Reviewed and documented merged PRPublic

>gh pr view 1051 --json title,body,comments,commits,files,author,state,mergedAt,baseRefName,headRefName,labels

{"author":{"id":"MDQ6VXNlcjIwNzEzNjU2","is_bot":false,"login":"ben-vargas","name":"Ben Vargas"},"baseRefName":"main","body":"Adds `vercelGatewayRouting` support to the OpenAI completions provider, mirroring the existing `openRouterRouting` pattern. This allows custom models routed through the Vercel AI Gateway to specify provider preferences via `only` and `order` fields.\n\n## Changes\n\n**packages/ai**\n- `types.ts`: Added `VercelGatewayRouting` interface (`only`, `order` string arrays) and `vercelGatewayRouting` field to `OpenAICompletionsCompat`\n- `openai-completions.ts`: Detect `ai-gateway.vercel.sh` base URLs and inject routing into request params, with auto-detection from built-in gateway models\n- `test/openai-completions-tool-result-images.test.ts`: Added `vercelGatewayRouting` to compat fixture\n\n**packages/coding-agent**\n- `model-registry.ts`: Added `VercelGatewayRoutingSchema` and wired it into `OpenAICompletionsCompatSchema`\n- `docs/models.md`: Documented `vercelGatewayRouting` compat field with example\n\n## How it works\n\nWhen a model's `baseUrl` contains `ai-gateway.vercel.sh` and `compat.vercelGatewayRouting` is set, the provider injects a `provider` field into the request body with the routing preferences. This matches how OpenRouter routing already works — same pattern, different gateway.\n\nFor built-in Vercel AI Gateway models, routing is auto-detected from the model's `compat` metadata. Custom models can override via `models.json`.\n\n## Disclaimer\n\nThis was coded by Opus and reviewed by GPT-5.2 Codex. Consider this a proposal — no issue if it gets reworked as the maintainer sees fit.","comments":[],"commits":[{"authoredDate":"2026-01-29T02:18:05Z","authors":[{"email":"[REDACTED]","id":"MDQ6VXNlcjIwNzEzNjU2","login":"ben-vargas","name":"Ben Vargas"}],"committedDate":"2026-01-29T03:38:42Z","messageBody":"Add vercelGatewayRouting to OpenAICompletionsCompat, parallel to\nopenRouterRouting. When a model targets ai-gateway.vercel.sh and has\nvercelGatewayRouting configured, the openai-completions provider passes\nproviderOptions.gateway with only/order in the request body.\n\nChanges:\n- types.ts: VercelGatewayRouting interface + field on OpenAICompletionsCompat\n- openai-completions.ts: buildParams passes providerOptions.gateway,\n  detectCompat/getCompat include the new field\n- model-registry.ts: VercelGatewayRoutingSchema for models.json validation\n- test: updated Required<OpenAICompletionsCompat> in test fixture","messageHeadline":"feat(ai): add Vercel AI Gateway routing support","oid":"59bb037e50aa3d5a6c833a2e79524b113cec2972"},{"authoredDate":"2026-01-29T04:14:58Z","authors":[{"email":"[REDACTED]","id":"MDQ6VXNlcjIwNzEzNjU2","login":"ben-vargas","name":"Ben Vargas"}],"committedDate":"2026-01-29T04:14:58Z","messageBody":"…tation","messageHeadline":"docs(coding-agent): add vercelGatewayRouting to custom models documen…","oid":"de38eaa131a1efa203b99608a098f628d7255ced"}],"files":[{"path":"packages/ai/src/providers/openai-completions.ts","additions":13,"deletions":0},{"path":"packages/ai/src/types.ts","additions":14,"deletions":0},{"path":"packages/ai/test/openai-completions-tool-result-images.test.ts","additions":1,"deletions":0},{"path":"packages/coding-agent/docs/models.md","additions":32,"deletions":0},{"path":"packages/coding-agent/src/core/model-registry.ts","additions":7,"deletions":0}],"headRefName":"feat-vercel-gateway-routing","labels":[],"mergedAt":"2026-01-30T00:44:52Z","state":"MERGED","title":"feat(ai): add Vercel AI Gateway routing support"}

