Swarm Scripts

Swarm Scripts

A swarm script is TypeScript that runs out of process with a typed Swarm SDK. Only its return value enters your context. Use one when direct tool calls would repeat, flood your context, or need deterministic processing over many records.

When to script

Named script only when the logic will run two or more times, by you, another agent, a schedule, or a workflow. A one-off goes inline, so the catalog does not fill with scratch saves.

Reference point: a workflow triage that took about 26 tool calls returns as one result of about 4k tokens in about 13 seconds.

Loading the tools

The script tools are deferred. Load them with your harness tool search before the first call: script-search, script-run, script-upsert, script-query-types, script-delete, and for durable runs launch-script-run, get-script-run, list-script-runs.

Run script-query-types before non-trivial work. It returns the live swarm-sdk.d.ts and stdlib declarations, including generated per-app types.

Seed catalog

The swarm ships named scripts at global scope. Each one replaces a multi-step tool chain. script-search with a plain-language description finds them. Call one with script-run and name plus args.

Authoring contract

The entry point takes args first and ctx second. A one-parameter function (ctx) receives args at runtime, so every ctx.* access throws. This is the most common cause of a failed run.

import type { ScriptContext } from "swarm-sdk";
import * as z from "zod";

export const argsSchema = z.object({ taskId: z.string(), limit: z.number().optional() });

export default async function (args: z.infer<typeof argsSchema>, ctx: ScriptContext) {
  const res = await ctx.swarm.task_get({ taskId: args.taskId });
  const task = ((res as { data?: unknown }).data ?? res) as { title?: string };
  return { title: task?.title };
}

• args can be undefined when a caller passes none. Guard with argsSchema.safeParse(args ?? {}) or optional chaining.
• Export a Zod argsSchema from every named script. script-upsert converts it to JSON Schema, so callers, schedules, and workflows see the input contract.
• Inline source through script-run runs without a typecheck. script-upsert typechecks before it saves. Import ScriptContext from "swarm-sdk" in inline code too, so promotion to a named script works.
• SDK methods return Promise<unknown>. Responses are usually wrapped: read res?.data ?? res. Exception: app_query with a literal appId and query returns rows typed from the app's columns.
• agentId is propagated through the X-Agent-ID header, so SDK calls run as you. taskId is not ambient: pass it in args when the script calls task_storeProgress.
• A script invoked from a workflow node may run under a workflow identity.
• Return compact structured data. Raw logs, full HTML, big JSON arrays, and file contents stay inside the script.
• Limits: about 30 s wall clock (up to 5 minutes where the tool exposes it), 1 MB stdout. Never sleep or loop past about 25 s. Chain wait-for-task calls instead.

What ctx holds

• ctx.swarm.*: the swarm SDK. task_get, task_send, task_storeProgress, task_action, task_list, slack_reply, memory_search, memory_store, kv_get, kv_getOrNull, kv_set, kv_delete, kv_incr, kv_list, swarm_get, agent_info, db_query, and more. kv_getOrNull returns the entry, null on a missing key, and throws on other errors.
• ctx.swarm.config: apiKey, agentId, mcpBaseUrl, and ctx.swarm.config.get("KEY") for user config values. All are Redacted wrappers that stringify to <redacted>. Never unwrap one into a return value, a log line, or a request body you build by hand.
• ctx.api.<slug> and ctx.mcp.<slug>: typed clients for registered connections. They exist only for registered connections. Introspect with Object.keys(ctx.api ?? {}) and Object.keys(ctx.mcp ?? {}).
• ctx.stdlib: fetch, fetchJson (retries, 30 s timeout), grep, glob, table, Redacted.
• ctx.logger: log, warn, error. Keep logs short.

Durable workflow scripts

launch-script-run runs a script as a durable, journaled run with a different ctx: ctx.run (id, agentId, args) and ctx.step.rawLlm(label, config), ctx.step.agentTask(label, config), ctx.step.swarmScript(label, config), plus ctx.swarm.*, ctx.stdlib, ctx.logger. Durable runs have no ctx.api, no ctx.mcp, and no ctx.swarm.config. Call a connection from an inner script through ctx.step.swarmScript. See the script-workflows skill.

