Files
deepseek-harness/packages/core/agent-loop/src/invariant.ts

64 lines
3.0 KiB
TypeScript

/**
* Package-owned request-reconstruction invariant for loop-built LLM calls.
* @module @deepseek-ai/dsh-agent-loop/invariant
*/
import type { Context } from 'cordis'
import { isAgentLoopRequest, type GenerateOptions } from '@deepseek-ai/dsh-llm'
import type { InvariantFailure, InvariantInstaller } from '@deepseek-ai/dsh-invariants'
import { foldRequestHeader } from '@deepseek-ai/dsh-session'
const PACKAGE_NAME = '@deepseek-ai/dsh-agent-loop'
/** Cordis companion plugin name. */
export const name = 'agent-loop-invariant'
/** Service required before the companion can reserve package ownership. */
export const inject = ['invariants']
/** Install the request-reconstruction contribution into its child registration fiber. */
const install: InvariantInstaller = Object.assign((ctx: Context, fail: InvariantFailure) => {
// Prepend prevents a short-circuiting replay listener from silencing the check.
ctx.on('llm/stream', (options: GenerateOptions, next) => {
if (!isAgentLoopRequest(options)) return next()
if (!Object.isFrozen(options)) fail('a loop-built request must be frozen')
if (options.sessionId === undefined) fail('a loop-built request must carry a session id')
const session = ctx.sessions.get(options.sessionId)
if (!session) fail(`a loop-built request must carry a live session id, got "${String(options.sessionId)}"`)
if (!Object.isFrozen(options.messages)) {
fail('a loop-built request must carry a frozen messages array')
}
const events = session.events
if (!events.some(event => event.type === 'step/start')) {
return fail('a loop-built request with no step/start in its session log')
}
const header = foldRequestHeader(events)
if (header === undefined) {
return fail('a loop-built request with no request/header event in its session log')
}
const expected = session.deriveMessages()
if (JSON.stringify(options.messages) !== JSON.stringify(expected)) {
fail(`llm request for session "${String(session.id)}" diverges from the dispatch-time durable derivation (log-reconstruction desync)`)
}
const headerMatches = options.model === header.config.model
&& options.system === header.system
&& options.temperature === header.config.temperature
&& options.maxTokens === header.config.maxTokens
&& JSON.stringify(options.stop) === JSON.stringify(header.config.stop)
&& JSON.stringify(options.tools ?? []) === JSON.stringify(header.tools ?? [])
if (!headerMatches) {
fail(`llm request for session "${String(session.id)}" diverges from the folded request header`)
}
return next()
}, { global: true, prepend: true })
}, { inject: ['sessions'] })
/**
* Register the agent-loop invariant companion.
* @param ctx - Cordis context carrying the invariant service.
* @returns the installed registration's disposer after setup succeeds.
*/
export const apply = (ctx: Context): Promise<() => void> =>
Promise.resolve(ctx.invariants.register(PACKAGE_NAME, install))