>gh pr diff 1051

diff --git a/packages/ai/src/providers/openai-completions.ts b/packages/ai/src/providers/openai-completions.ts
index d777c116b..2fcf86fd5 100644
--- a/packages/ai/src/providers/openai-completions.ts
+++ b/packages/ai/src/providers/openai-completions.ts
@@ -452,6 +452,17 @@ function buildParams(model: Model<"openai-completions">, context: Context, optio
 		(params as any).provider = model.compat.openRouterRouting;
 	}
 
+	// Vercel AI Gateway provider routing preferences
+	if (model.baseUrl.includes("ai-gateway.vercel.sh") && model.compat?.vercelGatewayRouting) {
+		const routing = model.compat.vercelGatewayRouting;
+		if (routing.only || routing.order) {
+			const gatewayOptions: Record<string, string[]> = {};
+			if (routing.only) gatewayOptions.only = routing.only;
+			if (routing.order) gatewayOptions.order = routing.order;
+			(params as any).providerOptions = { gateway: gatewayOptions };
+		}
+	}
+
 	return params;
 }
 
@@ -797,6 +808,7 @@ function detectCompat(model: Model<"openai-completions">): Required<OpenAIComple
 		requiresMistralToolIds: isMistral,
 		thinkingFormat: isZai ? "zai" : "openai",
 		openRouterRouting: {},
+		vercelGatewayRouting: {},
 	};
 }
 
@@ -821,5 +833,6 @@ function getCompat(model: Model<"openai-completions">): Required<OpenAICompletio
 		requiresMistralToolIds: model.compat.requiresMistralToolIds ?? detected.requiresMistralToolIds,
 		thinkingFormat: model.compat.thinkingFormat ?? detected.thinkingFormat,
 		openRouterRouting: model.compat.openRouterRouting ?? {},
+		vercelGatewayRouting: model.compat.vercelGatewayRouting ?? detected.vercelGatewayRouting,
 	};
 }
diff --git a/packages/ai/src/types.ts b/packages/ai/src/types.ts
index 5d8eb2665..3b9822f25 100644
--- a/packages/ai/src/types.ts
+++ b/packages/ai/src/types.ts
@@ -218,6 +218,8 @@ export interface OpenAICompletionsCompat {
 	thinkingFormat?: "openai" | "zai";
 	/** OpenRouter-specific routing preferences. Only used when baseUrl points to OpenRouter. */
 	openRouterRouting?: OpenRouterRouting;
+	/** Vercel AI Gateway routing preferences. Only used when baseUrl points to Vercel AI Gateway. */
+	vercelGatewayRouting?: VercelGatewayRouting;
 }
 
 /** Compatibility settings for OpenAI Responses APIs. */
@@ -237,6 +239,18 @@ export interface OpenRouterRouting {
 	order?: string[];
 }
 
+/**
+ * Vercel AI Gateway routing preferences.
+ * Controls which upstream providers the gateway routes requests to.
+ * @see https://vercel.com/docs/ai-gateway/models-and-providers/provider-options
+ */
+export interface VercelGatewayRouting {
+	/** List of provider slugs to exclusively use for this request (e.g., ["bedrock", "anthropic"]). */
+	only?: string[];
+	/** List of provider slugs to try in order (e.g., ["anthropic", "openai"]). */
+	order?: string[];
+}
+
 // Model interface for the unified model system
 export interface Model<TApi extends Api> {
 	id: string;
diff --git a/packages/ai/test/openai-completions-tool-result-images.test.ts b/packages/ai/test/openai-completions-tool-result-images.test.ts
index 36398f26e..3330e776e 100644
--- a/packages/ai/test/openai-completions-tool-result-images.test.ts
+++ b/packages/ai/test/openai-completions-tool-result-images.test.ts
@@ -31,6 +31,7 @@ const compat: Required<OpenAICompletionsCompat> = {
 	requiresMistralToolIds: false,
 	thinkingFormat: "openai",
 	openRouterRouting: {},
+	vercelGatewayRouting: {},
 };
 
