# exchange-rates-mcp-server [Health: Active]
**Category:** π» Developer Tools
**Repository:** https://github.com/cyanheads/exchange-rates-mcp-server
**GitHub Stars:** 1
**Views:** 0
**Installs:** 0
**Upvotes:** 0
**Directory Page:** https://allmcps.com/mcp/exchange-rates-mcp-server
## Description
Convert currencies, get FX rates, and query historical ECB exchange rate data.
## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `bunx` (confidence: high):
```json
"mcpServers": {
"exchange-rates-mcp-server": {
"command": "bunx",
"args": ["@cyanheads/exchange-rates-mcp-server@latest"]
}
}
```
## Documentation & README
@cyanheads/exchange-rates-mcp-server
Convert currencies, get FX rates, and query historical ECB exchange rate data via MCP. STDIO or Streamable HTTP.
7 Tools β’ 1 Opt-in Tool β’ 2 Resources
[](./CHANGELOG.md) [](./LICENSE) [](https://github.com/users/cyanheads/packages/container/package/exchange-rates-mcp-server) [](https://modelcontextprotocol.io/) [](https://www.npmjs.com/package/@cyanheads/exchange-rates-mcp-server) [](https://www.typescriptlang.org/) [](https://bun.sh/)
[](https://github.com/cyanheads/exchange-rates-mcp-server/releases/latest/download/exchange-rates-mcp-server.mcpb) [](https://cursor.com/en/install-mcp?name=exchange-rates-mcp-server&config=eyJjb21tYW5kIjoibnB4IiwiYXJncyI6WyIteSIsIkBjeWFuaGVhZHMvZXhjaGFuZ2UtcmF0ZXMtbWNwLXNlcnZlciJdfQ==) [](https://vscode.dev/redirect?url=vscode:mcp/install?%7B%22name%22%3A%22exchange-rates-mcp-server%22%2C%22command%22%3A%22npx%22%2C%22args%22%3A%5B%22-y%22%2C%22%40cyanheads%2Fexchange-rates-mcp-server%22%5D%7D)
[](https://www.npmjs.com/package/@cyanheads/mcp-ts-core)
**Public Hosted Server:** [https://exchange-rates.caseyjhand.com/mcp](https://exchange-rates.caseyjhand.com/mcp)
---
## Tools
Eight tools for working with ECB FX rate data β currency lookup and disambiguation, point-in-time rates and conversions, historical time-series retrieval, and SQL analytics over the DataCanvas workspace that long time-series calls produce. Five are advertised by default; the three `fx_dataframe_*` tools need `CANVAS_PROVIDER_TYPE=duckdb`, and the destructive one among them additionally needs `FX_ENABLE_CANVAS_DROP=true`.
The three `fx_dataframe_*` tools require DataCanvas. With `CANVAS_PROVIDER_TYPE` unset (the default) they are not advertised in `tools/list` at all, so a client never sees a tool it cannot call; the HTTP landing page still lists them as disabled cards hinting `CANVAS_PROVIDER_TYPE=duckdb`, so operators can tell they exist. In that mode `fx_get_timeseries` returns every range inline:
| Tool | Description |
|:-----|:------------|
| `fx_list_currencies` | List all ~30 ECB-supported ISO 4217 currencies with full names. Use before converting to disambiguate "dollars" (USD vs AUD vs CAD vs HKD vs SGD). |
| `fx_get_rates` | Snapshot of all available rates for a base currency at latest or a historical date. Optional `symbols` filter for smaller responses; listing the base itself returns a rate of 1 for it. |
| `fx_get_rate` | Exchange rate for a single currency pair at latest or a historical date. Surfaces `date_snapped` when a weekend/holiday request returns the prior business-day rate. |
| `fx_convert_currency` | Convert an amount between any two currencies at latest or a historical rate. Cross-rates are triangulated through EUR. Returns converted amount, rate used, rate date, and whether the date was snapped. |
| `fx_get_timeseries` | Historical daily rates for a currency pair over a date range, never including a date outside it. Short ranges (β€90 days) are returned inline; when DataCanvas is enabled, long ranges spill to it with a `canvas_id` for SQL follow-up. |
| `fx_dataframe_describe` | List DataCanvas tables and their columns from a prior `fx_get_timeseries` call. Required first step before `fx_dataframe_query`. Needs `CANVAS_PROVIDER_TYPE=duckdb`. |
| `fx_dataframe_query` | Run a read-only SQL SELECT against a DataCanvas table produced by `fx_get_timeseries`. Supports aggregations, GROUP BY, window functions, and JOINs across multiple registered tables. Needs `CANVAS_PROVIDER_TYPE=duckdb`. |
| `fx_dataframe_drop` | Permanently remove one staged table or view from a DataCanvas. Deletes staged analytical data only β ECB rate data is untouched and the series can be re-staged. Needs `CANVAS_PROVIDER_TYPE=duckdb` and `FX_ENABLE_CANVAS_DROP=true`; disabled otherwise. |
### `fx_list_currencies`
Enumerate all supported currencies before converting or querying.
