# ref_log

> Release: 0.11.0 · Last changed: 2026-11-09 · Source: https://github.com/KeiaiLab/SwarmOps/blob/stable/docs/reference/mcp-tools/ref-log.md

One ref's moves, newest first: the op\_log entries that moved it, each with its op, old and new value, actor and time; a deleted ref lists its moves, and a name that never moved is E\_REF\_NOT\_FOUND. Pass a limit of 20 or less and page on with before, since clients limit long tool results.

```yaml
title: "ref_log"
description: "List a ref's moves."
since: "0.11.0"
mutates: false
identity_required: false
cli_command: "swarmops ref log"
envelope_op: "ref_log"
request_type: "RefLogReq"
annotations: {"destructiveHint":false,"idempotentHint":true,"openWorldHint":false,"readOnlyHint":true}
max_result_chars: null
```

## Input schema

`arguments` is a `RefLogReq`: `swarmops schema RefLogReq` prints the type. A field the type does not know is ignored.

| Field | Type | Required | Default | Description |
| --- | --- | --- | --- | --- |
| `before` | integer or null | no |  | Start below this operation: the page holds the moves of operations numbered less than it, so the last `op` of a page reads on from there. When omitted, from the newest. |
| `limit` | integer | no | `50` | The most moves to return: at least 1 (0 is `E_INVALID_ARG`). |
| `name` | string | yes |  | The ref. |

### JSON Schema

As `tools/list` gives it: each `$ref` replaced by its definition, so that it stands alone.

```json
{
  "$schema": "https://json-schema.org/draft/2020-12/schema",
  "description": "`ref_log` (CLI `ref log`): one ref's moves, newest first, a page at a time, as the journal\nrecorded them: the op log filtered to the ref. A deleted ref lists its moves; a name the\njournal records no move of is `E_REF_NOT_FOUND`.",
  "properties": {
    "before": {
      "description": "Start below this operation: the page holds the moves of operations numbered less than\nit, so the last `op` of a page reads on from there. When omitted, from the newest.",
      "format": "uint64",
      "minimum": 0,
      "type": [
        "integer",
        "null"
      ]
    },
    "limit": {
      "default": 50,
      "description": "The most moves to return: at least 1 (0 is `E_INVALID_ARG`).",
      "format": "uint",
      "minimum": 1,
      "type": "integer"
    },
    "name": {
      "description": "The ref.",
      "type": "string"
    }
  },
  "required": [
    "name"
  ],
  "title": "RefLogReq",
  "type": "object"
}
```

## Annotations

It only reads the store.

| Annotation | Value | Meaning |
| --- | --- | --- |
| `destructiveHint` | `false` | True: a tool that changes the store may overwrite or delete what is there, not only add to it. |
| `idempotentHint` | `true` | True: calling it again with the same arguments changes nothing more. |
| `openWorldHint` | `false` | True: it reaches beyond a closed set of things. Every tool here stays inside the store. |
| `readOnlyHint` | `true` | True: the tool does not change its environment, the store. |

Its entry in `tools/list` carries no `_meta`.

## CLI command

[`swarmops ref log`](../commands/ref-log.md) runs the same operation and prints the same envelope.

## Examples

### MCP

```json
{
  "id": 25,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "limit": 2,
      "name": "release/v1"
    },
    "name": "ref_log"
  }
}
```

```json
{
  "id": 25,
  "jsonrpc": "2.0",
  "result": {
    "content": [
      {
        "text": "{\"api\":1,\"meta\":{\"auth\":\"trust\",\"elapsed_ms\":\"[elapsed_ms]\",\"repo\":\"[tmp]/store\",\"resolved\":{}},\"ok\":true,\"op\":\"ref_log\",\"result\":{\"moves\":[{\"actor\":\"agent/worker-17\",\"at\":\"[at]\",\"new\":\"[c1]\",\"op\":8},{\"actor\":\"agent/worker-17\",\"at\":\"[at]\",\"old\":\"[c1]\",\"op\":7}],\"name\":\"release/v1\",\"truncated\":true}}",
        "type": "text"
      }
    ],
    "isError": false,
    "structuredContent": {
      "api": 1,
      "meta": {
        "auth": "trust",
        "elapsed_ms": "[elapsed_ms]",
        "repo": "[tmp]/store",
        "resolved": {}
      },
      "ok": true,
      "op": "ref_log",
      "result": {
        "moves": [
          {
            "actor": "agent/worker-17",
            "at": "[at]",
            "new": "[c1]",
            "op": 8
          },
          {
            "actor": "agent/worker-17",
            "at": "[at]",
            "old": "[c1]",
            "op": 7
          }
        ],
        "name": "release/v1",
        "truncated": true
      }
    }
  }
}
```

The server ran as `swarmops mcp --repo [tmp]/store --as agent/worker-17`, after `initialize`. Recorded by the MCP tests. A name in square brackets, such as `[tmp]` or `[c1]`, stands for what differs from run to run: the test's temporary directory, an id, a time, the version.

## Return information

A tool result: the envelope, whose `op` is `ref_log`, as `structuredContent` and again as the text of its one `content` block. `isError` is true exactly when the envelope's `ok` is false. On success the envelope's `result` is what [`swarmops ref log`](../commands/ref-log.md#return-information) returns.

## Errors

A failed call is a tool result with `isError: true`; the envelope's `error.code` is one of the [error codes](../errors.md).

- [`E_INVALID_ARG`](../errors.md#e_invalid_arg): arguments that do not fit `RefLogReq`, a field named twice among them included, or that break one of the server's own rules.
- [`E_NOT_A_REPO`](../errors.md#e_not_a_repo): the server's store is not there; the server serves on.
- [`E_INTERNAL`](../errors.md#e_internal): the operation panicked, a bug.

Then the errors of the operation, as [`swarmops ref log`](../commands/ref-log.md#errors) lists them.

## See also

- [`swarmops ref log`](../commands/ref-log.md)
- [MCP tools](README.md)
- [MCP integration](../../develop/mcp.md)
- [Error codes](../errors.md)