# FRED — Zapi reference

> Federal Reserve Economic Data: macro series with point-in-time vintages, so a revised print never masquerades as the original.

**Base URL:** `https://api.zpi.web.id`
**Auth:** Send `x-api-key: YOUR_KEY` header on every request. Get a free key at https://zpi.web.id/dashboard/keys.
**Response envelope:** `{ content, message, errors }`
**Rate limit:** 60 req/min on free tier.

**Related:**
- Detail page: https://zpi.web.id/api/finance/fred
- Endpoint catalog: https://zpi.web.id/category/finance
- Concise index: https://zpi.web.id/llms.txt
- Full reference: https://zpi.web.id/llms-full.txt

---

## FRED

**Category:** finance · **Slug:** `fred`
**Detail page:** https://zpi.web.id/api/finance/fred

Federal Reserve Economic Data: macro series with point-in-time vintages, so a revised print never masquerades as the original.

**Tags:** fred, macro, economics, time-series, rates, point-in-time

### Category

Walk the FRED category tree: child categories at a node, and the series that

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/category`
- **Cache TTL:** 21600s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `category` | number | query | no | FRED category id. Omit for the root of the tree. |
| `page` | number | query | no | Page of the series listing (default 1) |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/category?category=115&page=1" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/category?category=115&page=1", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/category?category=115&page=1",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "page": 1,
  "count": 50,
  "items": [
    {
      "url": "https://fred.stlouisfed.org/series/DGS10",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis",
      "units": "Percent",
      "series": "DGS10",
      "frequency": "Daily",
      "observationEnd": "2026-08-18",
      "observationStart": "1962-01-02",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/GS10",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis",
      "units": "Percent",
      "series": "GS10",
      "frequency": "Monthly",
      "observationEnd": "Jul 2026",
      "observationStart": "Apr 1953",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/WGS10YR",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis",
      "units": "Percent",
      "series": "WGS10YR",
      "frequency": "Weekly",
      "observationEnd": "2026-08-14",
      "observationStart": "1962-01-05",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/RIFLGFCY10NA",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis",
      "units": "Percent",
      "series": "RIFLGFCY10NA",
      "frequency": "Annual",
      "observationEnd": "2025",
      "observationStart": "1962",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/DFII10",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "DFII10",
      "frequency": "Daily",
      "observationEnd": "2026-08-18",
      "observationStart": "2003-01-02",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/FII10",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "FII10",
      "frequency": "Monthly",
      "observationEnd": "Jul 2026",
      "observationStart": "Jan 2003",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    }
  ],
  "total": null,
  "dataset": "category",
  "hasMore": true,
  "category": 115,
  "children": [
    {
      "name": "Money, Banking, & Finance",
      "categoryId": 32991
    },
    {
      "name": "Interest Rates",
      "categoryId": 22
    }
  ],
  "nextPage": 2,
  "provider": "fred"
}
```

---

### Observations Vintage

Point-in-time observations — what a series looked like on the day it was

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/observations-vintage`
- **Cache TTL:** 21600s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `series` | string | query | no | FRED series ids, comma-separated. A missing observation comes back as null, never 0. Default GDP. |
| `vintages` | string | query | no | Vintage dates, comma-separated, YYYY-MM-DD. List them with the `vintage-dates` endpoint. Series times vintages must not exceed 12. Defaults to the latest vintage. |
| `from` | string | query | no | First observation date, YYYY-MM-DD. |
| `to` | string | query | no | Last observation date, YYYY-MM-DD. |
| `length` | number | query | no | Observations to return, newest first (default 100, max 20000) |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/observations-vintage?series=GDP&vintages=2020-01-30%2C2020-04-29%2C2026-07-30&from=2019-07-01&to=2019-12-31&length=100" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/observations-vintage?series=GDP&vintages=2020-01-30%2C2020-04-29%2C2026-07-30&from=2019-07-01&to=2019-12-31&length=100", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/observations-vintage?series=GDP&vintages=2020-01-30%2C2020-04-29%2C2026-07-30&from=2019-07-01&to=2019-12-31&length=100",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "to": "2019-12-31",
  "from": "2019-07-01",
  "count": 2,
  "items": [
    {
      "date": "2019-10-01",
      "values": {
        "GDP": 21933.217
      }
    },
    {
      "date": "2019-07-01",
      "values": {
        "GDP": 21717.171
      }
    }
  ],
  "total": 2,
  "series": [
    "GDP"
  ],
  "columns": [
    {
      "key": "GDP",
      "column": "GDP_20260820",
      "series": "GDP"
    }
  ],
  "dataset": "observations-vintage",
  "missing": [],
  "provider": "fred",
  "vintages": []
}
```

