PaperClipAI/docs/adapters/overview.md

---
title: Adapters Overview
summary: What adapters are and how they connect agents to Paperclip
---

Adapters are the bridge between Paperclip's orchestration layer and agent runtimes. Each adapter knows how to invoke a specific type of AI agent and capture its results.

## How Adapters Work

When a heartbeat fires, Paperclip:

1. Looks up the agent's `adapterType` and `adapterConfig`
2. Calls the adapter's `execute()` function with the execution context
3. The adapter spawns or calls the agent runtime
4. The adapter captures stdout, parses usage/cost data, and returns a structured result

## Built-in Adapters

| Adapter | Type Key | Description |
|---------|----------|-------------|
| [Claude Code](/adapters/claude-local) | `claude_local` | Runs Claude Code CLI locally, with a native ACP engine when available |
| [Codex](/adapters/codex-local) | `codex_local` | Runs OpenAI Codex CLI locally, with a native ACP engine when available |
| [Gemini CLI](/adapters/gemini-local) | `gemini_local` | Runs Gemini CLI locally (experimental — adapter package exists, not yet in stable type enum) |
| OpenCode | `opencode_local` | Runs OpenCode CLI locally (multi-provider `provider/model`) |
| Cursor | `cursor` | Runs Cursor in background mode |
| Pi | `pi_local` | Runs an embedded Pi agent locally |
| Hermes | `hermes_local` | Runs the local Hermes CLI through `@paperclipai/hermes-paperclip-adapter` |
| Hermes Gateway | `hermes_gateway` | Calls an already-running Hermes API server through `@paperclipai/hermes-paperclip-adapter/gateway` |
| OpenClaw Gateway | `openclaw_gateway` | Connects to an OpenClaw gateway endpoint |
| [Process](/adapters/process) | `process` | Executes arbitrary shell commands |
| [HTTP](/adapters/http) | `http` | Sends webhooks to external agents |

## Credential ownership for sandbox targets

Local CLI adapters can run on the Paperclip host, SSH targets, or managed
sandbox targets. The adapter decides which credential home is authoritative
before the CLI starts:

| Adapter | Credential topology | Which credential file wins on managed sandbox targets |
|---------|---------------------|-------------------------------------------------------|
| [`codex_local`](/adapters/codex-local) | Host-owns-auth for Paperclip-managed `CODEX_HOME` | A host-owned `auth.json` is symlinked into the managed `CODEX_HOME` and uploaded to the sandbox. If a per-agent `OPENAI_API_KEY` is configured, Paperclip writes an API-key `auth.json` instead and that file wins. A login baked into the sandbox image is shadowed because Codex runs with Paperclip's uploaded `CODEX_HOME`. |
| [`claude_local`](/adapters/claude-local) | Snapshot-owns-auth for managed remote Claude config | Paperclip uploads only sanitized settings and skill/runtime assets. When the remote managed config has no Claude credential files, it copies `.credentials.json` or `credentials.json` from the sandbox image's own `$HOME/.claude`, so the image's login wins. |

Worked examples:

- **Codex sandbox with host ChatGPT login:** the host `~/.codex/auth.json`
  is symlinked into the managed home, then uploaded as the sandbox
  `CODEX_HOME`. Codex reads that uploaded file and does not use any
  `auth.json` already present inside the sandbox image.
- **Claude sandbox with image login:** Paperclip materializes a remote
  `CLAUDE_CONFIG_DIR`, then fills missing `.credentials.json` /
  `credentials.json` from the sandbox image's own `$HOME/.claude`. The
  snapshot's Claude login is the credential source for the run.

### Hermes local vs gateway

Use `hermes_local` when Paperclip should start the local `hermes` CLI on the
same host for each heartbeat. Use `hermes_gateway` when Hermes is already
running as an HTTP/SSE API server and Paperclip should call that server instead
of spawning a process. Both type keys are stable built-ins.

The unified Hermes package owns both built-in adapters. The older
`@paperclipai/adapter-hermes-gateway` package remains only as a deprecated
compatibility shim that re-exports the gateway entrypoints for one release.
New plugin overrides should target `@paperclipai/hermes-paperclip-adapter` and
set the desired type key (`hermes_local` or `hermes_gateway`).

