# MCP Core Tools Contract

Date: 2026-07-09

## Route statement

项目核心不是继续做 UIA selector/report，而是通过 MCP 暴露 iSphere 的联系人、群组、消息、文件能力。

This contract defines the business-facing MCP tool surface. The existing `win_helper_*` tools remain low-level auxiliary tools for controlled read-only observation and fallback implementation work. They are not the product API.

## Hard boundaries

- No automatic login.
- No permission bypass.
- No process injection, hook, target-process memory read, credential extraction, or endpoint-security bypass.
- Search contacts, search groups, receive messages, and receive files should be implemented read-only first.
- Real message sending and file sending require `approval_id`.
- Without `approval_id`, write-capable tools must stay in `dry_run=true` behavior and must not send.
- Every real write must produce an audit record with target, content/file hash, approver, timestamp, source connector, and result.
- UIA selectors are allowed only as fallback access mechanics after higher-priority sources are exhausted or unavailable.

## Common error codes

| Code | Meaning |
| --- | --- |
| `INVALID_ARGUMENT` | Required parameter missing or invalid. |
| `SOURCE_UNAVAILABLE` | Selected bridge/API/database/UIA source is unavailable. |
| `NOT_LOGGED_IN` | A required manually logged-in client session is not present. |
| `PERMISSION_DENIED` | Current operator/account is not authorized for the requested object. |
| `APPROVAL_REQUIRED` | A real write was requested without valid approval. |
| `DRY_RUN_ONLY` | Tool is currently limited to dry-run behavior. |
| `TARGET_NOT_FOUND` | Contact, group, conversation, message, or file was not found. |
| `AMBIGUOUS_TARGET` | Multiple possible targets match and the request must be narrowed. |
| `TIMEOUT` | The connector did not complete before timeout. |
| `CONNECTOR_FAILED` | Underlying source or helper returned a structured failure. |
| `INTERNAL_ERROR` | Unexpected implementation error. |

## Common audit fields

Every tool response should include an `audit` object:

```json
{
  "tool": "isphere_search_contacts",
  "request_id": "uuid",
  "source": "bridge|local_readonly|uia|network|mock",
  "operator_id": "optional operator identity",
  "approval_id": null,
  "dry_run": false,
  "target_ref": "optional stable target reference",
  "content_sha256": null,
  "file_sha256": null,
  "started_at": "ISO-8601",
  "finished_at": "ISO-8601",
  "result": "ok|error"
}
```

## Tool: `isphere_search_contacts`

| Field | Value |
| --- | --- |
| Business purpose | Search authorized iSphere contacts so a digital employee can resolve a person before reading or drafting work. |
| Read-only | Yes. |
| Requires `approval_id` | No. |
| Supports `dry_run` | Not required; optional `dry_run` may return the planned query only. |
| Current priority | Stage C read-only loop, first priority. |

Input parameters:

```json
{
  "query": "string, required",
  "limit": "integer, optional, default 20, max 100",
  "cursor": "string, optional",
  "source_preference": "bridge|local_readonly|uia|network|auto, optional, default auto",
  "include_inactive": "boolean, optional, default false"
}
```

Output JSON:

```json
{
  "ok": true,
  "contacts": [
    {
      "contact_id": "string",
      "display_name": "string",
      "account": "string|null",
      "department": "string|null",
      "title": "string|null",
      "source": "bridge|local_readonly|uia|network|mock",
      "confidence": 0.98,
      "raw_ref": "redacted source reference"
    }
  ],
  "next_cursor": null,
  "audit": {}
}
```

Errors: `INVALID_ARGUMENT`, `SOURCE_UNAVAILABLE`, `NOT_LOGGED_IN`, `PERMISSION_DENIED`, `TIMEOUT`, `CONNECTOR_FAILED`, `INTERNAL_ERROR`.