---

### Release Dates

The US statistical release calendar — what is published on a given day, at what

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/release-dates`
- **Cache TTL:** 3600s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `from` | string | query | no | First calendar date, YYYY-MM-DD. Defaults to today. |
| `to` | string | query | no | Last calendar date, YYYY-MM-DD. Defaults to `from`. |
| `release` | number | query | no | Restrict to one release id, from the `releases` endpoint. |
| `year` | number | query | no | Whole calendar year. Use with `release`; overrides `from`/`to`. |
| `page` | number | query | no | Page of the calendar, 50 entries each (default 1) |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/release-dates?from=2026-08-17&to=2026-08-21&release=18&year=2026&page=1" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/release-dates?from=2026-08-17&to=2026-08-21&release=18&year=2026&page=1", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/release-dates?from=2026-08-17&to=2026-08-21&release=18&year=2026&page=1",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "to": "2026-08-21",
  "from": "2026-08-17",
  "page": 1,
  "year": 2026,
  "count": 50,
  "items": [
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "date": "2026-01-02",
      "name": "H.15 Selected Interest Rates",
      "time": "3:15 pm",
      "released": true,
      "releaseId": 18
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "date": "2026-01-05",
      "name": "H.15 Selected Interest Rates",
      "time": "3:15 pm",
      "released": true,
      "releaseId": 18
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "date": "2026-01-06",
      "name": "H.15 Selected Interest Rates",
      "time": "3:15 pm",
      "released": true,
      "releaseId": 18
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "date": "2026-01-07",
      "name": "H.15 Selected Interest Rates",
      "time": "3:15 pm",
      "released": true,
      "releaseId": 18
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "date": "2026-01-08",
      "name": "H.15 Selected Interest Rates",
      "time": "3:15 pm",
      "released": true,
      "releaseId": 18
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "date": "2026-01-09",
      "name": "H.15 Selected Interest Rates",
      "time": "3:15 pm",
      "released": true,
      "releaseId": 18
    }
  ],
  "total": null,
  "dataset": "release-dates",
  "hasMore": true,
  "release": 18,
  "nextPage": 2,
  "provider": "fred"
}
```

---

### Releases

The release catalogue — every statistical publication FRED redistributes,

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/releases`
- **Cache TTL:** 86400s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `page` | number | query | no | Catalogue page, 50 releases each (default 1) |
| `query` | string | query | no | Keep only releases whose name contains this text. |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/releases?page=1&query=interest%20rates" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/releases?page=1&query=interest%20rates", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/releases?page=1&query=interest%20rates",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "page": 1,
  "count": 4,
  "items": [
    {
      "url": "https://fred.stlouisfed.org/release?rid=131",
      "name": "G.13 Selected Interest Rates",
      "releaseId": 131
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=18",
      "name": "H.15 Selected Interest Rates",
      "releaseId": 18
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=484",
      "name": "Key ECB Interest Rates",
      "releaseId": 484
    },
    {
      "url": "https://fred.stlouisfed.org/release?rid=94",
      "name": "Survey of Secondary Market Prices and Yields, and Interest Rates for Home Loans",
      "releaseId": 94
    }
  ],
  "query": "interest rates",
  "total": null,
  "dataset": "releases",
  "hasMore": false,
  "nextPage": null,
  "provider": "fred"
}
```

---

### Series Observations

FRED observations — any economic series the St. Louis Fed publishes, by id.

