# io.github.cyanheads/exchange-rates-mcp-server (remote · exchange-rates.caseyjhand.com)

Convert currencies, get FX rates, and query historical ECB exchange rate data.

- Trust score: 72/100 (medium)
- Change this week: +3
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-08-03

## Components

- remote · `exchange-rates.caseyjhand.com`: 72/100 (this document), [markdown](https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/exchange-rates.md), [page](https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/exchange-rates)
- npm · `@cyanheads/exchange-rates-mcp-server`: 34/100, [markdown](https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/cyanheads-exchange-rates-mcp-server.md), [page](https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/cyanheads-exchange-rates-mcp-server)

## Channel facts

- Endpoint: `https://exchange-rates.caseyjhand.com/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.2.1`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-08-03.

- **Endpoint Security**: 66/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not fully verified: no authorisation is required to call this server, and 7 tool(s) never declared a destructiveHint. The MCP spec treats an absent hint as destructive by default, so we cannot call this surface safe.
  - HTTPS is enforced; there's no plaintext access path.
  - The HSTS (Strict-Transport-Security) header is present.
  - DNSSEC is configured correctly; the domain's records validate against the full chain to the root.
- **Transport & Reachability**: 100/100
  - Verified streamable-http transport via a live MCP handshake.
- **Schema Quality & AI Usability**: 84/100
  - 100% of prompts and resources have a non-trivial description (not blank, and not just the item's name).
  - AI-judged instruction clarity (excellent).
  - Context-footprint check failed: tool/resource definitions use about 1634 tokens (~136/item across 12 items; 7 tools + 5 resources), over budget; trim descriptions and params.
  - Usage-examples check failed: none of the tools include examples.
- **Stability & Change Management**: 27/100
  - Stability observed for 8 of 30 days with no destabilising changes; credit accrues until the full window elapses.
- **Tool Coverage**: 100/100
  - 100% of tools have a non-trivial description (not blank, and not just the tool's name).
  - 100% of tool parameters carry a description.
  - Structured output schemas are declared (100% of tools); any adoption earns full credit.
- **Capabilities**: 100/100
  - Implements a supported MCP spec version (2025-11-25); the latest is 2026-07-28.

## Install

### Claude

```bash
claude mcp add --transport http cyanheads-exchange-rates-mcp-server https://exchange-rates.caseyjhand.com/mcp
```

### Codex

```toml
[mcp_servers.cyanheads-exchange-rates-mcp-server]
url = "https://exchange-rates.caseyjhand.com/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "cyanheads-exchange-rates-mcp-server": {
      "type": "remote",
      "url": "https://exchange-rates.caseyjhand.com/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add cyanheads-exchange-rates-mcp-server --url https://exchange-rates.caseyjhand.com/mcp --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  cyanheads-exchange-rates-mcp-server:
    url: "https://exchange-rates.caseyjhand.com/mcp"
```

