Models/Config: default missing Anthropic model api fields

CHANGELOG.md

@@ -31,6 +31,7 @@ Docs: https://docs.openclaw.ai
 - Agents/Fallbacks: treat JSON payloads with `type: "api_error"` + `"Internal server error"` as transient failover errors so Anthropic 500-style failures trigger model fallback. (#23193) Thanks @jarvis-lane.
 - Agents/Diagnostics: include resolved lifecycle error text in `embedded run agent end` warnings so UI/TUI “Connection error” runs expose actionable provider failure reasons in gateway logs. (#23054) Thanks @Raize.
 - Plugins/Hooks: run legacy `before_agent_start` once per agent turn and reuse that result across model-resolve and prompt-build compatibility paths, preventing duplicate hook side effects (for example duplicate external API calls). (#23289) Thanks @ksato8710.
+- Models/Config: default missing Anthropic provider/model `api` fields to `anthropic-messages` during config validation so custom relay model entries are preserved instead of being dropped by runtime model registry validation. (#23332) Thanks @bigbigmonkey123.
 - Gateway/Pairing: treat operator.admin pairing tokens as satisfying operator.write requests so legacy devices stop looping through scope-upgrade prompts introduced in 2026.2.19. (#23125, #23006) Thanks @vignesh07.
 - Gateway/Pairing: treat `operator.admin` as satisfying other `operator.*` scope checks during device-auth verification so local CLI/TUI sessions stop entering pairing-required loops for pairing/approval-scoped commands. (#22062, #22193, #21191) Thanks @Botaccess, @jhartshorn, and @ctbritt.
 - Gateway/Pairing: preserve existing approved token scopes when processing repair pairings that omit `scopes`, preventing empty-scope token regressions on reconnecting clients. (#21906) Thanks @paki81.

src/agents/models-config.fills-missing-provider-apikey-from-env-var.e2e.test.ts

@@ -2,6 +2,7 @@ import fs from "node:fs/promises";
 import path from "node:path";
 import { describe, expect, it } from "vitest";
 import type { OpenClawConfig } from "../config/config.js";
+import { validateConfigObject } from "../config/validation.js";
 import { resolveOpenClawAgentDir } from "./agent-paths.js";
 import {
   CUSTOM_PROXY_MODELS_CONFIG,
@@ -13,6 +14,37 @@ import { ensureOpenClawModelsJson } from "./models-config.js";
 installModelsConfigTestHooks();
 
 describe("models-config", () => {
+  it("keeps anthropic api defaults when model entries omit api", async () => {
+    await withTempHome(async () => {
+      const validated = validateConfigObject({
+        models: {
+          providers: {
+            anthropic: {
+              baseUrl: "https://relay.example.com/api",
+              apiKey: "cr_xxxx",
+              models: [{ id: "claude-opus-4-6", name: "Claude Opus 4.6" }],
+            },
+          },
+        },
+      });
+      expect(validated.ok).toBe(true);
+      if (!validated.ok) {
+        throw new Error("expected config to validate");
+      }
+
+      await ensureOpenClawModelsJson(validated.config);
+
+      const modelPath = path.join(resolveOpenClawAgentDir(), "models.json");
+      const raw = await fs.readFile(modelPath, "utf8");
+      const parsed = JSON.parse(raw) as {
+        providers: Record<string, { api?: string; models?: Array<{ id: string; api?: string }> }>;
+      };
+
+      expect(parsed.providers.anthropic?.api).toBe("anthropic-messages");
+      expect(parsed.providers.anthropic?.models?.[0]?.api).toBe("anthropic-messages");
+    });
+  });
+
   it("fills missing provider.apiKey from env var name when models exist", async () => {
     await withTempHome(async () => {
       const prevKey = process.env.MINIMAX_API_KEY;

src/config/defaults.ts

@@ -1,5 +1,5 @@
 import { DEFAULT_CONTEXT_TOKENS } from "../agents/defaults.js";
-import { parseModelRef } from "../agents/model-selection.js";
+import { normalizeProviderId, parseModelRef } from "../agents/model-selection.js";
 import { DEFAULT_AGENT_MAX_CONCURRENT, DEFAULT_SUBAGENT_MAX_CONCURRENT } from "./agent-limits.js";
 import { resolveTalkApiKey } from "./talk.js";
 import type { OpenClawConfig } from "./types.js";
@@ -37,6 +37,16 @@ const DEFAULT_MODEL_MAX_TOKENS = 8192;
 type ModelDefinitionLike = Partial<ModelDefinitionConfig> &
   Pick<ModelDefinitionConfig, "id" | "name">;
 
