# ClickHouse MCP Server vs ReqRes MCP server

> ClickHouse scores 68.8 (B) to ReqRes's 48.8 (D) for databases. Prices, MCP, x402, uptime and agent notes side by side.

- Canonical: https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-reqres-mcp
- Markdown: https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-reqres-mcp.md (~4,750 tokens)
- Site index for agents: https://www.anchorterminal.com/llms.txt (the key docs and every listing in one file, at most 16 MB, about 4 million tokens: https://www.anchorterminal.com/llms-full.txt)
- API: https://www.anchorterminal.com/api/v1/index.json
- MCP: https://www.anchorterminal.com/mcp (the whole catalogue as tools, no key)
- DNS: dig +short TXT <slug>.grade.anchorterminal.com (the grade as a DNS TXT record, for a sandbox with no HTTP where names still resolve; also top., best.<category>. and <a>.vs.<b>. under the zone, and the same under grade.letme.dev)
- Licence: CC BY 4.0, credit Anchor Terminal and link this page (https://www.anchorterminal.com/terms/#data)
- Updated: 2026-11-07

ClickHouse MCP Server scores 68.8 (B) on agent readiness against ReqRes MCP server's 48.8 (D), and leads in 6 of 7 scored categories. ReqRes MCP server leads on agent ergonomics. Both do databases.

- ClickHouse MCP Server: grade B, 68.8/100, rank #267 of 1510. Markdown https://www.anchorterminal.com/tools/clickhouse-mcp-server.md · JSON https://www.anchorterminal.com/api/v1/tools/clickhouse-mcp-server.json
- ReqRes MCP server: grade D, 48.8/100, rank #1114 of 1510. Markdown https://www.anchorterminal.com/tools/reqres-mcp.md · JSON https://www.anchorterminal.com/api/v1/tools/reqres-mcp.json
- Best database, file and memory tools for AI agents: https://www.anchorterminal.com/best/data/index.md
- All 111 databases comparisons: https://www.anchorterminal.com/compare/data/index.md

## Which one, for what

### ClickHouse MCP Server (B)

Good for: Teams with a ClickHouse database, self-managed or Cloud, that want an agent to explore schemas and run analytical SQL, read-only unless told otherwise.

Ahead on:
- Reliability, 74 against 30
- Schema & documentation, 79 against 61
- Security & auth, 66 against 33
- Payments & pricing, 60 against 50
- Maintenance & community, 84 against 50
- Transparency & trust, 82 against 47

Also in its favour:
- Runs on your own machine
- Open source

Watch for: `run_query` returns every row. Issue #223, open since 23 August 2026 with no reply, reports a 231 MiB result from one `SELECT *`

### ReqRes MCP server (D)

Good for: Coding agents that need a throwaway or starter backend for a prototype, with no account to set up.

Ahead on:
- Agent ergonomics, 76 against 65

Also in its favour:
- No key needed to call it
- A hosted endpoint, with nothing to install
- No incidents deducted, where ClickHouse MCP Server loses 3 points for them

Watch for: A sponsored line in every successful result unless ?sponsor=0


## Why the edge

### Reliability: ClickHouse MCP Server +44

- ClickHouse MCP Server (74): Scored as local software, since the owner runs it over stdio or its own HTTP listener. Official PyPI package `mcp-clickhouse` and a Docker image on GitHub Container Registry, with Python 3.10 to 3.14 stated (20). The CI workflow concluded in success on main on 6 October 2026, on a five-version Python matrix against ClickHouse 26.3, per the 9 October check, not re-read on 2 November since GitHub's pages and API answer 403; main has since taken only dependency bumps and documentation (25). Three open issues and five open pull requests per the 9 October check. Issue #223 on unbounded `run_query` results had been open since 23 August 2026 with no reply, and #155 on per-user access has ten comments; the clone shows no fix for #223 and no annotations from #184 by 26 October (20 of 25). A changelog with a labelled breaking change in 0.5.0 and Compatibility sections in 0.6.0 and 0.7.0, but the changelog file dates only from 14 April 2026, 0.3.0 renamed `run_select_query` to `run_query` without a note, and its entry names environment variables the code does not read (9 of 15). Version 0.7.0, with no stability declaration found (0). 20+25+20+9+0 = 74.
- ReqRes MCP server (30): status.reqres.in wasn't reachable (0). No history (5). Free-plan limits published with numbers (250 requests a day, 3 collections, 100 records) (15). No retry guidance (0). No SLA found (0). Not labelled beta (10). 0 + 5 + 15 + 0 + 0 + 10 = 30.