### External (plugin) adapters

These adapters ship as standalone npm packages and are installed via the plugin system:

| Adapter | Package | Type Key | Description |
|---------|---------|----------|-------------|
| Droid | `@henkey/droid-paperclip-adapter` | `droid_local` | Runs Factory Droid locally |

## External Adapters

You can build and distribute adapters as standalone packages — no changes to Paperclip's source code required. External adapters are loaded at startup via the plugin system.

```sh
# Install from npm via API
curl -X POST http://localhost:3102/api/adapters \
  -d '{"packageName": "my-paperclip-adapter"}'

# Or link from a local directory
curl -X POST http://localhost:3102/api/adapters \
  -d '{"localPath": "/home/user/my-adapter"}'
```

See [External Adapters](/adapters/external-adapters) for the full guide.

## Adapter Architecture

Each adapter is a package with modules consumed by three registries:

```
my-adapter/
  src/
    index.ts            # Shared metadata (type, label, models)
    server/
      execute.ts        # Core execution logic
      parse.ts          # Output parsing
      test.ts           # Environment diagnostics
    ui-parser.ts        # Self-contained UI transcript parser (for external adapters)
    cli/
      format-event.ts   # Terminal output for `paperclipai run --watch`
```

| Registry | What it does | Source |
|----------|-------------|--------|
| **Server** | Executes agents, captures results | `createServerAdapter()` from package root |
| **UI** | Renders run transcripts, provides config forms | `ui-parser.js` (dynamic) or static import (built-in) |
| **CLI** | Formats terminal output for live watching | Static import |

## Choosing an Adapter

- **Need a coding agent?** Use `claude_local`, `codex_local`, `opencode_local`, `hermes_local`, or install `droid_local` as an external plugin
- **Need the richest live run feedback?** Use `claude_local`, `codex_local`, or `gemini_local` with `adapterConfig.engine` set to `acp` when the execution environment satisfies the ACP prerequisites — see [Feedback granularity](#feedback-granularity)
- **Need Hermes on another host or already running as a service?** Use `hermes_gateway`
- **Need to run a script or command?** Use `process`
- **Need to call a custom external service?** Use `http`
- **Need something custom?** [Create your own adapter](/adapters/creating-an-adapter) or [build an external adapter plugin](/adapters/external-adapters)

## Feedback Granularity

Adapter choice determines how much structured, live detail a run's transcript can show while the agent is still working. Every adapter's stdout is streamed to the run log and rendered live in the UI — including runs on sandbox execution targets, whose logs are tailed and delivered incrementally — but the *granularity* of what you see depends on the event stream the adapter emits.

Rough tiers, richest first:

1. **Native ACP engine (`claude_local`, `codex_local`, or `gemini_local` with `engine: "acp"`) — full structured event stream.** ACP emits a JSONL event per meaningful runtime moment: `acpx.session` (agent, mode, session identity), `acpx.status` (progress text plus context-window usage), `acpx.text_delta` (assistant/thinking token deltas), `acpx.tool_call` (tool title, call id, and status updates as the call progresses), `acpx.result` (stop reason summary), and `acpx.error` (code, message, retryability). The transcript renders these as live-updating message, thinking, tool, and status blocks, and repeated `acpx.tool_call` status updates fold into a single tool card instead of stacking duplicates.
2. **CLI wrappers (`claude_local`, `codex_local`, `cursor`, `opencode_local`, …).** These parse each CLI's own streaming JSON output. You get assistant text, tool calls/results, and a final usage/cost summary, but granularity is limited to what the CLI prints — some emit tool progress, others only call/finish pairs.
3. **Generic adapters (`process`, `http`).** Plain stdout/stderr lines with no structured transcript — you see raw output only.

**Recommendation:** use the native ACP engine on `claude_local`, `codex_local`, or `gemini_local` when the selected execution environment supports it. Rich ACP status events (including context usage) and incremental tool-call updates give the closest thing to watching the agent work locally.

## UI Parser Contract

External adapters can ship a self-contained UI parser that tells the Paperclip web UI how to render their stdout. Without it, the UI uses a generic shell parser. See the [UI Parser Contract](/adapters/adapter-ui-parser) for details.