A vendor instrument is an id scheme, an id and a field
Table of Contents
1. Summary
A vendor instrument names one value that a provider publishes. It has an id
scheme, an external id and a field. The system uses the vendor's own
conventions for all three, so a live adapter and the simulator publish the same
names. Where the system must invent an id, it sets the minted flag and writes
down why.
2. Detail
2.1. The three parts
| Part | Example (Bloomberg) | Example (LSEG) |
|---|---|---|
| Id scheme | bbg_ticker |
ric |
| External id | EURUSD Curncy |
EUR= |
| Field | PX_LAST |
BID |
The scheme says how to read the id. The field says which value of the instrument is meant, because one instrument carries many values.
2.2. Follow the vendor
The rule is to match the vendor's conventions. The survey of the notation of each vendor is External market data identifiers. A catalogue row holds the id exactly as the vendor writes it, including spaces and punctuation. Encoding for NATS happens in the subject and never in the stored id. See The adapter subjects.
2.3. The minted flag
Sometimes the vendor has no single id for what the system needs. An example is
one pillar of a curve that a vendor publishes only as a chain. The system then
mints an id in the vendor's style, sets minted to true, and records the reason
in the row's deviation_note. A live adapter must map a minted id to the
vendor's real way of asking. A reader can list all minted ids per provider.
2.4. The row
| Column | Meaning |
|---|---|
provider |
The owner of the namespace |
id_scheme |
How to read the id |
external_id |
The id in the vendor's notation |
field |
The value of the instrument |
minted |
True when the system invented the id |
deviation_note |
Why the id differs from the vendor's, when minted is true |
3. See also
- Market Data Architecture — the structure note that orders this cluster.
- The mapping belongs to the provider and not to the source — completes: how a vendor instrument becomes an internal item.
- External market data identifiers — completes: the survey of vendor notations.