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/series-observations`
- **Cache TTL:** 3600s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `series` | string | query | no | FRED series ids, comma-separated, up to 12 — the upstream drops the 13th silently. A missing observation comes back as null, never 0. Default DGS10. |
| `from` | string | query | no | First observation date, YYYY-MM-DD. Applied to every series. |
| `to` | string | query | no | Last observation date, YYYY-MM-DD. Applied to every series. |
| `transformation` | enum(lin|chg|ch1|pch|pc1|pca|cch|cca|log) | query | no | Server-side transform: lin (level), chg, ch1, pch, pc1 (year-over-year %), pca, cch, cca, log. Default lin. |
| `frequency` | enum(Daily|Weekly|Biweekly|Monthly|Quarterly|Semiannual|Annual) | query | no | Resample a higher-frequency series down to Daily, Weekly, Biweekly, Monthly, Quarterly, Semiannual or Annual. |
| `aggregation` | enum(avg|sum|eop) | query | no | How `frequency` collapses each bucket: avg, sum or eop (end of period). Default avg. |
| `length` | number | query | no | Observations to return, newest first (default 100, max 20000) |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/series-observations?series=DGS10%2CDGS2%2CT10Y2Y&from=2026-01-01&to=2026-08-18&transformation=pc1&frequency=Monthly&aggregation=avg&length=100" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/series-observations?series=DGS10%2CDGS2%2CT10Y2Y&from=2026-01-01&to=2026-08-18&transformation=pc1&frequency=Monthly&aggregation=avg&length=100", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/series-observations?series=DGS10%2CDGS2%2CT10Y2Y&from=2026-01-01&to=2026-08-18&transformation=pc1&frequency=Monthly&aggregation=avg&length=100",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "to": "2026-08-01",
  "from": "2024-01-01",
  "count": 100,
  "items": [
    {
      "date": "2026-07-31",
      "values": {
        "DFII10": 2.47
      }
    },
    {
      "date": "2026-07-30",
      "values": {
        "DFII10": 2.41
      }
    },
    {
      "date": "2026-07-29",
      "values": {
        "DFII10": 2.41
      }
    },
    {
      "date": "2026-07-28",
      "values": {
        "DFII10": 2.41
      }
    },
    {
      "date": "2026-07-27",
      "values": {
        "DFII10": 2.44
      }
    },
    {
      "date": "2026-07-24",
      "values": {
        "DFII10": 2.43
      }
    }
  ],
  "total": 674,
  "series": [
    "DFII10"
  ],
  "dataset": "series-observations",
  "missing": [],
  "provider": "fred",
  "resolved": [
    "DFII10"
  ],
  "transformation": "lin"
}
```

---

### Series Search

Free-text search across the FRED catalogue — the way to turn "10-year real

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/series-search`
- **Cache TTL:** 86400s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `query` | string | query | yes | Free text. Matches series titles, notes and tags. Required. |
| `page` | number | query | no | Result page (default 1, upstream stops at 30) |
| `sort` | enum(relevance|popularity|title|frequency|units|seasonality|updated|start|end) | query | no | Result ordering. Default relevance. |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/series-search?query=10-year%20real%20yield&page=1&sort=popularity" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/series-search?query=10-year%20real%20yield&page=1&sort=popularity", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/series-search?query=10-year%20real%20yield&page=1&sort=popularity",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "page": 1,
  "count": 6,
  "items": [
    {
      "url": "https://fred.stlouisfed.org/series/DFII10",
      "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "DFII10",
      "frequency": "Daily",
      "description": "View data of the inflation-adjusted interest rates on 10-year Treasury securities with a constant maturity.",
      "observationEnd": "2026-08-18",
      "observationStart": "2003-01-02",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/DFII5",
      "title": "Market Yield on U.S. Treasury Securities at 5-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "DFII5",
      "frequency": "Daily",
      "description": "H.15 Statistical Release notes (https://www.federalreserve.gov/releases/h15/default.htm) and the Treasury Yield Curve Methodology (https://home.treasury.gov/policy-issues/financing-the-government/interest-rate-statistics/treasury-yield-curve-methodology). For questions on the data, please contact the data source (https://www.federalreserve.gov/apps/ContactUs/feedback.aspx?refurl=/releases/h15/%). For questions on FRED functionality, please contact us here (https://fred.stlouisfed.org/contactus/).</p>",
      "observationEnd": "2026-08-18",
      "observationStart": "2003-01-02",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/DFII30",
      "title": "Market Yield on U.S. Treasury Securities at 30-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "DFII30",
      "frequency": "Daily",
      "description": "H.15 Statistical Release notes (https://www.federalreserve.gov/releases/h15/default.htm) and the Treasury Yield Curve Methodology (https://home.treasury.gov/policy-issues/financing-the-government/interest-rate-statistics/treasury-yield-curve-methodology). For questions on the data, please contact the data source (https://www.federalreserve.gov/apps/ContactUs/feedback.aspx?refurl=/releases/h15/%). For questions on FRED functionality, please contact us here (https://fred.stlouisfed.org/contactus/).</p>",
      "observationEnd": "2026-08-18",
      "observationStart": "2010-02-22",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/DLTIIT",
      "title": "Treasury Long-Term Average (Over 10 Years), Inflation-Indexed",
      "units": "Percent",
      "series": "DLTIIT",
      "frequency": "Daily",
      "description": "data source (https://www.federalreserve.gov/apps/ContactUs/feedback.aspx?refurl=/releases/h15/%). For questions on FRED functionality, please contact us here (https://fred.stlouisfed.org/contactus/).</p>",
      "observationEnd": "2026-08-18",
      "observationStart": "2000-01-03",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/DFII20",
      "title": "Market Yield on U.S. Treasury Securities at 20-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "DFII20",
      "frequency": "Daily",
      "description": "H.15 Statistical Release notes (https://www.federalreserve.gov/releases/h15/default.htm) and the Treasury Yield Curve Methodology (https://home.treasury.gov/policy-issues/financing-the-government/interest-rate-statistics/treasury-yield-curve-methodology). For questions on the data, please contact the data source (https://www.federalreserve.gov/apps/ContactUs/feedback.aspx?refurl=/releases/h15/%). For questions on FRED functionality, please contact us here (https://fred.stlouisfed.org/contactus/).</p>",
      "observationEnd": "2026-08-18",
      "observationStart": "2004-07-27",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    },
    {
      "url": "https://fred.stlouisfed.org/series/DFII7",
      "title": "Market Yield on U.S. Treasury Securities at 7-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
      "units": "Percent",
      "series": "DFII7",
      "frequency": "Daily",
      "description": "H.15 Statistical Release notes (https://www.federalreserve.gov/releases/h15/default.htm) and the Treasury Yield Curve Methodology (https://home.treasury.gov/policy-issues/financing-the-government/interest-rate-statistics/treasury-yield-curve-methodology). For questions on the data, please contact the data source (https://www.federalreserve.gov/apps/ContactUs/feedback.aspx?refurl=/releases/h15/%). For questions on FRED functionality, please contact us here (https://fred.stlouisfed.org/contactus/).</p>",
      "observationEnd": "2026-08-18",
      "observationStart": "2003-01-02",
      "seasonalAdjustment": "Not Seasonally Adjusted"
    }
  ],
  "query": "real yield",
  "total": null,
  "dataset": "series-search",
  "hasMore": false,
  "nextPage": null,
  "provider": "fred"
}
```

