LiteLLM / LiteLLM

LiteLLM Modal Endpoint Returns Persistent 404 Error Despite Working Outside Proxy

开发者通过 LiteLLM 代理调用 Modal Endpoint 时持续收到 404，但直接使用 Modal Client 和 Postman 正常，需要修复代理配置或排查兼容性问题 Includes evidence for LiteLLM troubleshooting demand.

Source-backed Last updated May 20, 2026 1 source Needs local verification

Category: LiteLLM
Error signature: 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy
Quick fix: Compare the failing environment with a known working setup, then change one configuration value at a time.
Updated: May 20, 2026
Verification status: Source-backed
Evidence: 1 public source URL

Before you change production

This page includes public source URLs in the imported troubleshooting record. Compare those references with your version and environment before applying changes.

Reproduce the smallest failing action and save non-secret logs before changing configuration.
Check versions for LiteLLM, related SDKs, package managers, CI runners, and hosting providers.
Change one setting or dependency at a time, then rerun the same failing command or request.
Avoid destructive commands, credential rotation, billing changes, or security relaxations without a rollback plan.

What this error means

404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy is a LiteLLM failure pattern reported for developers trying to 开发者通过 litellm 代理调用 modal endpoint 时持续收到 404，但直接使用 modal client 和 postman 正常，需要修复代理配置或排查兼容性问题. Based on the imported evidence, treat this as a tool-specific troubleshooting page rather than a generic API error.

Why this happens

GitHub BerriAI/litellm#25129 (2026-04-04) 明确报告此问题：Modal Endpoint 在外部可访问但经 LiteLLM 代理后返回 404。这是典型的代理路由/路径兼容性 bug，影响企业级部署。mapped to 'LiteLLM' approved category.

Common causes

GitHub BerriAI/litellm#25129 (2026-04-04) 明确报告此问题：Modal Endpoint 在外部可访问但经 LiteLLM 代理后返回 404。这是典型的代理路由/路径兼容性 bug，影响企业级部署。mapped to 'LiteLLM' approved category.

Quick fixes

Confirm the exact error signature matches 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy.
Check the LiteLLM account, local tool state, and provider configuration involved in the failing workflow.
Compare the failing environment with a known working setup, then change one configuration value at a time.

Platform/tool-specific checks

Verify the command, editor, extension, or API client that produced the error.
Compare local settings with CI, deployment, or editor-level settings when the error appears in only one environment.
Avoid deleting credentials, local model data, or project settings until the failing scope is clear.

Step-by-step troubleshooting

Capture the exact error message and the command, editor action, or request that triggered it.
Check whether the failure is account/auth, quota/rate, model/provider, local runtime, or deployment configuration.
Review the source evidence below and compare it with your environment.
Apply one change at a time and rerun the smallest failing action.
Keep the working fix documented for the team or deployment environment.

How to prevent it

Keep provider/tool configuration documented.
Record non-secret diagnostics such as tool version, provider name, model name, and command path.
Add a lightweight check before CI or production workflows depend on the tool.

Diagnostic flow for this page

Match 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy exactly before applying the quick fix.
Compare the failing environment with LiteLLM versions, account scope, provider settings, and deployment context.
Check the listed common causes in order, starting with the cause that best matches your logs.
Use the evidence status below to decide whether to confirm against public sources or official documentation.
Apply one reversible change, rerun the smallest failing action, and keep rollback notes.

FAQ

What does 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy mean in LiteLLM?

404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy indicates the workflow described by "LiteLLM Modal Endpoint Returns Persistent 404 Error Despite Working Outside Proxy" failed in a LiteLLM context. Start by confirming the exact signature and the component that emitted it.

What should I check first for 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy?

Check whether this cause matches your environment: GitHub BerriAI/litellm#25129 (2026-04-04) 明确报告此问题：Modal Endpoint 在外部可访问但经 LiteLLM 代理后返回 404。这是典型的代理路由/路径兼容性 bug，影响企业级部署。mapped to 'LiteLLM' approved category.

Is the 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy guidance source-backed?

The "LiteLLM Modal Endpoint Returns Persistent 404 Error Despite Working Outside Proxy" page is labeled source-backed. It has 1 public source URL from github.com, so use that evidence status when deciding how much additional verification you need.

When should I avoid the quick fix for 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy?

For "LiteLLM Modal Endpoint Returns Persistent 404 Error Despite Working Outside Proxy", avoid applying "Compare the failing environment with a known working setup, then change one configuration value at a time." when the error text differs, the affected version or provider is different, or the change would touch credentials, billing, DNS, production deploy settings, or irreversible data.

What should I collect before debugging 404 Error with Modal Endpoint — works via Modal Client and PostMan but fails through LiteLLM proxy?

For "LiteLLM Modal Endpoint Returns Persistent 404 Error Despite Working Outside Proxy", collect the failing LiteLLM command or request, non-secret configuration, versions, timestamps, request IDs when available, and the smallest reproduction that still triggers the signature.