### Other

```json
{
  "mcpServers": {
    "cyanheads-exchange-rates-mcp-server": {
      "type": "http",
      "url": "https://exchange-rates.caseyjhand.com/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-08-02 (score 72, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-31 (score 71, 0)

- [security] The server rewrote its instructions, which are the text every model session reads
- [security] Tool “fx_get_rates” rewrote its description, which is the text the model reads
- [security] Tool “fx_get_timeseries” rewrote its description, which is the text the model reads
- [security] Tool “fx_dataframe_query” rewrote its description, which is the text the model reads
- [security] Tool “fx_get_rate” rewrote its description, which is the text the model reads
- [security] Tool “fx_dataframe_describe” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 116 → 136
- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server
- [functional] Server version: 0.1.5 → 0.2.1
- [cosmetic] “fx_get_rates” reworded the description of “symbols”
- [cosmetic] “fx_convert_currency” reworded the description of “amount”

### 2026-07-30 (score 71, +1)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-28 (score 70, +1)

No change was recorded against any check on this day. Stability & Change Management went from 3 to 7. That category is still filling its 30-day observation window: 1 days of observed history at the previous scan, 2 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-07-27 (score 69, +1)

- [functional] We updated how we score, so this day's move reflects our rubric, not a change to the server

### 2026-07-26 (score 68)

First indexed and scored.

## MCP tools (7)

### `fx_list_currencies` (~67 tokens)

Fx List Currencies

List all supported ISO 4217 currency codes with their full names. Call this before converting to disambiguate "dollars" (USD vs AUD vs CAD vs HKD vs SGD) or to validate a user-supplied currency code. Covers the ~30 ECB reference currencies.

Output parameters:

- `count` (number): Total number of supported currencies.
- `currencies` (array): All supported currencies, sorted alphabetically by code.
- `source` (string): Always "ECB via Frankfurter" — the upstream data provider.

### `fx_get_rates` (~199 tokens)

Fx Get Rates

Get all available exchange rates for one base currency in a single snapshot. Useful for bulk comparison and seeding downstream tools. Returns a map of quote currency → rate plus the snapshot date. Optionally filter to a subset of quote currencies via symbols. Listing the base currency itself in symbols is accepted and returns a rate of 1 for it.

Input parameters:

- `base_currency` (string, required): ISO 4217 base currency code (e.g. USD). Call fx_list_currencies to get valid codes.
- `date` (string): ISO 8601 date (YYYY-MM-DD). Omit for the latest available rate. ECB data starts 1999-01-04. Future dates are not supported.
- `symbols` (array): Optional list of quote currency codes to filter the response. Omit to return all ~30 supported currencies (the base is not among them). Including base_currency here is valid — it comes back with a ra…

Output parameters:

- `base_currency` (string): The base currency code.
- `rate_date` (string): Actual date of the rates. May differ from requested date on weekends/holidays — ECB publishes business days only; the API silently snaps to the prior business day.
- `rate_type` (string): Always "ECB reference (mid-market)" — these are reference rates, not tradeable bid/ask.
- `rates` (object): Map of quote currency code → exchange rate (units of quote per 1 base).
- `source` (string): Always "ECB via Frankfurter" — the upstream data provider.

### `fx_get_rate` (~224 tokens)

Fx Get Rate

Get the exchange rate for a currency pair on a given date (default: latest). Returns the rate, the actual rate date (which may differ from the requested date on weekends/holidays — ECB publishes business days only), and source provenance. Cross-rates are triangulated through EUR automatically. A same-currency pair returns a rate of 1, dated to the same publication day any other pair would report for that date. Use fx_convert_currency when you want the converted amount; use this tool when you only need the rate number.

Input parameters:

- `base_currency` (string, required): ISO 4217 base currency code (e.g. USD). Call fx_list_currencies to get valid codes.
- `date` (string): ISO 8601 date (YYYY-MM-DD). Omit for the latest available rate. ECB data starts 1999-01-04. Future dates are not supported.
- `quote_currency` (string, required): ISO 4217 quote currency code (e.g. EUR). The rate is expressed as "how many quote units per 1 base unit".

Output parameters:

- `base_currency` (string): The base currency code.
- `date_snapped` (boolean): True when the API returned a different date than requested — ECB silently snaps weekend/holiday requests to the prior business day.
- `quote_currency` (string): The quote currency code.
- `rate` (number): Exchange rate: units of quote currency per 1 unit of base currency.
- `rate_date` (string): Actual date of the rate returned.
- `rate_type` (string): Always "ECB reference (mid-market)" — these are reference rates, not tradeable bid/ask.
- `source` (string): Always "ECB via Frankfurter" — the upstream data provider.

### `fx_convert_currency` (~190 tokens)

Fx Convert Currency

Convert an amount between any two currencies at the latest or a historical rate. Returns the converted amount, the rate used, the actual rate date, and whether the date was snapped from a weekend/holiday to the prior business day. Cross-rates are triangulated through EUR automatically.

Input parameters:

- `amount` (number, required): Amount in the base currency to convert. Must be greater than zero.
- `base_currency` (string, required): ISO 4217 source currency code (e.g. USD). Call fx_list_currencies to get valid codes.
- `date` (string): ISO 8601 date (YYYY-MM-DD) for a historical rate. Omit for the latest available rate. ECB data starts 1999-01-04. Future dates are not supported.
- `quote_currency` (string, required): ISO 4217 target currency code (e.g. EUR). The amount will be expressed in this currency.

Output parameters:

- `base_amount` (number): The input amount in the base currency.
- `base_currency` (string): Source currency code.
- `date_snapped` (boolean): True when the API returned a different date than requested — ECB silently snaps weekend/holiday requests to the prior business day.
- `quote_amount` (number): The converted amount in the quote currency, rounded to 6 decimal places.
