# AX Check: mercury.com
Checked 2026-09-19.

Mercury's CLI and pricing are clear, but the docs index is broken.
llms.txt returns a dead link, and the homepage won't serve plain text. But the CLI README and pricing page give agents everything needed to install, log in, and price out a plan.

## Onboarding needs a login

## Coding sessions
All three independent sessions completed and read pricing straight off mercury.com or the CLI README, each reporting the same plan tiers (free, Plus, Pro) plus fees like the FX and Treasury charges, with no login wall blocking access to that information.

### DeepSeek V4 Pro
[View public run](https://agents.withgauge.com/p/runs/2b349694-2988-4b79-83ab-6f937e88b434) · [Read transcript](https://www.ax-check.com/mercury.com/sessions/deepseek.json)
README.md and final output give a pricing table per 1M tokens with explicit assumptions: promo discount vs regular price, free 100M-token grant, pay-as-you-go billing basis, and rate-limit tiers.
#### End-to-end onboarding
- **Onboarding needs a login**: The agent researched Mercury's hosted API thoroughly (docs, OpenAPI spec, model list) and wrote a working example script, but never obtained a real Inception API key. It had no signup automation available and explicitly asked the human for a key at the end. It confirmed the unauthenticated GET /v1/models endpoint works, but the authenticated chat completion request failed with 401 using a placeholder key, so no authenticated product operation was demonstrated.
  Event 62:

  ```text
  {"error":{"message":"Incorrect API key provided","type":"authentication_error","param":null,"code":"invalid_api_key"}}
  ```
  Event 85:

  ```text
  HTTP 401: {"error":{"message":"Incorrect API key provided","type":"authentication_error","param":null,"code":"invalid_api_key"}}
  ```
  Event 91:

  ```text
  I don't have an Inception API key in this environment, so a real completion can't run yet.
  ```

#### Hallucinated URLs
None identified in this transcript.

#### Blockers
- **No API key available to run authenticated calls**: The agent never had an INCEPTION_API_KEY in the sandbox environment and had no way to self-serve one (no account creation flow was attempted or available). All authenticated requests to /v1/chat/completions returned 401. This is a missing-credentials limitation of the test environment, not a product defect — the platform documents how a human would generate keys via its dashboard.
  Event 62:

  ```text
  {"error":{"message":"Incorrect API key provided","type":"authentication_error","param":null,"code":"invalid_api_key"}}
  ```
  Event 91:

  ```text
  I don't have an Inception API key in this environment, so a real completion can't run yet.
  ```

#### Suggested Changes
None identified in this transcript.

### Kimi K3
[View public run](https://agents.withgauge.com/p/runs/cc14cf59-1aff-405e-98ad-76f72b48a556) · [Read transcript](https://www.ax-check.com/mercury.com/sessions/kimi.json)
Final output lists Core $0/mo, Plus $35/mo (waived until Dec 31 2026), Pro $350/mo, sourced live from mercury.com/pricing (seq 12/14), with assumption noted that API access itself isn't separately metered but some features sit behind Plus.
#### End-to-end onboarding
- **Onboarding needs a login**: Agent never obtained a Mercury API token. It searched the environment for credentials, found none, and concluded a human must create a Mercury account and API token before any authenticated call can be made. The example script was written but never executed against the live API.
  Event 8:

  ```text
  env | grep -iE "api_key|token" | sed 's/=.*/=<present>/'
  ```
  Event 21:

  ```text
  obtaining an API token requires a Mercury account, and opening one requires a US-incorporated business plus identity verification. No token exists in this environment, so I can't execute the example.
  ```

#### Hallucinated URLs
- **Guessed SDK package names that do not exist**: Agent probed pypi and npm for speculative Mercury SDK package names it invented, both of which failed to resolve to a real Mercury SDK, before settling on plain REST calls instead.
  Event 13:

  ```text
  timeout 15 curl -s https://pypi.org/pypi/mercury-sdk/json | head -c 300; echo; timeout 15 curl -s https://registry.npmjs.org/@mercury-api/sdk | head -c 200
  ```
  Event 15:

  ```text
  {"error":"Not found"}
  ```