- Returns `[{ code, name }]` for all ~30 ECB-scoped currencies
- ECB coverage fluctuates as currencies enter/exit scope β always call this tool to validate user-supplied codes rather than hard-coding a list
---
### `fx_get_rates`
Full rates snapshot for a base currency in one call.
- Returns all available quote currencies at a given date (default: latest)
- Optional `symbols` parameter narrows the response to specific quote currencies
- Naming the base currency in `symbols` is valid β it is answered locally with a rate of 1 rather than sent upstream, which keeps a self-quote from failing
- Useful for seeding bulk comparison workflows or discovering what's available
---
### `fx_get_rate`
Point-in-time exchange rate for a single pair.
- Returns the rate, the actual rate date, and `date_snapped: true` when the API silently moved a weekend/holiday request to the prior business day
- Cross-rates (neither side EUR) are triangulated in a single API call β no extra round trip
- A same-currency pair returns a rate of 1 without a self-quote reaching the API, but still reports the publication date the ECB actually had for that currency, so `rate_date` and `date_snapped` read the same as for any other pair
- Use `fx_convert_currency` when you need the converted amount; use this tool when you only need the rate number
---
### `fx_convert_currency`
Convert an amount between any two currencies.
- Handles EUR β any, any β EUR, and cross-rate (USD β JPY via EUR) in one upstream call
- Returns `quote_amount`, `rate`, `rate_date`, `date_snapped`, plus `rate_type` and `source` provenance on every response
- Historical conversions supported back to 1999-01-04 (ECB launch date)
---
### `fx_get_timeseries` + `fx_dataframe_describe` / `fx_dataframe_query`
Historical rate series and DataCanvas SQL analytics.
`fx_get_timeseries` returns a date-keyed series (business days only β ECB publishes once per business day):
- Short ranges (β€ `FX_TIMESERIES_CANVAS_THRESHOLD_DAYS`, default 90 days) β inline `rates` map + metadata
- Long ranges, **when DataCanvas is enabled** β first N rows inline + `canvas_id`, `table_name`, and `spilled: true` β the full series is registered as a DuckDB-backed table. Without `CANVAS_PROVIDER_TYPE=duckdb` a long range comes back inline with `spilled: false` and a `notice` saying the threshold was crossed but no canvas was configured
- Requesting the same currency on both sides returns a rate of 1 on each publication day in the range, taken from the ECB's real calendar rather than a synthetic MonβFri loop
The response never carries a date outside the requested range. Frankfurter snaps a range that opens on a weekend or bank holiday back to the prior publication day; those rows are dropped, so `start_date` and `end_date` always sit inside the window you asked for. A range covering only non-publication days therefore returns an empty `rates` map with `rate_count: 0` and a `notice` explaining that the ECB published nothing in that window β distinguishable from an error.
Once a `canvas_id` is in hand:
1. **`fx_dataframe_describe`** β list the tables and columns on the canvas (required before `fx_dataframe_query`)
2. **`fx_dataframe_query`** β run arbitrary SQL SELECT against the registered table; supports aggregations, GROUP BY, window functions, JOINs across tables from multiple `fx_get_timeseries` calls
The canvas uses a session-scoped TTL. To continue working with a prior series, call `fx_get_timeseries` again with the same parameters to obtain a fresh `canvas_id`.
---
## Resources and prompts
| Type | Name | Description |
|:-----|:-----|:------------|
| Resource | `fx://currencies` | All supported currencies as a stable reference document. Injectable context for clients that support resources. |
| Resource | `fx://rates/latest/{base}` | Latest rates snapshot for a base currency as a stable URI. |
All resource data is also reachable via tools. Use `fx_list_currencies` or `fx_get_rates` for programmatic access.