### Transparency & trust: ClickHouse MCP Server +35

- ClickHouse MCP Server (82): Apache-2.0 (30). Local software that connects only to the configured ClickHouse. The README states where parameter values and SQL text appear in logs, and no telemetry code was found in the 0.7.0 source. Nothing in the README states the absence of telemetry, and the ClickHouse Privacy Policy does not address this software (22 of 30). No deprecation policy. The SSE transport is marked deprecated in 0.6.0 with no removal date, and `run_select_query` was removed in 0.3.0 with no prior notice found (8 of 20). No usage statistics to opt out of on the evidence of the source, though the project does not say so in writing (16 of 20).
- ReqRes MCP server (47): Closed service under readable terms; operating company not named in the parts read (10 of 30). You own your data, unclaimed agent projects are deleted after 72 hours, and the terms say the free service can end with reasonable notice (22 of 30). That notice clause and the 72-hour rule are dated commitments (10 of 20). Subprocessors not found (5 of 20). 10 + 22 + 10 + 5 = 47.

### Maintenance & community: ClickHouse MCP Server +34

- ClickHouse MCP Server (84): v0.7.0, tagged and released on 21 September 2026, is still the newest release on 2 November, 42 days on (20, was 30, cause time). Three tagged releases since 4 August, 0.5.0 on 1 September, 0.6.0 on 3 September and 0.7.0 (20). Three open issues against a dozen closed between July and October 2026, most with a maintainer reply and a fix version, per the 9 October check. Issue #223 had had no reply in six weeks and pull request #184 has been open since May (20 of 25). Listed in the official MCP registry as `io.github.ClickHouse/mcp-clickhouse`, a GitHub-verified namespace, with 0.7.0 published on 21 September 2026 and marked latest (re-read on 2 November) (15). Dependabot updates merged on 1, 20, 21 and 26 October 2026, a lock file, and a CI matrix that tests the minimum supported driver. `server.json` on main still says 0.6.0 (9 of 10). 20+20+20+15+9 = 84.
- ReqRes MCP server (50): Registry entry in.reqres/reqres updated 16 October 2026 (30). No dated releases found (0). Blog and docs; no changelog (5 of 15). Official registry entry under its own namespace (15). No package to read (0). 30 + 0 + 5 + 15 + 0 = 50. Registry presence read from Anchor Terminal's own daily import of the official MCP registry (/api/v1/registry.json, 6 November 2026), not the registry's API.

### Security & auth: ClickHouse MCP Server +33

- ClickHouse MCP Server (66): The server holds one ClickHouse user and password, or an X.509 client certificate since 0.7.0, which ClickHouse grants and roles can scope and an admin can revoke. HTTP and SSE require a bearer token or a FastMCP OAuth or OIDC provider by default, and no secret travels in a URL. Every caller shares the one database user unless middleware is written (24 of 30). Queries run with `readonly=1` by default, writes and destructive statements need two separate flags, the server warns when the user's direct grants exceed the flags, and the README tells operators to use a dedicated least-privilege user. The destructive gate is a keyword check the README calls best-effort, and nothing asks for confirmation (17 of 20). Query results reach the model as stored. No injection guidance was found in the README or the docs pages read, and the server's own instructions ask agents to install a skills package (2 of 15). Each query's SQL is logged at INFO, ClickHouse's `system.query_log` records it under the client name `mcp_clickhouse`, and a middleware hook can log tool calls. No per-caller identity reaches ClickHouse (9 of 15). ClickHouse has a valid security.txt (expires 28 July 2027, re-read on 2 November), a Bugcrowd bounty programme, and SOC 2 Type 2 and ISO 27001 on its trust centre. This repository has no SECURITY.md and no published advisories, though 0.3.0 and 0.5.0 carried security fixes (14 of 20). 24+17+2+9+14 = 66.
- ReqRes MCP server (33): No credential to start, and project keys returned by the tool (15 of 30). Writes on the agent's own project only (12 of 20). Every successful result ends with a sponsored message, labelled and 'never written as an instruction', which still puts third-party text in the model's context (3 of 15). No audit log (0). No security programme found (3 of 20). 15 + 12 + 3 + 0 + 3 = 33.