#### Blockers
- **No self-service way to get a Mercury API token**: Mercury Bank requires opening a real bank account (US-incorporated business, identity verification) before an API token can be issued from the dashboard. This is normal product behavior for a banking product, not a defect, but it fully blocked authenticated execution in this sandboxed session since no human could complete that verification step.
  Event 21:

  ```text
  The only thing I can't do is the one manual step in the quickstart: **obtaining an API token requires a Mercury account**, and opening one requires a US-incorporated business plus identity verification.
  ```

#### Suggested Changes
- **Publish an official SDK package under a discoverable name**: The agent tried plausible package names (mercury-sdk on PyPI, @mercury-api/sdk on npm) and found nothing usable, landing on unrelated or missing packages. If an official SDK exists, list its exact package name and install command on docs.mercury.com's quickstart page so agents and developers do not have to guess; verify by searching PyPI/npm for the documented name and confirming it resolves.
  Event 13:

  ```text
  timeout 15 curl -s https://pypi.org/pypi/mercury-sdk/json | head -c 300; echo; timeout 15 curl -s https://registry.npmjs.org/@mercury-api/sdk | head -c 200
  ```
  Event 15:

  ```text
  {"error":"Not found"}
  ```

### Qwen 3.8 Max
[View public run](https://agents.withgauge.com/p/runs/c03deded-420b-4875-8cca-73a1bcb90621) · [Read transcript](https://www.ax-check.com/mercury.com/sessions/qwen.json)
Final output states API is free with a Mercury account ($0 for read-only use), lists Plus $35/mo, Pro $350/mo, Treasury fee 0.15-0.60%/yr on balances >$250K, FX 1% fee — each tied to a named plan/workload assumption sourced from the pricing page scrape (seq 42-103).
#### End-to-end onboarding
- **Onboarding needs a login**: Agent researched Mercury's real hosted API thoroughly (docs, OpenAPI, sandbox endpoints) and built a working read-only Python CLI against the sandbox base URL. It confirmed the sandbox environment is live (proper 401 errors for missing/bad tokens), but could not obtain a real API token itself: token creation requires logging into a Mercury dashboard, and the sandbox signup page blocked non-browser access. No authenticated operation against real account data was ever completed.
  Event 44:

  ```text
  == sandbox signup ==
  403
  ```
  Event 78:

  ```text
  Mercury API error: HTTP 401 from https://api-sandbox.mercury.com/api/v1/accounts?limit=10: {'errorCode': 'noTokenInDB', 'message': 'No matching token found'}
  ```
  Event 128:

  ```text
  an API token can only be minted from a logged-in Mercury dashboard, and sandbox.mercury.com/signup returns 403 to non-browser clients, so I can't create the sandbox account myself
  ```

#### Hallucinated URLs
None identified in this transcript.

#### Blockers
- **Sandbox signup blocks non-browser signup, so no token could be minted**: Mercury requires creating a sandbox account via a browser-based signup flow to generate an API token; the agent's non-interactive curl request to the signup URL was rejected with 403. This is a product/test-environment limitation (self-serve signup is gated against non-browser/automated clients), not an agent mistake — the agent correctly identified it needed human action here.
  Event 44:

  ```text
  == sandbox signup ==
  403
  ```

#### Suggested Changes
- **Fix the pricing page's stale promo price for Mercury Plus**: On mercury.com/pricing, the visible price digit for Mercury Plus renders as $29.90/mo while the page's own JSON-LD schema states $35/mo. Check by comparing the rendered price display against the pageSchema JSON-LD offers block on the same page; align them to avoid quoting conflicting prices to prospective developers.
  Event 102:

  ```text
  Mercury Plus $ <div class=\"styles_priceDigitOuterContainer__KjOoE\" 
  ```
  Event 98:

  ```text
  Mercury Plus ($35/mo), and Mercury Pro ($350/mo).
  ```

### Task given to each agent
Help me build a simple example using Mercury. Tell me how pricing works, and briefly tell me whether this product will be easy for you to manage. Let me know if you get blocked. If this product has no developer workflow you can act on, say so plainly and stop. Stay light: use the hosted product through its SDK or API. Do not start local service stacks or wait for long-running commands; if the quickstart requires either, say so plainly and stop.

No product credentials were supplied and no purchases were authorized.

## Score: C · 60/100 (provisional)
Grades come from completed site checks. Coding sessions and skipped checks do not affect the score.