---

### Series

Metadata for one FRED series — units, frequency, seasonal adjustment, the

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/series`
- **Cache TTL:** 21600s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `series` | string | query | no | One FRED series id. Case-insensitive. Default DGS10. |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/series?series=DGS10" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/series?series=DGS10", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/series?series=DGS10",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "url": "https://fred.stlouisfed.org/series/DFII10",
  "notes": "For further information regarding treasury constant maturity data, please refer to the H.15 Statistical Release notes and the Treasury Yield Curve Methodology . For questions on the data, please contact the data source . For questions on FRED functionality, please contact us here .",
  "title": "Market Yield on U.S. Treasury Securities at 10-Year Constant Maturity, Quoted on an Investment Basis, Inflation-Indexed",
  "units": "Percent",
  "series": "DFII10",
  "source": "Board of Governors of the Federal Reserve System (US)",
  "dataset": "series",
  "license": "https://fred.stlouisfed.org/legal/#copyright-public-domain",
  "release": {
    "name": "H.15 Selected Interest Rates",
    "releaseId": 18
  },
  "keywords": [
    "tips",
    "10-year",
    "maturity",
    "h15",
    "treasury",
    "securities"
  ],
  "provider": "fred",
  "frequency": "Daily",
  "copyrighted": false,
  "description": "View data of the inflation-adjusted interest rates on 10-year Treasury securities with a constant maturity.",
  "lastUpdated": "2026-08-19T15:16:00-05:00",
  "categoryPath": [
    {
      "name": "Money, Banking, & Finance",
      "categoryId": 32991
    },
    {
      "name": "Interest Rates",
      "categoryId": 22
    },
    {
      "name": "Treasury Inflation-Indexed Securities",
      "categoryId": 82
    },
    {
      "name": "Treasury Constant Maturity",
      "categoryId": 115
    }
  ],
  "nextReleaseDate": "2026-08-20",
  "seasonalAdjustment": "Not Seasonally Adjusted",
  "lastObservationDate": "2026-08-18",
  "lastObservationValue": 2.41,
  "lastObservationPeriod": "2026-08-18"
}
```

---

### Sources

The publishers behind the catalogue — statistical agencies, central banks and

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/sources`
- **Cache TTL:** 86400s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `page` | number | query | no | Catalogue page, 50 sources each (default 1) |
| `query` | string | query | no | Keep only sources whose name contains this text. |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/sources?page=1&query=federal%20reserve" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/sources?page=1&query=federal%20reserve", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/sources?page=1&query=federal%20reserve",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "page": 1,
  "count": 12,
  "items": [
    {
      "url": "https://fred.stlouisfed.org/source?soid=1",
      "name": "Board of Governors of the Federal Reserve System (US)",
      "sourceId": 1
    },
    {
      "url": "https://fred.stlouisfed.org/source?soid=91",
      "name": "Federal Reserve Bank of Atlanta",
      "sourceId": 91
    },
    {
      "url": "https://fred.stlouisfed.org/source?soid=54",
      "name": "Federal Reserve Bank of Chicago",
      "sourceId": 54
    },
    {
      "url": "https://fred.stlouisfed.org/source?soid=90",
      "name": "Federal Reserve Bank of Cleveland",
      "sourceId": 90
    },
    {
      "url": "https://fred.stlouisfed.org/source?soid=89",
      "name": "Federal Reserve Bank of Dallas",
      "sourceId": 89
    },
    {
      "url": "https://fred.stlouisfed.org/source?soid=46",
      "name": "Federal Reserve Bank of Kansas City",
      "sourceId": 46
    }
  ],
  "query": "federal reserve",
  "total": null,
  "dataset": "sources",
  "hasMore": false,
  "nextPage": null,
  "provider": "fred"
}
```