- `quote_currency` (string): Target currency code.
- `rate` (number): Exchange rate used: units of quote currency per 1 unit of base currency.
- `rate_date` (string): Actual date of the rate used for conversion.
- `rate_type` (string): Always "ECB reference (mid-market)" — these are reference rates, not tradeable bid/ask.
- `source` (string): Always "ECB via Frankfurter" — the upstream data provider.

### `fx_get_timeseries` (~360 tokens)

Fx Get Timeseries

Get historical daily exchange rates for a currency pair over a date range. ECB publishes on business days only — weekends and holidays produce no entry, and no date outside the requested range is ever returned, so a range covering only non-publication days comes back with an empty rates map and a notice explaining why. A same-currency pair returns a rate of 1 on each publication day in the range. Short ranges (≤90 days by default) are returned inline as a date→rate map. When DataCanvas is enabled (CANVAS_PROVIDER_TYPE=duckdb) long ranges spill to it: the response carries spilled=true, a canvas_id, and a table_name — call fx_dataframe_describe to inspect the staged table, then fx_dataframe_query to run SQL against it. Without DataCanvas long ranges stay inline (spilled=false) and the notice says so.

Input parameters:

- `base_currency` (string, required): ISO 4217 base currency code (e.g. USD). Call fx_list_currencies to get valid codes.
- `canvas_id` (string): Optional canvas ID from a prior call. Omit on the first call to start a fresh canvas; pass the returned canvas_id to append tables to an existing canvas.
- `end_date` (string, required): ISO 8601 end date (YYYY-MM-DD). Must be >= start_date. Future dates are not supported.
- `quote_currency` (string, required): ISO 4217 quote currency code (e.g. EUR). Call fx_list_currencies to get valid codes.
- `start_date` (string, required): ISO 8601 start date (YYYY-MM-DD). ECB data starts 1999-01-04. The actual first data point may be later if start_date falls on a weekend/holiday.

Output parameters:

- `base_currency` (string): Base currency code.
- `canvas_id` (string): Canvas ID — present when spilled is true. Pass to fx_dataframe_query.
- `end_date` (string): Last date in the returned series. Always inside the requested range — earlier than the requested end when that day had no ECB fix, and equal to it when the series is empty.
- `notice` (string): Explains a result that would otherwise look broken — an empty series, or a long range that stayed inline because DataCanvas is not configured.
- `quote_currency` (string): Quote currency code.
- `rate_count` (number): Total number of data points (publication days) inside the requested range.
- `rate_type` (string): Always "ECB reference (mid-market)" — these are reference rates, not tradeable bid/ask.
- `rates` (object): Date → rate map for the inline result. Publication days inside the requested range only. Truncated to a preview when the result was spilled to canvas; empty when the range contains no publication day…
- `source` (string): Always "ECB via Frankfurter" — the upstream data provider.
- `spilled` (boolean): True when the full result was staged on the DataCanvas (range exceeded threshold).
- `start_date` (string): First date in the returned series. Always inside the requested range — later than the requested start when that day had no ECB fix, and equal to it when the series is empty.
- `table_name` (string): Canvas table name — present when spilled is true. Use in fx_dataframe_query SQL.

### `fx_dataframe_describe` (~112 tokens)

Fx Dataframe Describe

List tables and columns staged on a DataCanvas from a prior fx_get_timeseries call. Required first step before fx_dataframe_query — use it to discover table names and column schemas. Requires DataCanvas (CANVAS_PROVIDER_TYPE=duckdb) — without it this tool is not listed at all and fx_get_timeseries returns every range inline.

Input parameters:

- `canvas_id` (string, required): Canvas ID returned by fx_get_timeseries. Re-run fx_get_timeseries to obtain a fresh canvas_id if this one has expired.

Output parameters:

- `canvas_id` (string): The canvas ID echoed back — use this in fx_dataframe_query.
- `expires_at` (string): ISO 8601 timestamp when this canvas will be evicted.
- `tables` (array): All tables and views currently staged on this canvas.

### `fx_dataframe_query` (~185 tokens)

Fx Dataframe Query

Run a read-only SQL SELECT against DataCanvas tables staged by fx_get_timeseries. Supports aggregations, GROUP BY, window functions, and JOINs across multiple registered tables. Run fx_dataframe_describe first to discover table names and column schemas. Requires DataCanvas (CANVAS_PROVIDER_TYPE=duckdb) — without it this tool is not listed at all and fx_get_timeseries returns every range inline.

Input parameters:

- `canvas_id` (string, required): Canvas ID returned by fx_get_timeseries. Re-run fx_get_timeseries to obtain a fresh canvas_id if this one has expired.
- `query` (string, required): Read-only SQL SELECT statement. Reference tables by the names returned by fx_dataframe_describe or the table_name field from fx_get_timeseries. Example: SELECT date, rate FROM fx_usd_eur WHERE date >…

Output parameters:

- `canvas_id` (string): The canvas ID used — pass to a subsequent fx_dataframe_query or fx_dataframe_describe call.
- `row_count` (number): Rows returned. Equals the materialized row count; when truncated is true this is the row cap, not the full result size. Narrow the SELECT (add WHERE/LIMIT or aggregate) to see all rows.
- `rows` (array): Result rows, capped at the canvas row limit (default 10 000). Each key is a column name from the query.
- `truncated` (boolean): True when the query produced more rows than the canvas row cap and the result was capped. Refine the query to materialize the complete result.

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/exchange-rates#diagnostics

## Score history

- 2026-08-03: 72
- 2026-08-02: 72
- 2026-08-01: 71
- 2026-07-31: 71
- 2026-07-30: 71
- 2026-07-29: 70
- 2026-07-28: 70
- 2026-07-27: 69
- 2026-07-26: 68

## Links

- Remote endpoint: https://exchange-rates.caseyjhand.com/mcp
- Repository: https://github.com/cyanheads/exchange-rates-mcp-server
- Changelog RSS feed: https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/exchange-rates/changelog.xml
- Changelog JSON feed: https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/exchange-rates/changelog.json
- HTML version of this page: https://verifymcp.io/servers/cyanheads-exchange-rates-mcp-server/exchange-rates