---
## Features
Built on [`@cyanheads/mcp-ts-core`](https://www.npmjs.com/package/@cyanheads/mcp-ts-core):
- Declarative tool and resource definitions β single file per primitive, framework handles registration and validation
- Unified error handling β handlers throw, framework catches, classifies, and formats
- Typed error contracts with recovery hints β `unsupported_currency`, `date_out_of_range`, `canvas_not_found`, `missing_table`, `invalid_query`
- Pluggable auth: `none`, `jwt`, `oauth`
- Structured logging with optional OpenTelemetry tracing
- STDIO and Streamable HTTP transports
ECB FXβspecific:
- Keyless access via [Frankfurter](https://www.frankfurter.dev/) β a Cloudflare-fronted ECB proxy; no API keys required
- Cross-rate triangulation: any pair works β USD β JPY is one upstream call, cross-rated through EUR on Frankfurter's side
- Weekend/holiday date semantics: `date_snapped` flag surfaces when the API returns a different date than requested
- ECB data covers ~30 major currencies from 1999-01-04 to present; `fx_list_currencies` always reflects the live set
- Identity pairs never surface an upstream rejection: `fx_get_rate`, `fx_get_rates`, and `fx_get_timeseries` all return a rate of 1 for a currency against itself, dated to the days the ECB actually published for that currency rather than to the calendar dates requested
- DataCanvas integration: when enabled, `fx_get_timeseries` spills long ranges to DuckDB for aggregations and trend analysis
- Rate provenance on every response: `rate_type: "ECB reference (mid-market)"` and `source: "ECB via Frankfurter"` β explicitly mid-market, not tradeable bid/ask
Agent-friendly output:
- Rate provenance on every response β `rate_type`, `source`, `rate_date`, and `date_snapped` so agents can reason about trust and freshness
- Structured error contracts β typed `reason` fields (`unsupported_currency`, `date_out_of_range`, `invalid_query`, β¦) let callers branch on failure type, not string parsing
- Discriminated DataCanvas output β `spilled: true` plus `canvas_id` signal when a time-series was staged for SQL follow-up rather than returned inline
- Success-path `notice` enrichment β explains an empty series or a long range that stayed inline, so a legitimate zero-result never reads as a failure
---
## Getting started
### Public Hosted Instance
A public instance is available at `https://exchange-rates.caseyjhand.com/mcp` β no installation required. Point any MCP client at it via Streamable HTTP:
```json
{
"mcpServers": {
"exchange-rates-mcp-server": {
"type": "streamable-http",
"url": "https://exchange-rates.caseyjhand.com/mcp"
}
}
}
```
### Self-Hosted / Local
No API key required β Frankfurter is keyless. Add the following to your MCP client configuration file:
```json
{
"mcpServers": {
"exchange-rates-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/exchange-rates-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with npx (no Bun required):
```json
{
"mcpServers": {
"exchange-rates-mcp-server": {
"type": "stdio",
"command": "npx",
"args": ["-y", "@cyanheads/exchange-rates-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"MCP_LOG_LEVEL": "info"
}
}
}
}
```
Or with Docker:
```json
{
"mcpServers": {
"exchange-rates-mcp-server": {
"type": "stdio",
"command": "docker",
"args": [
"run", "-i", "--rm",
"-e", "MCP_TRANSPORT_TYPE=stdio",
"ghcr.io/cyanheads/exchange-rates-mcp-server:latest"
]
}
}
}
```
To enable DataCanvas for long time-series SQL analytics β which also registers `fx_dataframe_describe` and `fx_dataframe_query`, skipped from `tools/list` otherwise β add `CANVAS_PROVIDER_TYPE=duckdb`:
```json
{
"mcpServers": {
"exchange-rates-mcp-server": {
"type": "stdio",
"command": "bunx",
"args": ["@cyanheads/exchange-rates-mcp-server@latest"],
"env": {
"MCP_TRANSPORT_TYPE": "stdio",
"CANVAS_PROVIDER_TYPE": "duckdb"
}
}
}
}
```
For Streamable HTTP, set the transport and start the server:
```sh
MCP_TRANSPORT_TYPE=http MCP_HTTP_PORT=3010 bun run start:http
# Server listens at http://localhost:3010/mcp
```
### Prerequisites
- [Bun v1.3.0](https://bun.sh/) or higher (or Node.js v24+).
- No API key β Frankfurter is free and keyless.