+function resolveDefaultProviderApi(
+  providerId: string,
+  providerApi: ModelDefinitionConfig["api"] | undefined,
+): ModelDefinitionConfig["api"] | undefined {
+  if (providerApi) {
+    return providerApi;
+  }
+  return normalizeProviderId(providerId) === "anthropic" ? "anthropic-messages" : undefined;
+}
+
 function isPositiveNumber(value: unknown): value is number {
   return typeof value === "number" && Number.isFinite(value) && value > 0;
 }
@@ -181,6 +191,12 @@ export function applyModelDefaults(cfg: OpenClawConfig): OpenClawConfig {
       if (!Array.isArray(models) || models.length === 0) {
         continue;
       }
+      const providerApi = resolveDefaultProviderApi(providerId, provider.api);
+      let nextProvider = provider;
+      if (providerApi && provider.api !== providerApi) {
+        mutated = true;
+        nextProvider = { ...nextProvider, api: providerApi };
+      }
       let providerMutated = false;
       const nextModels = models.map((model) => {
         const raw = model as ModelDefinitionLike;
@@ -220,6 +236,10 @@ export function applyModelDefaults(cfg: OpenClawConfig): OpenClawConfig {
         if (raw.maxTokens !== maxTokens) {
           modelMutated = true;
         }
+        const api = raw.api ?? providerApi;
+        if (raw.api !== api) {
+          modelMutated = true;
+        }
 
         if (!modelMutated) {
           return model;
@@ -232,13 +252,17 @@ export function applyModelDefaults(cfg: OpenClawConfig): OpenClawConfig {
           cost,
           contextWindow,
           maxTokens,
+          api,
         } as ModelDefinitionConfig;
       });
 
       if (!providerMutated) {
+        if (nextProvider !== provider) {
+          nextProviders[providerId] = nextProvider;
+        }
         continue;
       }
-      nextProviders[providerId] = { ...provider, models: nextModels };
+      nextProviders[providerId] = { ...nextProvider, models: nextModels };
       mutated = true;
     }
 

src/config/model-alias-defaults.test.ts

@@ -104,4 +104,64 @@ describe("applyModelDefaults", () => {
     expect(model?.contextWindow).toBe(32768);
     expect(model?.maxTokens).toBe(32768);
   });
+
+  it("defaults anthropic provider and model api to anthropic-messages", () => {
+    const cfg = {
+      models: {
+        providers: {
+          anthropic: {
+            baseUrl: "https://relay.example.com/api",
+            apiKey: "cr_xxxx",
+            models: [
+              {
+                id: "claude-opus-4-6",
+                name: "Claude Opus 4.6",
+                reasoning: false,
+                input: ["text"],
+                cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+                contextWindow: 200_000,
+                maxTokens: 8192,
+              },
+            ],
+          },
+        },
+      },
+    } satisfies OpenClawConfig;
+
+    const next = applyModelDefaults(cfg);
+    const provider = next.models?.providers?.anthropic;
+    const model = provider?.models?.[0];
+
+    expect(provider?.api).toBe("anthropic-messages");
+    expect(model?.api).toBe("anthropic-messages");
+  });
+
+  it("propagates provider api to models when model api is missing", () => {
+    const cfg = {
+      models: {
+        providers: {
+          myproxy: {
+            baseUrl: "https://proxy.example/v1",
+            apiKey: "sk-test",
+            api: "openai-completions",
+            models: [
+              {
+                id: "gpt-5.2",
+                name: "GPT-5.2",
+                reasoning: false,
+                input: ["text"],
+                cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
+                contextWindow: 200_000,
+                maxTokens: 8192,
+              },
+            ],
+          },
+        },
+      },
+    } satisfies OpenClawConfig;
+
+    const next = applyModelDefaults(cfg);
+    const model = next.models?.providers?.myproxy?.models?.[0];
+    expect(model?.api).toBe("openai-completions");
+  });
 });