> ## Documentation Index > Fetch the complete documentation index at: https://e818172-opencomputer.manicule.dev/llms.txt > Use this file to discover all available pages before exploring further. > For every page in one file, fetch https://e818172-opencomputer.manicule.dev/llms-full.txt (large). > To search and read these docs as tools, connect the MCP server at https://e818172-opencomputer.manicule.dev/api/mcp. > Every agent surface: https://e818172-opencomputer.manicule.dev/.well-known/llms-manifest.json # Agent tools (/reference/agent-tools) Related: [Slack commands](/reference/slack-commands.md), [Configuration](/reference/configuration.md), [Limits and defaults](/reference/limits.md), [API schema](/reference/api-schema.md) > Every tool Computer adds to the harness, with parameters and per-runner limits Under Claude Code these tools are one MCP server named `calvin`; approval prompts show the full id, `mcp__calvin__`. ## Availability | Tool | One-machine mode (`npm start`) | Self-hosted gateway and host | Hosted | | ---------------------- | ------------------------------ | ------------------------------------------------------------------- | ------ | | `send_file` | yes | yes | yes | | `post_card` | yes | yes | yes | | `checkout_repo` | no | when the host has a workspace definition | yes | | `spawn_thread` | no | yes | yes | | `read_thread` | no | yes | yes | | `post_thread` | no | yes | yes | | `request_secret` | no | yes; fails unless the gateway has `SP_STORE_KEY` | yes | | `preview`, `unpreview` | no | offered, but the gateway refuses the call (see [preview](#preview)) | yes | "Per runner" counts reset when the session's runner restarts. ## send_file Posts a file into the session's Slack thread. PNG, JPEG, GIF and WebP images render inline. | Parameter | Type | Required | Meaning | | ---------- | ------------------------------ | -------- | ----------------------------------------------- | | `path` | string | yes | Absolute, or relative to the session directory. | | `comment` | string, up to 3,000 characters | no | Message posted with the file. | | `title` | string, up to 200 characters | no | Defaults to the file name. | | `alt_text` | string, up to 1,000 characters | no | Image description for screen readers. | | Rule | Value | | ------------- | ---------------------------------------------------------------------------------------------- | | File | Regular, non-empty, at most 100 MiB, inside the session directory or the system temp directory | | Count | 50 files per runner | | Secrets | A file that contains the value of one of the session's secrets is refused | | Slack scope | `files:write` | | From a script | `calvin-send-file [comment]`, on the runner's `PATH`, same limits | ## post_card Posts a card (key facts, a table, charts, link buttons) into the session's thread as Slack blocks. | Parameter | Type | Required | Meaning | | --------------- | ------ | -------- | -------------------------------- | | `spec` | object | yes | The card. | | `spec.root` | string | yes | Id of the root element, a Card. | | `spec.elements` | map | yes | Id to `{type, props, children}`. | | `spec.state` | object | no | | | Rule | Value | | ------------ | -------------------------------------------------------------------------------- | | Table | One; 100 rows, 20 columns | | Charts | Two; title up to 50 characters, 12 series, 20 points, labels up to 20 characters | | Fields | 10 | | Slack blocks | 50 | | Buttons | Links only | | Invalid spec | Refused with the list of problems | | Count | 50 cards per runner | | Secrets | As for `send_file` | ## checkout_repo Adds workspace repositories to the session directory, each as a git worktree on the session's branch, cloning first if needed. A repository already checked out is returned as it is. See Repositories. | Parameter | Type | Required | Meaning | | --------- | ------------------------ | -------- | ------------------------------------------------------------------------- | | `repos` | array of 1 to 10 strings | yes | Repository names from the definition, or `owner/name` (case-insensitive). | | Error | Cause | | --------------------------------------------------------------- | -------------------------------------- | | `no repository in this workspace; the list is in AGENTS.md` | Not in the definition | | ` is not published yet` | The repository is marked `unpublished` | ## spawn_thread Starts a session in a new Slack thread, with the same owner and permission mode. The gateway posts the task and a link to the brief as a top-level message in the parent's channel, or in the owner's direct messages when the parent is a code channel. See [Linked and spawned threads](/slack/linked-and-spawned-threads). | Parameter | Type | Required | Meaning | | --------- | ------------------------------------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------------------- | | `task` | string, 3 to 150 characters, one line | yes | What the new thread should do. | | `brief` | string | yes | Path of a `.md` file inside the session directory, relative to it, with an optional `#anchor`. Must be on the fetched default branch of its repository. | | `model` | `smart`, `fast` or `default` | no | Model tier. Omitted: the parent's model. | Limit: 8 per runner. ## read_thread Returns a Slack thread's first message, its latest replies (at most 40, 16,000 characters in all, 4,000 per message) and how many were left out, marked as data, not instructions. See [Linked and spawned threads](/slack/linked-and-spawned-threads). | Parameter | Type | Required | Meaning | | --------- | ------ | ----------------------------- | ---------------------------------------------------------------------- | | `url` | string | `url`, or `channel` with `ts` | The thread's Slack link. | | `channel` | string | | Channel id (`C…` or `G…`). | | `ts` | string | | Timestamp of a message in the thread, for example `1700000000.000100`. | | Rule | Value | | ---------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------- | | Count | 40 per runner | | Approval | Never asked | | Readable conversations | The bot is in it, and the session's owner and everyone who can read the session's own conversation can see it. Otherwise the tool returns the reason. | ## post_thread Posts a reply inside another Slack thread, never at the channel's top level. | Parameter | Type | Required | Meaning | | ----------------------------- | ----------------------------- | -------- | ------------------------ | | `url`, or `channel` with `ts` | as for `read_thread` | yes | The thread to post into. | | `text` | string, 1 to 4,000 characters | yes | Slack mrkdwn. | | Rule | Value | | --------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------- | | Count | 20 per runner | | Approval | Asked outside `bypassPermissions` mode (see [Permission modes](/slack/permission-modes)) | | Channel-wide mentions (`@channel`, `@here`, `@everyone`, user groups) | Become plain text | | Attribution | The gateway appends a `Posted for` line naming the session's owner and linking the session's thread | ## request_secret Posts a button; the person types the secret into a private Slack form. The agent ends its turn and is told when the secret is set; the value is then in the environment of the session's next shell commands. See [Secrets and variables](/slack/secrets-and-variables). | Parameter | Type | Required | Meaning | | --------- | ------------------------------------ | -------- | --------------------------------------------------- | | `name` | string, an environment variable name | yes | For example `STRIPE_API_KEY`. | | `reason` | string, 3 to 200 characters | yes | One line shown to the person. | | `file` | boolean | no | Store the secret as a file; `$NAME` holds its path. | Limit: 10 per runner. Fails when a secret of that name is already set, or when a self-hosted gateway has no `SP_STORE_KEY`. ## preview Gives an HTTP server listening on a port of the computer a public URL. Anyone with the URL can open it. Plain HTTP on that port only; the URL works while the server runs. See [Preview URLs](/slack/preview-urls). | Parameter | Type | Required | Meaning | | --------- | ------------------------------------------------------------------------------- | -------- | ------------------------------------------------------ | | `port` | integer, 1 to 65535 | yes | The port the server listens on, on localhost. | | `name` | string, one DNS label (lowercase letters, digits, hyphens; up to 63 characters) | no | Omitted: a generated name, or the port's existing one. | Returns the URL, the name, and whether something was listening on the port. ## unpreview Takes down a preview URL. | Parameter | Type | Required | Meaning | | --------- | ------ | -------- | ------------------------------------------------------ | | `name` | string | yes | The preview's name, the label at the start of its URL. |