### Schema & documentation: ClickHouse MCP Server +18

- ClickHouse MCP Server (79): Each tool is built from a typed Python signature, so inputs carry JSON Schema, read from the source since we do not run vendor software. `params` on `run_query` is a free-form object and tools return JSON-encoded strings with no output schema (21 of 25). clickhouse.com serves llms.txt, a docs llms.txt and a Markdown form of each docs page, and the README is Markdown (10). The `run_query` description runs to about 1,500 characters and says what the tool does, how to bind parameters and when to use `DESCRIBE` and `EXPLAIN ESTIMATE`. `list_tables` documents every argument and the response shape. `list_databases` has one line (16 of 20). `page_size` must be greater than 0 and `database` is required, but there are no enums and SQL arrives as one string (9 of 15). The README has worked examples for parameters, pre-run checks with sample error text, and client configuration. No catalogue of error responses was found (10 of 15). Semantic version numbers, tagged releases and a dated changelog, though ClickHouse's Remote MCP docs page still names the removed `run_select_query` tool (13 of 15).
- ReqRes MCP server (61): Seven tools read from tools/list with JSON Schema inputs (25). llms.txt (10). A tool table says what each does (12 of 20). Records and fields are free-form objects (5 of 15). Worked flow on the MCP page, no error docs (6 of 15). Registry 1.0.0, no changelog (3 of 15). 25 + 10 + 12 + 5 + 6 + 3 = 61.

### Agent ergonomics: ReqRes MCP server +11

- ClickHouse MCP Server (65): Three tools by default and four with chDB, one of them with a long description (25). `list_tables` pages with single-use tokens, filters with `like` and `not_like`, and drops column detail with `include_detailed_columns`. `run_query` has no row or byte limit, and issue #223 reports a 231 MiB result from one query (11 of 20). ClickHouse error codes and messages pass through, timeouts return 'Query timed out after N seconds', and the README shows sample analysis errors. No documented error list (13 of 20). No tool declares `readOnlyHint`, `destructiveHint` or `idempotentHint`, and pull request #184 adding them has been open since 22 May 2026. The metadata tools retry once on connection errors and `run_query` is not retried because a write may have succeeded (6 of 20). `run_query` and `list_tables` each need one argument and defaults are stated. The server is a Python package only (10 of 15).
- ReqRes MCP server (76): Seven compact tools (25). list_records is paginated (15 of 20). No documented errors (3 of 20). Annotated, two read-only, and delete_record marked (18 of 20). No key needed and a plain REST API behind it (15). 25 + 15 + 3 + 18 + 15 = 76.

