| 1 | /** |
| 2 | * `exec.core`: a tool asking the Rust core to run one of the core's tools for it. |
| 3 | * |
| 4 | * Present on a tool's `exec` only while the call runs under the turn loop's |
| 5 | * permission gate: the model called the extension tool directly and the core |
| 6 | * gave that one call an invocation ticket (`tool/call.ticket`). A command, a |
| 7 | * timer, activation code, a sub-agent's call, and a tool run from inside |
| 8 | * `execute_tools` have no ticket, so they have no `exec.core`; the core would |
| 9 | * refuse the request anyway, and this is only the early, local answer. |
| 10 | * |
| 11 | * The host never decides anything here. `core/call` goes through `plan_tool_calls` |
| 12 | * and the approval gate exactly like a call the model makes, the approval card |
| 13 | * is composed by Rust, and the answer is either the tool's result or a typed |
| 14 | * refusal. The ticket is an opaque id the core minted for this invocation; it |
| 15 | * is passed back unchanged and never shown to the plugin by any API here. |
| 16 | */ |
| 17 | import { ErrorCode, type Json, type OwnerRef, type ToolResultWire } from '../protocol.ts' |
| 18 | import { isJson } from '../json.ts' |
| 19 | import { RpcError, type RpcPeer } from '../rpc.ts' |
| 20 | |
| 21 | /** Why the core did not run a call. */ |
| 22 | export type CoreCallFailure = |
| 23 | /** Policy: the core refuses this call outright, or the call's limits are used up. */ |
| 24 | | 'refused' |
| 25 | /** The user declined the approval card. Do not retry. */ |
| 26 | | 'denied' |
| 27 | /** The call was cancelled (the tool's own signal, a revocation, the turn). */ |
| 28 | | 'cancelled' |
| 29 | /** The core could not serve it (the host is going away, the turn ended). */ |
| 30 | | 'unavailable' |
| 31 | /** Anything else, including an input the host refused to send. */ |
| 32 | | 'failed' |
| 33 | |
| 34 | export class CoreCallError extends Error { |
| 35 | constructor( |
| 36 | readonly code: CoreCallFailure, |
| 37 | message: string, |
| 38 | ) { |
| 39 | super(message) |
| 40 | this.name = 'CoreCallError' |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | /** What a core tool returned. `isError` is the tool's own failure, not a refusal. */ |
| 45 | export interface CoreCallResult { |
| 46 | content: string |
| 47 | isError: boolean |
| 48 | structured?: Json |
| 49 | } |
| 50 | |
| 51 | export interface CoreApi { |
| 52 | /** |
| 53 | * Run the core tool `name` with `input` and wait for its result. Rejects with |
| 54 | * a `CoreCallError` when the core did not run it. `options.signal` cancels |
| 55 | * this call; the tool's own `exec.signal` always does. |
| 56 | */ |
| 57 | call(name: string, input?: Json, options?: { signal?: AbortSignal }): Promise<CoreCallResult> |
| 58 | } |
| 59 | |
| 60 | const MAX_NAME_LENGTH = 128 |
| 61 | |
| 62 | function failureFor(error: unknown): CoreCallError { |
| 63 | if (error instanceof CoreCallError) return error |
| 64 | if (error instanceof RpcError) { |
| 65 | switch (error.code) { |
| 66 | case ErrorCode.Refused: |
| 67 | return new CoreCallError('refused', error.message) |
| 68 | case ErrorCode.Denied: |
| 69 | return new CoreCallError('denied', error.message) |
| 70 | case ErrorCode.Cancelled: |
| 71 | return new CoreCallError('cancelled', error.message) |
| 72 | case ErrorCode.NotAvailable: |
| 73 | return new CoreCallError('unavailable', error.message) |
| 74 | default: |
| 75 | return new CoreCallError('failed', error.message) |
| 76 | } |
| 77 | } |
| 78 | return new CoreCallError('failed', error instanceof Error ? error.message : String(error)) |
| 79 | } |
| 80 | |
| 81 | function toResult(wire: ToolResultWire): CoreCallResult { |
| 82 | const result: CoreCallResult = { |
| 83 | content: wire.content.map((block) => block.text).join('\n'), |
| 84 | isError: wire.is_error, |
| 85 | } |
| 86 | if (wire.structured !== undefined) result.structured = wire.structured |
| 87 | return result |
| 88 | } |
| 89 | |
| 90 | /** The `exec.core` of one `tool/call` that carries `ticket`. Frozen. */ |
| 91 | export function makeCoreApi(rpc: RpcPeer, owner: OwnerRef, ticket: string, callSignal: AbortSignal): Readonly<CoreApi> { |
| 92 | return Object.freeze({ |
| 93 | async call(name: string, input: Json = {}, options: { signal?: AbortSignal } = {}): Promise<CoreCallResult> { |
| 94 | if (typeof name !== 'string' || name.length === 0 || name.length > MAX_NAME_LENGTH) { |
| 95 | throw new CoreCallError('failed', `core.call needs a tool name of 1 to ${MAX_NAME_LENGTH} characters`) |
| 96 | } |
| 97 | if (!isJson(input)) throw new CoreCallError('failed', 'core.call input must be plain JSON') |
| 98 | const signal = options.signal === undefined ? callSignal : AbortSignal.any([callSignal, options.signal]) |
| 99 | try { |
| 100 | return toResult(await rpc.request<ToolResultWire>('core/call', { owner, ticket, name, input }, signal)) |
| 101 | } catch (error) { |
| 102 | throw failureFor(error) |
| 103 | } |
| 104 | }, |
| 105 | }) |
| 106 | } |
| 107 |