<!-- Generated by crates/swarmops-cli/src/reference/mcp_page.rs from the code: do not edit. Change the code, then run SWARMOPS_REGEN_REFERENCE=1 with the regen_reference test. -->

# op_log

The store's operations, newest first: each write transaction, numbered as undo takes it, with its kind, the changesets it recorded and the refs it moved; pass a limit of 20 or less and page on with before, since clients limit long tool results.

```yaml
title: "op_log"
description: "List operations."
since: "0.1.0"
mutates: false
identity_required: false
cli_command: "swarmops op log"
envelope_op: "op_log"
request_type: "OpLogReq"
annotations: {"destructiveHint":false,"idempotentHint":true,"openWorldHint":false,"readOnlyHint":true}
max_result_chars: null
```

## Input schema

`arguments` is a `OpLogReq`: `swarmops schema OpLogReq` 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 ones 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 operations to return: at least 1 (0 is `E_INVALID_ARG`). |
| `max_changesets` | integer | no | `20` | The most changesets to list for each operation; `changesets_total` counts them all. |

### 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": "`op_log` (CLI `op log`): the store's operations, newest first, a page at a time. An operation\nis one write transaction: a frame of the journal, numbered from 0 in commit order.",
  "properties": {
    "before": {
      "description": "Start below this operation: the page holds the ones numbered less than it, so the last\n`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 operations to return: at least 1 (0 is `E_INVALID_ARG`).",
      "format": "uint",
      "minimum": 1,
      "type": "integer"
    },
    "max_changesets": {
      "default": 20,
      "description": "The most changesets to list for each operation; `changesets_total` counts them all.",
      "format": "uint",
      "minimum": 0,
      "type": "integer"
    }
  },
  "title": "OpLogReq",
  "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 op log`](../commands/op-log.md) runs the same operation and prints the same envelope.

## Examples

### MCP

```json
{
  "id": 19,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "limit": 2
    },
    "name": "op_log"
  }
}
```

```json
{
  "id": 19,
  "jsonrpc": "2.0",
  "result": {
    "content": [
      {
        "text": "{\"ok\":true,\"op\":\"op_log\",\"api\":1,\"result\":{\"ops\":[{\"op\":6,\"kind\":\"ref_move\",\"changesets\":[],\"changesets_total\":0,\"ref_moves\":[{\"name\":\"release/v1\",\"old\":\"[c1]\",\"actor\":\"agent/worker-17\",\"at\":\"[at]\"}]},{\"op\":5,\"kind\":\"ref_move\",\"changesets\":[],\"changesets_total\":0,\"ref_moves\":[{\"name\":\"release/v1\",\"new\":\"[c1]\",\"actor\":\"agent/worker-17\",\"at\":\"[at]\"}]}],\"truncated\":true},\"meta\":{\"repo\":\"[tmp]/store\",\"elapsed_ms\":\"[elapsed_ms]\",\"resolved\":{},\"auth\":\"trust\"}}",
        "type": "text"
      }
    ],
    "isError": false,
    "structuredContent": {
      "api": 1,
      "meta": {
        "auth": "trust",
        "elapsed_ms": "[elapsed_ms]",
        "repo": "[tmp]/store",
        "resolved": {}
      },
      "ok": true,
      "op": "op_log",
      "result": {
        "ops": [
          {
            "changesets": [],
            "changesets_total": 0,
            "kind": "ref_move",
            "op": 6,
            "ref_moves": [
              {
                "actor": "agent/worker-17",
                "at": "[at]",
                "name": "release/v1",
                "old": "[c1]"
              }
            ]
          },
          {
            "changesets": [],
            "changesets_total": 0,
            "kind": "ref_move",
            "op": 5,
            "ref_moves": [
              {
                "actor": "agent/worker-17",
                "at": "[at]",
                "name": "release/v1",
                "new": "[c1]"
              }
            ]
          }
        ],
        "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.

## Details

Each entry is one write transaction of the store, newest first, numbered as `undo` takes it, with
its kind, the changesets it recorded and the refs it moved.
Pass a `limit` of 20 or less and page on with `before`.

## Return information

A tool result: the envelope, whose `op` is `op_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 op log`](../commands/op-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 `OpLogReq`, 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 op log`](../commands/op-log.md#errors) lists them.

## See also

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