### Installation
1. **Clone the repository:**
```sh
git clone https://github.com/cyanheads/exchange-rates-mcp-server.git
```
2. **Navigate into the directory:**
```sh
cd exchange-rates-mcp-server
```
3. **Install dependencies:**
```sh
bun install
```
4. **Configure environment:**
```sh
cp .env.example .env
# edit .env as needed (all vars are optional β no keys required)
```
---
## Configuration
All configuration is validated at startup via Zod schemas. Environment variables:
| Variable | Description | Default |
|:---------|:------------|:--------|
| `FRANKFURTER_BASE_URL` | Frankfurter API base URL. Override for local testing or a self-hosted instance. | `https://api.frankfurter.dev/v1` |
| `FX_TIMESERIES_CANVAS_THRESHOLD_DAYS` | Day range above which `fx_get_timeseries` spills to DataCanvas, when one is configured. | `90` |
| `FX_ENABLE_CANVAS_DROP` | Enable the destructive `fx_dataframe_drop` tool. Off by default: the tool stays listed with its enable hint but is uncallable. | `false` |
| `CANVAS_PROVIDER_TYPE` | Canvas engine. Set to `duckdb` to enable DataCanvas for `fx_get_timeseries` long-range spillover and to register the three `fx_dataframe_*` tools. At `none` they are skipped from `tools/list`. | `none` |
| `MCP_TRANSPORT_TYPE` | Transport: `stdio` or `http`. | `stdio` |
| `MCP_HTTP_PORT` | Port for HTTP server. | `3010` |
| `MCP_SESSION_MODE` | HTTP session mode: `auto`, `stateful`, or `stateless`. `.env.example` and the Dockerfile both set `stateless` β no handler here asks the client for input mid-call, so nothing needs a session to resume. | `auto` (resolves to `stateful`) |
| `MCP_AUTH_MODE` | Auth mode: `none`, `jwt`, or `oauth`. | `none` |
| `MCP_LOG_LEVEL` | Log level (RFC 5424: `debug`, `info`, `notice`, `warning`, `error`). | `info` |
| `OTEL_ENABLED` | Enable [OpenTelemetry instrumentation](https://github.com/cyanheads/mcp-ts-core/tree/main/docs/telemetry). | `false` |
See [`.env.example`](https://github.com/cyanheads/exchange-rates-mcp-server/blob/HEAD/.env.example) for the full list of optional overrides including storage, session, and telemetry vars.
---
## Running the server
### Local development
- **Build and run:**
```sh
bun run rebuild
bun run start:stdio
# or
bun run start:http
```
- **Run checks and tests:**
```sh
bun run devcheck # Lint, format, typecheck, security, changelog sync
bun run test # Vitest test suite
bun run lint:mcp # Validate MCP definitions against spec
```
### Docker
```sh
docker build -t exchange-rates-mcp-server .
docker run --rm -p 3010:3010 exchange-rates-mcp-server
```
The Dockerfile defaults to HTTP transport, stateless session mode, and logs to `/var/log/exchange-rates-mcp-server`. OpenTelemetry peer dependencies are installed by default β build with `--build-arg OTEL_ENABLED=false` to omit them. DuckDB native binaries are pre-built in the build stage and copied to production, keeping the production image free of build tools.
---
## Project structure
| Directory | Purpose |
|:----------|:--------|
| `src/index.ts` | `createApp()` entry point β registers tools, resources, and canvas accessor. |
| `src/config/` | Server-specific environment variable parsing and validation with Zod. |
| `src/mcp-server/tools/` | Tool definitions (`*.tool.ts`) β `fx_*` tools. |
| `src/mcp-server/resources/` | Resource definitions β `fx://currencies` and `fx://rates/latest/{base}`. |
| `src/services/frankfurter/` | Frankfurter HTTP client, retry logic, and domain types. |
| `src/services/canvas/` | Module-level DataCanvas accessor for `fx_get_timeseries` spillover. |
| `tests/` | Unit and integration tests mirroring `src/`. |
| `docs/` | Design document and idea notes. |
---
## Development guide
See [`CLAUDE.md`](https://github.com/cyanheads/exchange-rates-mcp-server/blob/HEAD/CLAUDE.md) for development guidelines and architectural rules. The short version:
- Handlers throw, framework catches β no `try/catch` in tool logic
- Use `ctx.log` for request-scoped logging, `ctx.state` for tenant-scoped storage
- Register new tools and resources via the barrels in `src/mcp-server/*/definitions/index.ts`
- Wrap external API calls: validate raw β normalize to domain type β return output schema; never fabricate missing fields
- ECB rates are mid-market reference rates β preserve the `rate_type` provenance in every response
---
## Contributing
Issues and pull requests are welcome. Run checks and tests before submitting:
```sh
bun run devcheck
bun run test
```
---
## License
Apache-2.0 β see [LICENSE](https://github.com/cyanheads/exchange-rates-mcp-server/blob/HEAD/LICENSE) for details.