Function createSystemPromptHandler

lib/hooks.ts:49–97

(
    state: SessionState,
    logger: Logger,
    config: PluginConfig,
    prompts: PromptStore,
)

]

export function createSystemPromptHandler(
    state: SessionState,
    logger: Logger,
    config: PluginConfig,
    prompts: PromptStore,
) {
    return async (
        input: { sessionID?: string; model: { limit: { context: number } } },
        output: { system: string[] },
    ) => {
        if (input.model?.limit?.context) {
            state.modelContextLimit = input.model.limit.context
            logger.debug("Cached model context limit", { limit: state.modelContextLimit })
        }

        if (state.isSubAgent && !config.experimental.allowSubAgents) {
            return
        }

        const systemText = output.system.join("\n")
        if (INTERNAL_AGENT_SIGNATURES.some((sig) => systemText.includes(sig))) {
            logger.info("Skipping DCP system prompt injection for internal agent")
            return
        }

        const effectivePermission =
            input.sessionID && state.sessionId === input.sessionID
                ? compressPermission(state, config)
                : config.compress.permission

        if (effectivePermission === "deny") {
            return
        }

        prompts.reload()
        const runtimePrompts = prompts.getRuntimePrompts()
        const newPrompt = renderSystemPrompt(
            runtimePrompts,
            buildProtectedToolsExtension(config.compress.protectedTools),
            !!state.manualMode,
            state.isSubAgent && config.experimental.allowSubAgents,
        )
        if (output.system.length > 0) {
            output.system[output.system.length - 1] += "\n\n" + newPrompt
        } else {
            output.system.push(newPrompt)
        }
    }
}

export function createChatMessageTransformHandler(
    client: any,