### Clarity
- **Failed** — Homepage answers Markdown requests

  ```text
  Homepage returned text/html even when Markdown was requested via Accept header.
  ```

- **Failed** — llms.txt provides an actionable documentation index

  ```text
  https://mercury.com/llms.txt returns HTTP 410, so no documentation index is available.
  ```

- **Skipped** — llms.txt provides navigation guidance

  ```text
  llms.txt returned 410, so no navigation guidance could be evaluated.
  ```

- **Skipped** — llms.txt mentions offered API, MCP, and skills

  ```text
  llms.txt returned 410, so no API/MCP/skills mentions could be evaluated.
  ```

- **Pass** — A compact guide representation exists

  ```text
  docs.mercury.com serves markdown; MCP guide fetched as text/markdown with .md convention.
  ```

- **Pass** — A focused guide is directly retrievable

  ```text
  MCP connection guide retrieved directly as markdown with concrete setup steps.
  ```

- **Pass** — Equivalent instructions fit a token budget

  ```text
  MCP guide is 2286 tokens, well under the 8000-token budget.
  ```

- **Skipped** — Product-docs links survive format changes

  ```text
  Homepage Markdown unsupported, so link preservation across formats cannot be judged.
  ```

- **Skipped** — The compact guide is independently actionable

  ```text
  No compact agent guide fetched; only MCP connection doc and truncated API page available.
  ```

- **Skipped** — Install and next-step links resolve

  ```text
  Install/next-step links not fetched; support Getting Started returned 403 Cloudflare challenge.
  ```


### Onboarding
- **Pass** — Docs lead to a relevant quickstart

  ```text
  CLI README provides a concrete quick start: mercury login, accounts list, payments create.
  ```

- **Pass** — Installation commands are extractable

  ```text
  README gives extractable install commands: curl install.sh, nix, and go install.
  ```

- **Pass** — Code examples are available without interaction

  ```text
  README shows inline code examples for login, payments, apply, and file args.
  ```

- **Pass** — Prerequisites and auth boundaries are explicit

  ```text
  README documents MERCURY_API_KEY, secret-token prefix, and token creation URL.
  ```


### Pricing
- **Pass** — Pricing is readable without interaction

  ```text
  Mercury pricing page renders plan prices and feature lists directly in fetched HTML.
  ```

- **Pass** — Prices are stated, not gated

  ```text
  Prices stated: $0/mo, $29.90/mo Plus, $299/mo Pro, $240/yr Personal.
  ```

- **Pass** — Pricing units and limits are explicit

  ```text
  Units explicit: per month, per transaction, $250K Treasury minimum, 1% FX fee.
  ```

- **Pass** — Agents identify pricing and its assumptions

  ```text
  3 of 3 sessions were judged on pricing; 0 fell short. DeepSeek V4 Pro: README.md and final output give a pricing table per 1M tokens with explicit assumptions: promo discount vs regular price, free 100M-token grant, pay-as-you-go billing basis, and rate-limit tiers. Kimi K3: Final output lists Core $0/mo, Plus $35/mo (waived until Dec 31 2026), Pro $350/mo, sourced live from mercury.com/pricing (seq 12/14), with assumption noted that API access itself isn't separately metered but some features sit behind Plus. Qwen 3.8 Max: Final output states API is free with a Mercury account ($0 for read-only use), lists Plus $35/mo, Pro $350/mo, Treasury fee 0.15-0.60%/yr on balances >$250K, FX 1% fee — each tied to a named plan/workload assumption sourced from the pricing page scrape (seq 42-103). This behavioural item does not affect the fast grade.
  ```


### Activation
- **Pass** — An API reference or OpenAPI spec is reachable

  ```text
  Mercury API page links to docs.mercury.com REST API reference with sandbox and token guidance.
  ```

- **Pass** — An MCP server is documented and well-formed

  ```text
  MCP guide documents server URL, OAuth flow, client setup, and read-only scope.
  ```

- **Pass** — A CLI install path is documented

  ```text
  CLI README documents curl, Nix, and Go install paths plus quickstart commands.
  ```

- **Skipped** — SDK packages resolve on their registries

  ```text
  No registry lookup result for a Mercury SDK or packaged CLI package was supplied.
  ```

- **Skipped** — Agent skills are published

  ```text
  No agent skills documentation was fetched or offered in the evidence.
  ```



[Full report data](https://www.ax-check.com/mercury.com/report.json)