diff --git a/litellm/proxy/public_endpoints/public_endpoints.py b/litellm/proxy/public_endpoints/public_endpoints.py
index 137f91f9b6e..8903b22c120 100644
--- a/litellm/proxy/public_endpoints/public_endpoints.py
+++ b/litellm/proxy/public_endpoints/public_endpoints.py
@@ -3,11 +3,12 @@ import json
 import os
 import re
 from collections.abc import Awaitable, Callable, Mapping, Sequence
+from functools import cache
 from importlib.resources import files
 from typing import TYPE_CHECKING, Final, Protocol
 
 from fastapi import APIRouter, HTTPException, Request
-from pydantic import TypeAdapter
+from pydantic import ConfigDict, TypeAdapter
 from typing_extensions import ReadOnly, TypedDict
 
 import litellm
@@ -31,6 +32,7 @@ from litellm.types.proxy.management_endpoints.model_management_endpoints import
 )
 from litellm.types.proxy.public_endpoints.public_endpoints import (
     AgentCreateInfo,
+    AgentCredentialField,
     AutoRouterPresetRecord,
     ComplexityScorerDefaults,
     ProviderCreateInfo,
@@ -210,6 +212,54 @@ def _load_endpoints() -> list[_EndpointEntry]:
     return _build_endpoints(raw)
 
 
+class _BundledAgentCreateInfo(AgentCreateInfo):
+    model_config = ConfigDict(frozen=True)
+
+    inherit_credentials_from_provider: str | None = None
+
+
+_BUNDLED_AGENTS_ADAPTER: Final = TypeAdapter(list[_BundledAgentCreateInfo])
+
+
+def _read_bundled_file(filename: str) -> bytes:
+    return files("litellm.proxy.public_endpoints").joinpath(filename).read_bytes()
+
+
+@cache
+def _provider_create_fields() -> tuple[ProviderCreateInfo, ...]:
+    return tuple(_PROVIDER_CREATE_FIELDS_ADAPTER.validate_json(_read_bundled_file("provider_create_fields.json")))
+
+
+def _inherited_credential_fields(provider: ProviderCreateInfo) -> tuple[AgentCredentialField, ...]:
+    return tuple(
+        AgentCredentialField.model_validate({**field.model_dump(), "include_in_litellm_params": True})
+        for field in provider.credential_fields
+    )
+
+
+def _with_inherited_credentials(
+    agent: _BundledAgentCreateInfo, providers: Mapping[str, ProviderCreateInfo]
+) -> AgentCreateInfo:
+    provider_name: Final = agent.inherit_credentials_from_provider
+    provider: Final = providers.get(provider_name) if provider_name else None
+    inherited: Final = _inherited_credential_fields(provider) if provider else ()
+    return AgentCreateInfo.model_validate(
+        {
+            **agent.model_dump(exclude={"inherit_credentials_from_provider"}),
+            "credential_fields": [*agent.credential_fields, *inherited],
+        }
+    )
+
+
+@cache
+def _agent_create_fields() -> tuple[AgentCreateInfo, ...]:
+    providers: Final = {provider.provider: provider for provider in _provider_create_fields()}
+    return tuple(
+        _with_inherited_credentials(agent, providers)
+        for agent in _BUNDLED_AGENTS_ADAPTER.validate_json(_read_bundled_file("agent_create_fields.json"))
+    )
+
+
 # ---------------------------------------------------------------------------
 
 
@@ -404,22 +454,15 @@ async def get_supported_providers() -> list[str]:
     tags=["public", "providers"],
     response_model=list[ProviderCreateInfo],
 )
-async def get_provider_fields() -> list[ProviderCreateInfo]:
+async def get_provider_fields() -> tuple[ProviderCreateInfo, ...]:
     """
     Return provider metadata required by the dashboard create-model flow.
+
+    Reads from the bundled local file. Result is cached in-process for the
+    lifetime of the server process.
     """
 
-    provider_create_fields_path: Final = os.path.join(
-        os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
-        "proxy",
-        "public_endpoints",
-        "provider_create_fields.json",
-    )
-
-    with open(provider_create_fields_path, "r") as f:
-        provider_create_fields: Final = _PROVIDER_CREATE_FIELDS_ADAPTER.validate_python(json.load(f))
-
-    return provider_create_fields
+    return _provider_create_fields()
 
 
 @router.get(
@@ -601,45 +644,14 @@ async def get_supported_endpoints() -> SupportedEndpointsResponse:
     tags=["public", "[beta] Agents"],
     response_model=list[AgentCreateInfo],
 )
-async def get_agent_fields() -> list[AgentCreateInfo]:
+async def get_agent_fields() -> tuple[AgentCreateInfo, ...]:
     """
     Return agent type metadata required by the dashboard create-agent flow.
 
