---
title: I cannot connect to my docker deployment, what should I do?
description: "Cannot reach your Langfuse Docker deployment? Check ports, environment variables, database connectivity, and container logs in that order."
tags: [self-hosting]
---

# I cannot connect to my self-hosted Langfuse instance, what should I do?

If you encounter issues while [self-hosting](/self-hosting) Langfuse, ensure the following:

- `NEXTAUTH_URL` exactly matches the URL you're accessing Langfuse with. Pay attention to the protocol (http vs https) and the port (e.g., 3000 if you do not expose Langfuse on port 80).
- Set `HOSTNAME` to `0.0.0.0` if you cannot access Langfuse.
- SSO: Ensure that the OAuth provider is configured correctly. The return path needs to match the `NEXTAUTH_URL`, and the OAuth client needs to be configured with the correct callback URL.
- Encode special characters in `DATABASE_URL`, see this StackOverflow [answer](https://stackoverflow.com/a/68213745) for details.
- If you use the SDKs to connect with Langfuse, use `auth_check()` to verify that the connection works.
- Make sure you are at least on Postgres 12.

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---

## Agent Instructions

This page is part of the [Langfuse](https://langfuse.com) documentation, published as plain Markdown for AI agents. Every page is available as Markdown by appending `.md` to its URL, or by sending an `Accept: text/markdown` header. This page: `https://langfuse.com/faq/all/debug-docker-deployment.md`.

### Querying these docs

If the answer is not on this page, query the documentation instead of guessing:

- **Semantic search** across all Langfuse docs, returning an answer with the relevant pages and excerpts. Ask a specific, self-contained question:

  ```bash
  curl -sG "https://langfuse.com/api/search-docs" --data-urlencode "query=How do I trace a LangGraph agent?"
  ```

- **Index of every page**: <https://langfuse.com/llms.txt>, with per-section indexes [llms-docs.txt](https://langfuse.com/llms-docs.txt), [llms-integrations.txt](https://langfuse.com/llms-integrations.txt), and [llms-self-hosting.txt](https://langfuse.com/llms-self-hosting.txt).

### Before writing Langfuse code

- **Install the [Langfuse Agent Skill](https://langfuse.com/docs/api-and-data-platform/features/agent-skill).** It encodes Langfuse's own best practices for instrumentation, prompt management, and evaluation, and materially improves results.
- **Read [What does a good trace look like?](https://langfuse.com/docs/observability/best-practices.md)** before instrumenting an application.
- **Verify endpoints, parameters, and response fields** against the [API reference](https://api.reference.langfuse.com) instead of inferring them from code examples.
- **Use the [Langfuse CLI](https://langfuse.com/docs/api-and-data-platform/features/cli)** (`npx langfuse-cli api <resource> <action>`) to read or write traces, prompts, datasets, and scores from the terminal.

Found an error in these docs? Please open an issue at <https://github.com/langfuse/langfuse-docs/issues>.