What the data for this category looks like
Coal transportation and sales business data primarily comes from internal sales and transportation management systems, weighing ledgers, coal purchase and sales contracts, railway/road shipping dispatch logs. Data is synchronized in real time upon completion of a single shipment, or full waybill data is updated in daily batches. Core fields for a single business document include contract number, coal type name, shipment tonnage, consignee unit, weighing time, freight unit price, rail car/vehicle number. Field units are mostly tons, yuan per ton, trips, hours.
What constraints these characteristics impose on multi-turn dialogue and prompt engineering
Coal transportation and sales business has many data fields and specialized units. Multi-turn dialogue must accurately match the specific waybill corresponding to user queries, so business context must be bound via session identifiers. Single shipment data volume is large, overly long dialogue history will consume LLM token quotas, so context length must be limited. Business data updates frequently, so dialogue history must sync the latest waybill status to avoid referencing expired information. Additionally, prompt engineering must clearly specify rules for extracting business fields, to ensure that information from different coal types and shipment batches is not confused during multi-turn interactions.
How to set configurations
| Configuration Item | Recommended Setting | Rationale |
|---|---|---|
| Maximum Context Window | First 10 dialogue turns + most recent 2000 characters | Single waybill data volume for coal transportation and sales is large, overly long context will consume token quotas. Limiting turn count and character count prevents overflow |
variables bound fields | Bind contract number, coal type, shipment tonnage, weighing time | Core fields for coal transportation and sales business are fixed. Binding these fields allows direct calls in prompt engineering, avoiding repeated queries to users |
messages history truncation rule | Truncate the earliest non-core dialogue turns when context exceeds 2000 characters | Retains recent business context while controlling token usage, ensuring LLM response efficiency |
chatId session binding | Bind unique waybill identifier | Ensures coherent context for multi-turn dialogue about the same waybill, avoiding confusion between queries from different business batches |
| Prompt template variable replacement | Calibrate based on actual testing | Must adapt to specialized business terms for coal transportation and sales, such as "rail car number" and "platform number", to ensure LLM understands the business scenario |
Three common mistakes
- Phenomenon: No corresponding business session record exists in MongoDB-stored dialogue history. Cause:
chatIdwas not bound to the unique waybill identifier, resulting in session data not being aggregated and stored by business dimension. - Phenomenon: Knowledge base search works correctly during debugging, but AI dialogue responses do not reference business knowledge base content. Cause: Current waybill business data was not correctly passed to the prompt context via
variables, leading to retrieval scope deviating from the target business scenario. - Phenomenon: Output results from program execution modules cannot be passed as background knowledge to the next dialogue turn. Cause: Execution results were not appended to dialogue history via
messages, causing subsequent LLMs to be unable to access previously executed output content.
How to confirm proper configuration
- Initiate a query containing core waybill fields, check whether the values of fields bound via
variablesare correctly carried in the dialogue history panel. - Log into the corresponding MongoDB collection, confirm that session records indexed by
chatIdexist, and that the records contain complete business context. - Trigger the program execution module, check whether the text content of execution results is appended to the dialogue history.
- In the debugging panel of FastGPT v4.17.0, adjust the context length threshold, verify that the earliest non-core dialogue turns are automatically truncated when the threshold is exceeded.
The values provided here are common starting points, and should be evaluated against the reader's own samples.
Question material comes from public community discussions. Configuration values are common starting points and should be measured against your own samples. Verified on 2026-09-28.