     If an agent has `inherit_credentials_from_provider`, the provider's credential
     fields are automatically appended to the agent's credential_fields.
+
+    Reads from the bundled local files. Result is cached in-process for the
+    lifetime of the server process.
     """
-    base_path: Final = os.path.join(
-        os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
-        "proxy",
-        "public_endpoints",
-    )
-
-    agent_create_fields_path: Final = os.path.join(base_path, "agent_create_fields.json")
-    provider_create_fields_path: Final = os.path.join(base_path, "provider_create_fields.json")
-
-    with open(agent_create_fields_path, "r") as f:
-        agent_create_fields: Final = json.load(f)
-
-    with open(provider_create_fields_path, "r") as f:
-        provider_create_fields: Final = json.load(f)
-
-    # Build a lookup map for providers by name
-    provider_map: Final = {p["provider"]: p for p in provider_create_fields}
-
-    # Merge inherited credential fields
-    for agent in agent_create_fields:
-        inherit_from = agent.get("inherit_credentials_from_provider")
-        if inherit_from and inherit_from in provider_map:
-            provider = provider_map[inherit_from]
-            # Copy provider fields and mark them for inclusion in litellm_params
-            inherited_fields = []
-            for field in provider.get("credential_fields", []):
-                field_copy = field.copy()
-                field_copy["include_in_litellm_params"] = True
-                inherited_fields.append(field_copy)
-            # Append provider credential fields after agent's own fields
-            agent["credential_fields"] = agent.get("credential_fields", []) + inherited_fields
-        # Remove the inherit field from response (not needed by frontend)
-        agent.pop("inherit_credentials_from_provider", None)
-
-    return agent_create_fields
+    return _agent_create_fields()
diff --git a/tests/unit/proxy/public_endpoints/test_public_endpoints.py b/tests/unit/proxy/public_endpoints/test_public_endpoints.py
index 9c26804a1db..b03dbede869 100644
--- a/tests/unit/proxy/public_endpoints/test_public_endpoints.py
+++ b/tests/unit/proxy/public_endpoints/test_public_endpoints.py
@@ -2,6 +2,8 @@ import asyncio
 import json
 import re
 from datetime import datetime, timezone
+from importlib.resources import files
+from itertools import chain
 from types import SimpleNamespace
 from typing import Final
 from unittest.mock import AsyncMock, MagicMock, patch
@@ -18,7 +20,7 @@ from litellm.router_strategy.complexity_router.fuse_presets import get_fuse_pres
 from litellm.types.proxy.management_endpoints.model_management_endpoints import (
     ModelGroupInfoProxy,
 )
-from litellm.types.proxy.public_endpoints.public_endpoints import ProviderCreateInfo
+from litellm.types.proxy.public_endpoints.public_endpoints import ProviderCreateInfo, ProviderCredentialField
 from litellm.types.utils import LlmProviders
 
 
@@ -1563,6 +1565,59 @@ async def test_fetch_remote_autorouter_presets_parses_and_rejects_empty(monkeypa
         await _fetch_remote_autorouter_presets("https://example.test/presets.json")
 
 
+# ---------------------------------------------------------------------------
+# /public/agents/fields inherited provider credentials
+# ---------------------------------------------------------------------------
+
+
+def test_get_agent_fields_merge_does_not_compound_across_requests():
+    """The inherited-credentials merge runs once, so credential_fields cannot grow per request.
+
+    Caching the raw file contents instead of the merged result would let the merge
+    append inherited fields again on every request.
+    """
+    client = _make_client()
+
+    def counts():
+        return {
+            agent["agent_type"]: len(agent.get("credential_fields") or [])
+            for agent in client.get("/public/agents/fields").json()
+        }
+
+    first = counts()
+    assert first, "expected at least one agent type"
+    assert first == counts() == counts()
+
+
+def test_get_agent_fields_appends_inherited_provider_credential_fields():
+    client: Final = _make_client()
+    providers: Final = {p["provider"]: p for p in client.get("/public/providers/fields").json()}
+    agents: Final = client.get("/public/agents/fields").json()
+    bundled: Final = json.loads(
+        files("litellm.proxy.public_endpoints").joinpath("agent_create_fields.json").read_text(encoding="utf-8")
+    )
+    own_counts: Final = {agent["agent_type"]: len(agent["credential_fields"]) for agent in bundled}
+    expected_inherited: Final = {
+        agent["agent_type"]: providers.get(agent.get("inherit_credentials_from_provider"), {}).get(
+            "credential_fields", []
+        )
+        for agent in bundled
+    }
+    inherited: Final = {
+        agent["agent_type"]: agent["credential_fields"][own_counts[agent["agent_type"]] :] for agent in agents
+    }
+
+    assert any(expected_inherited.values()), "expected at least one agent to inherit provider credential fields"
+    assert all("inherit_credentials_from_provider" not in agent for agent in agents)
+    assert {
+        agent_type: [
+            {key: field[key] for key in field if key in ProviderCredentialField.model_fields} for field in fields
+        ]
+        for agent_type, fields in inherited.items()
+    } == expected_inherited
+    assert all(field["include_in_litellm_params"] is True for field in chain.from_iterable(inherited.values()))
+
+
 @pytest.mark.parametrize("preference", ["auto_install", None])
 def test_public_skill_hub_echoes_registered_installation_preference(preference):
     from litellm.proxy._types import LitellmUserRoles, UserAPIKeyAuth
diff --git a/ui/litellm-dashboard/src/lib/http/schema.d.ts b/ui/litellm-dashboard/src/lib/http/schema.d.ts
index 94100646a7d..c3dde3b4d47 100644
--- a/ui/litellm-dashboard/src/lib/http/schema.d.ts
+++ b/ui/litellm-dashboard/src/lib/http/schema.d.ts
@@ -13438,6 +13438,9 @@ export interface paths {
          *
          *     If an agent has `inherit_credentials_from_provider`, the provider's credential
          *     fields are automatically appended to the agent's credential_fields.
+         *
+         *     Reads from the bundled local files. Result is cached in-process for the
+         *     lifetime of the server process.
          */
         get: operations["get_agent_fields_public_agents_fields_get"];
         put?: never;
@@ -13659,6 +13662,9 @@ export interface paths {
         /**
          * Get Provider Fields
          * @description Return provider metadata required by the dashboard create-model flow.
+         *
+         *     Reads from the bundled local file. Result is cached in-process for the
+         *     lifetime of the server process.
          */
         get: operations["get_provider_fields_public_providers_fields_get"];
         put?: never;