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

# Proxy vs Unified API vs MCP

> Three ways to call a connected account. How to choose between them, and why you don’t have to choose only one.

Once a user has connected an account, you can call it three ways. All three share the same connection IDs, API keys, rate limits and logs, so this is a per-request decision, not a platform choice.

```mermaid theme={null}
flowchart TD
    Q1{"Is the caller<br/>an AI agent?"}
    Q1 -->|Yes| Q4{"Does the provider run<br/>its own MCP server?"}
    Q4 -->|Yes| MCP["MCP<br/>mcp.bundleup.io"]
    Q4 -->|No| PROXY
    Q1 -->|No| Q2{"Do you need the same data<br/>from several providers<br/>in one shape?"}
    Q2 -->|Yes| Q3{"Does the Unified API<br/>cover what you need?"}
    Q3 -->|Yes| UNIFY["Unified API<br/>unify.bundleup.io"]
    Q3 -->|No| PROXY["Proxy<br/>proxy.bundleup.io"]
    Q2 -->|No| PROXY
```

Start at the top. If an AI agent is calling and the provider runs an MCP server, use MCP. Otherwise, if you need one data shape across several providers and the Unified API covers it, use the Unified API. In every other case, use the Proxy.

## At a glance

| | Proxy | Unified API | MCP |
| - | - | - | - |
| **You call** | The provider’s own endpoints | BundleUp’s normalized endpoints | The provider’s MCP server |
| **Request and response shape** | The provider’s, unchanged | The same for every provider in a category | MCP JSON-RPC, defined by the provider |
| **Coverage** | Everything the provider’s API offers | Common read operations per category, plus sending chat messages | Whatever tools the provider exposes |
| **Best for** | Provider-specific features, writes, full control | Features that work across many providers | AI agents acting on a user’s behalf |
| **Retries** | Yes, for idempotent requests | Yes, for idempotent requests | No. Your MCP client decides |
| **Rate limit** | 100 requests / 60s per connection | Same | Same |
| **Base URL** | `https://proxy.bundleup.io` | `https://unify.bundleup.io` | `https://mcp.bundleup.io` |

## Use the Proxy when

* You integrate deeply with **one provider** and want its full API.
* You need a **write** operation or a provider-specific feature the Unified API doesn’t model.
* You already have code that calls the provider directly. Point it at `proxy.bundleup.io`, add two headers, and delete your token handling.

The Proxy is a transparent pass-through: the provider’s paths, query parameters, bodies and responses, unchanged. See [Proxy overview](/docs/guides/proxy/overview).

## Use the Unified API when

* You want a feature to work across **every provider in a category** (for example, “import issues from whichever tracker the customer uses”) without writing per-provider code.
* The data you need is covered by the [categories](/docs/guides/unified/overview): account, chat, git, tasks, helpdesk, CRM, drive and calendar.

You can always fetch the provider’s original payload alongside the normalized one with `include_raw=true`. See [Unified API overview](/docs/guides/unified/overview).

## Use MCP when

* An **AI agent** needs to act in a user’s account, and the provider runs its own MCP server.
* You want the provider’s tools (names, descriptions, schemas) as-is, kept up to date by the provider.

BundleUp keeps the token away from the agent and picks the right account by connection ID. See [MCP overview](/docs/guides/mcp/overview).

## Mixing them

Because all three use the same connection, mixing them is normal:

* A sync job reads tasks through the **Unified API**, then posts a provider-specific comment through the **Proxy**.
* An agent uses **MCP** for most tools, while your backend uses the **Proxy** for a scheduled export from the same account.

Every request, whichever surface it uses, shows up in the same [request log](/docs/guides/operations/logs) and counts toward the same rate limit for that connection.


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