Inline script pattern

import type { ScriptContext } from "swarm-sdk";

export default async function main(args: { status?: string; limit?: number } | undefined, ctx: ScriptContext) {
  const res: any = await ctx.swarm.task_list({ status: args?.status, limit: args?.limit ?? 50 });
  const tasks: any[] = res?.data?.tasks ?? res?.tasks ?? [];
  ctx.logger.log(`Fetched ${tasks.length} tasks`);
  return {
    total: tasks.length,
    tasks: tasks.map((task: any) => ({ id: task.id, status: task.status, title: task.task?.slice(0, 120) })),
  };
}

Named script pattern

script-upsert with a searchable name, a concrete description, and an intent that says when to choose it. Good named scripts: aggregate failures by agent, schedule, or error family; fetch and normalize a third-party API response; fan out over tasks, memories, repos, or schedules; turn noisy JSON or HTML into a compact summary.

Secrets

Order of preference:

1. A registered connection: ctx.api.<slug>.<operationId>({ path, query, header, body }) (OpenAPI), ctx.api.<slug>.graphql(query, variables) (GraphQL), ctx.mcp.<slug>.<toolName>(args) (MCP, proxied server-side, returns the raw MCP envelope: read res.structuredContent ?? res.content?.[0]?.text). Credentials attach at egress. The script never sees them. OAuth tokens refresh on their own.
2. A credential binding placeholder in a hand-written request: Authorization: Bearer [REDACTED:GITHUB_TOKEN]. The runtime substitutes the value at egress, only for the binding's allowed hosts.
3. ctx.swarm.config.get("KEY") for a config value you pass to ctx.stdlib.fetch as a header value. Still Redacted; never log it.

A raw secret, or the output of get-config with includeSecrets: true, must not appear in script source, script args, a schedule's taskTemplate or scriptArgs, or a task description. Those are stored as plain text and replayed on every run.

Registration is lead-only: script-connections and credential-bindings. A worker that needs a missing connection puts the request in its task output: slug, baseUrl or spec URL, allowedHosts, and the auth (config key or OAuth provider). Leads: upsert-openapi with a spec URL keeps operations refreshable; credential-bindings oauth-app-upsert then oauth-authorize-url sets up an OAuth provider (tokenAuthStyle and tokenBodyFormat cover Notion-style token endpoints).

Full reference: the "Script connections" guide on the docs site.

db_query for aggregation

Direct SQL beats fetching lists into the script. The parameter is sql:

const res = await ctx.swarm.db_query({ sql: "SELECT status, count(*) AS cnt FROM agent_tasks GROUP BY status" });

db_query returns positional rows: { rows: unknown[][], columns: string[] }. Zip them:

function rowsToObjects(res: any): any[] {
  const p = res?.data ?? res;
  const cols: string[] = p?.columns ?? [];
  return (p?.rows ?? []).map((r: any) =>
    Array.isArray(r) ? Object.fromEntries(cols.map((c, i) => [c, r[i]])) : r,
  );
}

Concurrency limit

ctx.swarm.db_query throttles at about three concurrent calls. A wider Promise.all fan-out can return 429 responses with no rows key, so res?.data?.rows ?? [] misreads throttling as a clean zero. Check the response status and data.error before reading rows. Serialize queries or cap concurrency at three.

Common tables: agent_tasks, session_logs, agent_memory, scheduled_tasks, agents. session_logs has no tool_name column. Tool names sit inside the content JSON column. Extract them with instr and substr in SQL, or parse the JSON in the script.

Progress from a script

export default async function main(args: { taskId: string; items: string[] }, ctx: ScriptContext) {
  await ctx.swarm.task_storeProgress({ taskId: args.taskId, progress: `Processing ${args.items.length} items` });
  return { processed: args.items.length };
}

Exposing a script as an API

A named script can serve POST /api/x/script/<id> for callers outside the swarm. Manage endpoints from the script's API tab in the dashboard, or with the script-apis tool (list, create, update, rotate, delete). list masks bearer tokens; includeSecrets: true reveals them. create and rotate return the plaintext token once.