 function buildToolResult(toolCallId: string, timestamp: number): ToolResultMessage {
diff --git a/packages/coding-agent/docs/models.md b/packages/coding-agent/docs/models.md
index dc2391f5f..cad0c06b0 100644
--- a/packages/coding-agent/docs/models.md
+++ b/packages/coding-agent/docs/models.md
@@ -165,6 +165,7 @@ For providers with partial OpenAI compatibility, use the `compat` field:
 | `supportsUsageInStreaming` | Supports `stream_options: { include_usage: true }` (default: `true`) |
 | `maxTokensField` | Use `max_completion_tokens` or `max_tokens` |
 | `openRouterRouting` | OpenRouter routing config passed to OpenRouter for model/provider selection |
+| `vercelGatewayRouting` | Vercel AI Gateway routing config for provider selection (`only`, `order`) |
 
 Example:
 
@@ -191,3 +192,34 @@ Example:
   }
 }
 ```
+
+Vercel AI Gateway example:
+
+```json
+{
+  "providers": {
+    "vercel-ai-gateway": {
+      "baseUrl": "https://ai-gateway.vercel.sh/v1",
+      "apiKey": "AI_GATEWAY_API_KEY",
+      "api": "openai-completions",
+      "models": [
+        {
+          "id": "moonshotai/kimi-k2.5",
+          "name": "Kimi K2.5 (Fireworks via Vercel)",
+          "reasoning": true,
+          "input": ["text", "image"],
+          "cost": { "input": 0.6, "output": 3, "cacheRead": 0, "cacheWrite": 0 },
+          "contextWindow": 262144,
+          "maxTokens": 262144,
+          "compat": {
+            "vercelGatewayRouting": {
+              "only": ["fireworks", "novita"],
+              "order": ["fireworks", "novita"]
+            }
+          }
+        }
+      ]
+    }
+  }
+}
+```
diff --git a/packages/coding-agent/src/core/model-registry.ts b/packages/coding-agent/src/core/model-registry.ts
index 2cd2171a1..50c4c6b06 100644
--- a/packages/coding-agent/src/core/model-registry.ts
+++ b/packages/coding-agent/src/core/model-registry.ts
@@ -31,6 +31,12 @@ const OpenRouterRoutingSchema = Type.Object({
 	order: Type.Optional(Type.Array(Type.String())),
 });
 
+// Schema for Vercel AI Gateway routing preferences
+const VercelGatewayRoutingSchema = Type.Object({
+	only: Type.Optional(Type.Array(Type.String())),
+	order: Type.Optional(Type.Array(Type.String())),
+});
+
 // Schema for OpenAI compatibility settings
 const OpenAICompletionsCompatSchema = Type.Object({
 	supportsStore: Type.Optional(Type.Boolean()),
@@ -44,6 +50,7 @@ const OpenAICompletionsCompatSchema = Type.Object({
 	requiresMistralToolIds: Type.Optional(Type.Boolean()),
 	thinkingFormat: Type.Optional(Type.Union([Type.Literal("openai"), Type.Literal("zai")])),
 	openRouterRouting: Type.Optional(OpenRouterRoutingSchema),
+	vercelGatewayRouting: Type.Optional(VercelGatewayRoutingSchema),
 });
 
 const OpenAIResponsesCompatSchema = Type.Object({

>gh pr view 1051 --json timelineItems --jq '.timelineItems'

Unknown JSON field: "timelineItems"
Available fields:
  additions
  assignees
  author
  autoMergeRequest
  baseRefName
  baseRefOid
  body
  changedFiles
  closed
  closedAt
  closingIssuesReferences
  comments
  commits
  createdAt
  deletions
  files
  fullDatabaseId
  headRefName
  headRefOid
  headRepository
  headRepositoryOwner
  id
  isCrossRepository
  isDraft
  labels
  latestReviews
  maintainerCanModify
  mergeCommit
  mergeStateStatus
  mergeable
  mergedAt
  mergedBy
  milestone
  number
  potentialMergeCommit
  projectCards
  projectItems
  reactionGroups
  reviewDecision
  reviewRequests
  reviews
  state
  statusCheckRollup
  title
  updatedAt
  url


Command exited with code 1

>gh pr view 1051 --json closingIssuesReferences

{"closingIssuesReferences":[]}