> ## Documentation Index
> Fetch the complete documentation index at: https://manifest.build/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# M100: Provider API key missing

> Manifest error M100 fires when routing picks a provider that has no API key for this agent (OpenAI, Anthropic, Gemini, OpenRouter, etc). Fix: add the key in Routing.

## What you saw

```text theme={"theme":{"light":"github-light","dark":"github-dark"}}
[🦚 Manifest M100] No anthropic API key yet. Add one here: https://app.manifest.build/...
See https://manifest.build/docs/errors/M100
```

The provider name (`anthropic` in the example) varies based on which provider Manifest selected.

## Why it happened

Routing picked a provider that has no key on file for this agent. Manifest won't silently swap vendors on you, so the request stops here.

## How to fix it

1. Open the dashboard link in the error message. It goes straight to the agent's **Routing** page.
2. Either add an API key for the named provider, or remove that provider from your tier configuration so routing won't pick it again.
3. Retry the request.

## Related

* [M101: No providers configured](/errors/M101)
* [M003: Invalid key format](/errors/M003)
* [Routing](/routing)
* [API key providers](/providers/api-key-providers)
* [Subscription-based providers](/providers/subscription-based-providers)
* [All error codes](/errors)