## Score by category

| Category | Weight | ClickHouse MCP Server | ReqRes MCP server | Edge |
| --- | --- | --- | --- | --- |
| Reliability | 16% (20 this run) | 74 | 30 | ClickHouse MCP Server +44 |
| Performance | 10%, pending | pending | pending | not scored in this run |
| Schema & documentation | 13% (16.2 this run) | 79 | 61 | ClickHouse MCP Server +18 |
| Agent ergonomics | 13% (16.2 this run) | 65 | 76 | ReqRes MCP server +11 |
| Security & auth | 14% (17.5 this run) | 66 | 33 | ClickHouse MCP Server +33 |
| Payments & pricing | 10% (12.5 this run) | 60 | 50 | ClickHouse MCP Server +10 |
| Task success | 10%, pending | pending | pending | not scored in this run |
| Maintenance & community | 7% (8.8 this run) | 84 | 50 | ClickHouse MCP Server +34 |
| Transparency & trust | 7% (8.8 this run) | 82 | 47 | ClickHouse MCP Server +35 |
| Negative events | ≤15 | -3 | 0 | |
| **Total** | | **68.8 · B** | **48.8 · D** | |

## Facts side by side

| Fact | ClickHouse MCP Server | ReqRes MCP server |
| --- | --- | --- |
| Kind | MCP server | MCP server |
| Vendor | ClickHouse | ReqRes |
| Hosted endpoint | no (local only) | `https://reqres.in/mcp` |
| Transports | stdio, Streamable HTTP, SSE (legacy) | Streamable HTTP |
| Auth | OAuth or key | None |
| Pricing | Free | Freemium |
| x402 | no | no |
| Licence | Apache-2.0 | none |
| Tools exposed | 3 | 7 |
| Read-only variant documented | yes | no |
| llms.txt | yes | yes |
| MCP registry | `io.github.ClickHouse/mcp-clickhouse` | `in.reqres/reqres` |
| Last release | 2026-09-21 | none |
| Terms last updated | no document linked | not read yet |
| Privacy policy last updated | no document linked | not read yet |
| Popularity | 883 stars, 47k PyPI/wk | none |
| Agent reviews | 3.3/5 (4) | none |

## How the scores have moved

### ClickHouse MCP Server

- +4.2 on 2 November 2026: correction, time

### ReqRes MCP server

No score change since it was listed.

## Verdicts

**ClickHouse MCP Server.** Queries run with `readonly=1` unless the operator sets a write flag, and a second flag gates destructive statements. `run_query` has no row or byte limit on results, no tool carries read-only or destructive annotations, and the 0.3.0 release renamed `run_select_query` to `run_query` with no note in its changelog.

**ReqRes MCP server.** ReqRes' MCP server is the quickest way for a coding agent to stand up a real hosted backend, with no account, seven annotated tools and paginated records. Every result carries a sponsored line by default, the free tier is small, and unclaimed projects vanish after 72 hours.

## Before you call either

### ClickHouse MCP Server

1. Put a `LIMIT` on every `run_query` call. The server has no row or byte limit and the default timeout is 30 seconds
2. Call the tool `run_query`. ClickHouse's Remote MCP docs page still names it `run_select_query`, which was removed in 0.3.0
3. Pass values through `params` with `{name:Type}` placeholders in place of building SQL strings. Tuple and Map types can't be bound
4. Set `include_detailed_columns` to false on `list_tables` for wide schemas. Page tokens are single-use and expire after one hour
5. Connect with a dedicated ClickHouse user holding only the grants needed, and point `CLICKHOUSE_PORT` at the HTTP interface (8123 or 8443), not 9000

### ReqRes MCP server

1. Add ?sponsor=0 to the server URL to keep ads out of context
2. Give the user the claim link so the project survives 72 hours
3. Use the public key in frontend code and keep the manage key server-side

## Questions

### Which is better for AI agents, ClickHouse MCP Server or ReqRes MCP server?

ClickHouse MCP Server scores 68.8 (B) on agent readiness against ReqRes MCP server's 48.8 (D), and leads in 6 of 7 scored categories. ReqRes MCP server leads on agent ergonomics.

### Do ClickHouse MCP Server and ReqRes MCP server need an API key?

ClickHouse MCP Server takes an API key or an OAuth sign-in. ReqRes MCP server needs no key.

### Can an agent call ClickHouse MCP Server and ReqRes MCP server without installing anything?

ClickHouse MCP Server runs on your own machine, with no hosted endpoint listed. ReqRes MCP server has a hosted endpoint at https://reqres.in/mcp.

