API ReferenceAlt-Data
Identifier history
/api/v3/reference/history/{symbol}- Plan
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reference_history
IDENTIFIER HISTORY for one symbol — every identifier this security has ever been bound to, with the dates each binding started and ended, plus the dated events where the ISSUER changed its name, ticker or CUSIP. This is the part of a crosswalk a current-state table cannot give you: it answers 'what was this on 2015-06-30', 'when did this CUSIP change' and 'what was this company called then'. Returns the timeline grouped by identifier rung (each entry with valid_from, valid_thru and whether it is still current), the issuer change events with what changed at each one, and — with as_of — the security that held the symbol on that date and the exact set of identifiers in force then. Use it to back-map a historical holdings file, to audit identifier drift in your own data, or to explain a ticker that no longer exists. STALENESS, stated rather than implied: the issuer change log is a VINTAGE snapshot that lags the live security master (as-of 2026-04-20 when this shipped, 104 days old, newest change event 2026-01-30). Its age in days and its expected cadence are in every response, and any disagreement between it and the live spine is named explicitly rather than blended into one confident answer. Coverage is a number, measured in every response: the identifier bindings on file, how many are retired, and how many securities carry at least one prior ticker.
Parameters
Path
symbolstringRequiredQuery
as_ofstringOptionalYYYY-MM-DD — also return the identifiers in force on that date.
prefer_countrystringOptionalDisambiguation policy for a shared symbol, e.g. USA.
include_change_logbooleanOptionalInclude the dated issuer name/ticker/CUSIP change events (a VINTAGE — its age is reported)
trueResponse
A 200 is a JSON envelope: ok: true and this endpoint's own fields (see Introduction). It carries X-Request-ID, the credit headers (X-Credits-Cost, X-Credits-Remaining, X-Credits-Receipt, X-Credits-Settlement) and the rate-limit headers.
A 200 is billed even when it holds no data (an empty list, null, found: false), so check those fields. Pricing & credits explains the credit headers.
Errors
No error is billed. The body is { "ok": false, "error", "detail", "request_; read the code from error.
| Error | Meaning |
|---|---|
400 invalid_ticker | The request is malformed, for example a ticker that is not a symbol: invalid_ticker, refused before any credit is reserved, with param naming the parameter. Not billed. |
401 unauthorized | Missing or invalid API key. |
402 plan_required | Your plan does not include this tool, you are out of credits, or your workspace's spend cap paused its keys. plan_required names the plan that unlocks the tool; usage_exceeded means the credit balance is spent; spend_cap_reached means the key is paused until the cap resets or is raised: detail names the cap and the reset, cap_usd and resets_at (ISO 8601) carry them, and doc_url links pricing and credits. Not billed. |
403 scope_denied | This API key is limited to some products and this tool is not one of them. product names the tool's product and scopes the key's products. An upgrade does not change it: use a key whose scopes include the product, or change this key's scopes. Not billed. |
404 not_found | No such resource. Not billed. |
422 validation | A parameter is missing, out of range or the wrong type; param names it. Not billed. |
429 rate_limited | Your plan's rate limit is spent for this window. Retry after Retry-After seconds. Not billed. |
503 paid_ | The data could not be served completely right now; retry later. Not billed. |
504 request_timeout | The request ran past the server's time budget; retry. Not billed. |
This table lists what the spec declares for this route. Error responses lists every code FIRM sends, with when to retry.