## Tool: `isphere_search_groups`

| Field | Value |
| --- | --- |
| Business purpose | Search authorized iSphere groups so a digital employee can resolve a group conversation before reading or drafting work. |
| Read-only | Yes. |
| Requires `approval_id` | No. |
| Supports `dry_run` | Not required; optional `dry_run` may return the planned query only. |
| Current priority | Stage C read-only loop, first priority. |

Input parameters:

```json
{
  "query": "string, required",
  "limit": "integer, optional, default 20, max 100",
  "cursor": "string, optional",
  "source_preference": "bridge|local_readonly|uia|network|auto, optional, default auto",
  "include_archived": "boolean, optional, default false"
}
```

Output JSON:

```json
{
  "ok": true,
  "groups": [
    {
      "group_id": "string",
      "display_name": "string",
      "member_count": "integer|null",
      "owner_ref": "string|null",
      "source": "bridge|local_readonly|uia|network|mock",
      "confidence": 0.96,
      "raw_ref": "redacted source reference"
    }
  ],
  "next_cursor": null,
  "audit": {}
}
```

Errors: `INVALID_ARGUMENT`, `SOURCE_UNAVAILABLE`, `NOT_LOGGED_IN`, `PERMISSION_DENIED`, `TIMEOUT`, `CONNECTOR_FAILED`, `INTERNAL_ERROR`.

## Tool: `isphere_receive_messages`

| Field | Value |
| --- | --- |
| Business purpose | Read authorized recent messages and normalize them for digital employee reasoning and drafting. |
| Read-only | Yes. |
| Requires `approval_id` | No. |
| Supports `dry_run` | Optional; if true, returns source/query plan without message bodies. |
| Current priority | Stage C read-only loop, first priority after contact/group source discovery. |

Input parameters:

```json
{
  "conversation_id": "string, optional when query is supplied",
  "conversation_type": "direct|group|system|unknown, optional",
  "query": "string, optional target name or keyword",
  "since": "ISO-8601 timestamp, optional",
  "limit": "integer, optional, default 50, max 200",
  "cursor": "string, optional",
  "include_attachment_metadata": "boolean, optional, default true",
  "source_preference": "bridge|local_readonly|uia|network|auto, optional, default auto",
  "dry_run": "boolean, optional, default false"
}
```

Output JSON:

```json
{
  "ok": true,
  "conversation": {
    "conversation_id": "string",
    "conversation_type": "direct|group|system",
    "display_name": "string"
  },
  "messages": [
    {
      "message_id": "string",
      "sender_id": "string|null",
      "sender_name": "string|null",
      "content_type": "text|image|file|rich|notify|unknown",
      "content_text": "authorized text or redacted summary",
      "attachments": [
        {
          "file_id": "string",
          "file_name": "string",
          "size_bytes": "integer|null",
          "download_ref": "string|null"
        }
      ],
      "created_at": "ISO-8601|null",
      "received_at": "ISO-8601|null",
      "source": "bridge|local_readonly|uia|network|mock",
      "raw_ref": "redacted source reference"
    }
  ],
  "next_cursor": null,
  "audit": {}
}
```

Errors: `INVALID_ARGUMENT`, `SOURCE_UNAVAILABLE`, `NOT_LOGGED_IN`, `PERMISSION_DENIED`, `TARGET_NOT_FOUND`, `TIMEOUT`, `CONNECTOR_FAILED`, `INTERNAL_ERROR`.

## Tool: `isphere_receive_files`

| Field | Value |
| --- | --- |
| Business purpose | List and receive/download authorized files from messages without mutating the iSphere client state. |
| Read-only | Yes for source/client state. It may write downloaded files only to an operator-approved local output directory. |
| Requires `approval_id` | No for read-only listing or authorized download. Approval can be added later for sensitive destinations. |
| Supports `dry_run` | Yes. `dry_run=true` lists planned files and destination paths without downloading. |
| Current priority | Stage C read-only loop after messages expose file metadata. |

Implementation note: if the implementation becomes clearer with two internal operations, split into `list_files` and `download_file` behind this business contract. Do not expand the roadmap beyond receive/download.

