9_]*(\.[a-z][a-z0-9_]*)*$/;
+const PARAM_PATH = /^[A-Za-z][A-Za-z0-9_]*(\.[A-Za-z][A-Za-z0-9_]*)*$/;
 const BLOCKED_PARAM_PATHS = new Set(["stream"]);
 
 export const Range = z
@@ -48,7 +48,7 @@ const ApplicabilityValue = z.union([JsonPrimitive, JsonPrimitiveArray, Applicabi
 
 export const ApplicabilityRule = z
   .record(
-    z.string().regex(PARAM_PATH, "applicability keys must be snake_case dot paths"),
+    z.string().regex(PARAM_PATH, "applicability keys must be provider API dot paths"),
     ApplicabilityValue,
   )
   .refine((rule) => Object.keys(rule).length > 0, {
@@ -73,7 +73,7 @@ const baseParameterShape = {
   path: z
     .string()
     .min(1)
-    .regex(PARAM_PATH, "param path must be snake_case dot-notation (e.g. `thinking.type`)"),
+    .regex(PARAM_PATH, "param path must be a provider API dot path (e.g. `thinking.type`)"),
   label: z.string().min(1).max(80),
   description: z.string().min(1).max(500),
   group: ParameterGroup,
diff --git a/tests/schema.test.ts b/tests/schema.test.ts
index a197833..54947c9 100644
--- a/tests/schema.test.ts
+++ b/tests/schema.test.ts
@@ -99,6 +99,25 @@ describe("Model schema", () => {
     expect(result.success).toBe(false);
   });
 
+  it("accepts provider API paths with native casing", () => {
+    const result = Model.safeParse({
+      ...VALID_MODEL,
+      provider: "google",
+      model: "gemini-3.5-flash",
+      params: [
+        {
+          path: "generationConfig.thinkingConfig.thinkingLevel",
+          type: "enum",
+          label: "Thinking level",
+          description: "x",
+          values: ["low", "medium", "high"],
+          group: "reasoning",
+        },
+      ],
+    });
+    expect(result.success).toBe(true);
+  });
+
   it("rejects bad param path", () => {
     const result = Model.safeParse({
       ...VALID_MODEL,
@@ -180,6 +199,27 @@ describe("Model schema", () => {
     expect(result.success).toBe(true);
   });
 
+  it("accepts provider API paths in applicability rules", () => {
+    const result = Model.safeParse({
+      ...VALID_MODEL,
+      provider: "google",
+      model: "gemini-3.5-flash",
+      params: [
+        {
+          path: "generationConfig.thinkingConfig.includeThoughts",
+          type: "boolean",
+          label: "Include thoughts",
+          description: "x",
+          group: "reasoning",
+          applicability: {
+            except: { "generationConfig.thinkingConfig.thinkingLevel": "minimal" },
+          },
+        },
+      ],
+    });
+    expect(result.success).toBe(true);
+  });
+
   it("rejects unknown applicability operators", () => {
     const result = Model.safeParse({
       ...VALID_MODEL,