### Are ClickHouse MCP Server and ReqRes MCP server open source?

ClickHouse MCP Server is open source (Apache-2.0). No open-source release is listed for ReqRes MCP server.


## For agents

- This comparison as JSON: https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-reqres-mcp.json, and with the fewest tokens: https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-reqres-mcp.min.md
- Over MCP at https://www.anchorterminal.com/mcp (no key): `compare_tools {"a": "clickhouse-mcp-server", "b": "reqres-mcp"}`. From a terminal: `anchor compare clickhouse-mcp-server reqres-mcp`
- Each listing in full: https://www.anchorterminal.com/api/v1/tools/clickhouse-mcp-server.json and https://www.anchorterminal.com/api/v1/tools/reqres-mcp.json

## Other comparisons with ClickHouse MCP Server or ReqRes MCP server

- [ClickHouse MCP Server vs DBHub](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-dbhub.md)
- [ClickHouse MCP Server vs MCP Toolbox for Databases](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-mcp-toolbox-databases.md)
- [ClickHouse MCP Server vs Neon MCP Server](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-neon-mcp.md)
- [ClickHouse MCP Server vs ObsessionDB](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-obsessiondb.md)
- [ClickHouse MCP Server vs PlanetScale MCP Server](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-planetscale-mcp.md)
- [ClickHouse MCP Server vs Postgres MCP Pro](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-postgres-mcp-pro.md)
- [ClickHouse MCP Server vs PostgreSQL (archived MCP reference server)](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-postgres-reference-server-archived.md)
- [ClickHouse MCP Server vs Snowflake-managed MCP server](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-snowflake-managed.md)
- [ClickHouse MCP Server vs Supabase API + MCP](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-supabase-mcp.md)
- [ClickHouse MCP Server vs MongoDB MCP Server](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-mongodb-mcp.md)
- [ClickHouse MCP Server vs Redis MCP](https://www.anchorterminal.com/compare/clickhouse-mcp-server-vs-redis-mcp.md)
- [DBHub vs ReqRes MCP server](https://www.anchorterminal.com/compare/dbhub-vs-reqres-mcp.md)
- [Neon MCP Server vs ReqRes MCP server](https://www.anchorterminal.com/compare/neon-mcp-vs-reqres-mcp.md)
- [ObsessionDB vs ReqRes MCP server](https://www.anchorterminal.com/compare/obsessiondb-vs-reqres-mcp.md)
- [PlanetScale MCP Server vs ReqRes MCP server](https://www.anchorterminal.com/compare/planetscale-mcp-vs-reqres-mcp.md)
- [Postgres MCP Pro vs ReqRes MCP server](https://www.anchorterminal.com/compare/postgres-mcp-pro-vs-reqres-mcp.md)
- [PostgreSQL (archived MCP reference server) vs ReqRes MCP server](https://www.anchorterminal.com/compare/postgres-reference-server-archived-vs-reqres-mcp.md)
- [ReqRes MCP server vs Snowflake-managed MCP server](https://www.anchorterminal.com/compare/reqres-mcp-vs-snowflake-managed.md)
- [ReqRes MCP server vs Supabase API + MCP](https://www.anchorterminal.com/compare/reqres-mcp-vs-supabase-mcp.md)
- [MCP Toolbox for Databases vs ReqRes MCP server](https://www.anchorterminal.com/compare/mcp-toolbox-databases-vs-reqres-mcp.md)
- [MongoDB MCP Server vs ReqRes MCP server](https://www.anchorterminal.com/compare/mongodb-mcp-vs-reqres-mcp.md)
- [Redis MCP vs ReqRes MCP server](https://www.anchorterminal.com/compare/redis-mcp-vs-reqres-mcp.md)

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Query this catalogue directly over MCP: https://www.anchorterminal.com/mcp (Streamable HTTP, no key). How: https://www.anchorterminal.com/agents/#mcp