Input parameters:

```json
{
  "conversation_id": "string, optional",
  "message_id": "string, optional",
  "file_id": "string, optional for download, omitted for list",
  "mode": "list|download, optional, default list",
  "output_dir": "string, optional, required for download",
  "limit": "integer, optional, default 50, max 200",
  "cursor": "string, optional",
  "source_preference": "bridge|local_readonly|uia|network|auto, optional, default auto",
  "dry_run": "boolean, optional, default true for download"
}
```

Output JSON:

```json
{
  "ok": true,
  "mode": "list|download",
  "files": [
    {
      "file_id": "string",
      "message_id": "string|null",
      "conversation_id": "string|null",
      "file_name": "string",
      "size_bytes": "integer|null",
      "mime_type": "string|null",
      "created_at": "ISO-8601|null",
      "download_ref": "string|null",
      "saved_path": "string|null",
      "sha256": "string|null",
      "source": "bridge|local_readonly|uia|network|mock"
    }
  ],
  "next_cursor": null,
  "audit": {}
}
```

Errors: `INVALID_ARGUMENT`, `SOURCE_UNAVAILABLE`, `NOT_LOGGED_IN`, `PERMISSION_DENIED`, `TARGET_NOT_FOUND`, `DRY_RUN_ONLY`, `TIMEOUT`, `CONNECTOR_FAILED`, `INTERNAL_ERROR`.

## Tool: `isphere_send_message`

| Field | Value |
| --- | --- |
| Business purpose | Send an approved text message to a resolved contact or group. |
| Read-only | No. |
| Requires `approval_id` | Yes for any real send. |
| Supports `dry_run` | Yes, required. Default must be `true` until production approval flow is accepted. |
| Current priority | Stage D approval-after-read-only loop. |

Input parameters:

```json
{
  "target_type": "contact|group|conversation, required",
  "target_id": "string, required",
  "content_text": "string, required",
  "approval_id": "string, required when dry_run=false",
  "dry_run": "boolean, optional, default true",
  "idempotency_key": "string, optional but recommended",
  "source_preference": "bridge|uia|network|auto, optional, default auto"
}
```

Output JSON:

```json
{
  "ok": true,
  "dry_run": true,
  "send_status": "planned|sent|rejected",
  "target": {
    "target_type": "contact|group|conversation",
    "target_id": "string",
    "display_name": "string|null"
  },
  "message_ref": null,
  "content_sha256": "sha256 hex",
  "audit": {}
}
```

Errors: `INVALID_ARGUMENT`, `APPROVAL_REQUIRED`, `PERMISSION_DENIED`, `NOT_LOGGED_IN`, `TARGET_NOT_FOUND`, `AMBIGUOUS_TARGET`, `DRY_RUN_ONLY`, `TIMEOUT`, `CONNECTOR_FAILED`, `INTERNAL_ERROR`.

## Tool: `isphere_send_file`

| Field | Value |
| --- | --- |
| Business purpose | Send an approved local file to a resolved contact or group. |
| Read-only | No. |
| Requires `approval_id` | Yes for any real send. |
| Supports `dry_run` | Yes, required. Default must be `true` until production approval flow is accepted. |
| Current priority | Stage D after `isphere_send_message`. |

Input parameters:

```json
{
  "target_type": "contact|group|conversation, required",
  "target_id": "string, required",
  "file_path": "string, required; must be under an approved outbound directory",
  "caption": "string, optional",
  "approval_id": "string, required when dry_run=false",
  "dry_run": "boolean, optional, default true",
  "idempotency_key": "string, optional but recommended",
  "source_preference": "bridge|uia|network|auto, optional, default auto"
}
```

Output JSON:

```json
{
  "ok": true,
  "dry_run": true,
  "send_status": "planned|sent|rejected",
  "target": {
    "target_type": "contact|group|conversation",
    "target_id": "string",
    "display_name": "string|null"
  },
  "file_ref": null,
  "file_sha256": "sha256 hex",
  "file_size_bytes": 12345,
  "audit": {}
}
```

Errors: `INVALID_ARGUMENT`, `APPROVAL_REQUIRED`, `PERMISSION_DENIED`, `NOT_LOGGED_IN`, `TARGET_NOT_FOUND`, `AMBIGUOUS_TARGET`, `DRY_RUN_ONLY`, `TIMEOUT`, `CONNECTOR_FAILED`, `INTERNAL_ERROR`.

## Stage priority summary

| Priority | Tool | Stage |
| --- | --- | --- |
| 1 | `isphere_search_contacts` | C read-only loop |
| 2 | `isphere_search_groups` | C read-only loop |
| 3 | `isphere_receive_messages` | C read-only loop |
| 4 | `isphere_receive_files` | C read-only loop |
| 5 | `isphere_send_message` | D approval-backed write |
| 6 | `isphere_send_file` | D approval-backed write |