---

### Tags

The tag vocabulary FRED indexes its catalogue with — geography, frequency,

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/tags`
- **Cache TTL:** 86400s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `page` | number | query | no | Tag page, ~50 tags each, most-used first (default 1) |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/tags?page=1" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/tags?page=1", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/tags?page=1",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "page": 1,
  "count": 50,
  "items": [
    {
      "tag": "nsa",
      "name": "Not Seasonally Adjusted",
      "seriesCount": 670000,
      "seriesCountApproximate": true
    },
    {
      "tag": "usa",
      "name": "United States of America",
      "seriesCount": 600000,
      "seriesCountApproximate": true
    },
    {
      "tag": "public domain: citation requested",
      "name": "Public Domain: Citation Requested",
      "seriesCount": 550000,
      "seriesCountApproximate": true
    },
    {
      "tag": "annual",
      "name": "Annual",
      "seriesCount": 440000,
      "seriesCountApproximate": true
    },
    {
      "tag": "county",
      "name": "County or County Equivalent",
      "seriesCount": 290000,
      "seriesCountApproximate": true
    },
    {
      "tag": "nation",
      "name": "Nation",
      "seriesCount": 250000,
      "seriesCountApproximate": true
    }
  ],
  "total": null,
  "dataset": "tags",
  "hasMore": true,
  "nextPage": 2,
  "provider": "fred"
}
```

---

### Vintage Dates

Every vintage ALFRED holds for one series — the dates on which that series was

- **Method:** `GET`
- **Endpoint:** `https://api.zpi.web.id/v1/finance:fred/vintage-dates`
- **Cache TTL:** 21600s

**Parameters:**

| Name | Type | Location | Required | Description |
|------|------|----------|----------|-------------|
| `series` | string | query | no | One FRED/ALFRED series id. Case-insensitive. Default GDP. |
| `length` | number | query | no | Vintage dates to return, newest first (default 50, max 2000) |

**cURL:**
```bash
curl "https://api.zpi.web.id/v1/finance:fred/vintage-dates?series=GDP&length=50" \
  -H "x-api-key: YOUR_API_KEY"
```

**JavaScript / TypeScript:**
```javascript
const res = await fetch("https://api.zpi.web.id/v1/finance:fred/vintage-dates?series=GDP&length=50", {
  headers: { "x-api-key": process.env.ZAPI_KEY }
});
const data = await res.json();
```

**Python:**
```python
import requests
r = requests.get("https://api.zpi.web.id/v1/finance:fred/vintage-dates?series=GDP&length=50",
  headers={"x-api-key": "YOUR_API_KEY"})
data = r.json()
```

**Example response:**
```json
{
  "count": 50,
  "items": [
    "2026-07-30",
    "2026-06-25",
    "2026-05-28",
    "2026-04-30",
    "2026-04-09",
    "2026-03-13"
  ],
  "total": 413,
  "series": "GDP",
  "dataset": "vintage-dates",
  "provider": "fred",
  "firstVintage": "1991-12-04",
  "latestVintage": "2026-07-30"
}
```

---


_Generated: 2026-08-20T22:23:50.879Z_