A WireMock simulation of Anthropic's REST API — covering the Messages API, models, message batches, files, and skills.
A shared instance of this template runs on a public endpoint — call it right now from curl, an SDK, or an AI agent. Responses are fixed examples and behavior can't be changed; rate limits apply.
Jump to the endpoints ↓Run this template as a mock API in WireMock Cloud for a private instance you control — edit stubs, add stateful scenarios, use dynamic response templating, and inspect requests in the log.
Open in WireMock Cloud (free) →Live sandbox · no signup, no API key
A running WireMock Cloud instance of this template, callable right now from a terminal, a script, or an AI agent.
Endpoints
GET List available Claude models
curl -s -X GET 'https://2284d.wiremockapi.cloud/v1/models'POST Create a message (Claude chat completion)
curl -s -X POST 'https://2284d.wiremockapi.cloud/v1/messages' \
-H 'Content-Type: application/json' \
-d '{"model":"claude-opus-4-20250514","max_tokens":256,"messages":[{"role":"user","content":"Hello, Claude"}]}'Spec catalog — Anthropic API (2023-06-01) · 24 endpoints
| Method | Path | Summary |
|---|---|---|
| POST | /v1/complete | Create a Text Completion |
| GET | /v1/files | List Files |
| POST | /v1/files | Upload File |
| DELETE | /v1/files/{file_id} | Delete File |
| GET | /v1/files/{file_id} | Get File Metadata |
| GET | /v1/files/{file_id}/content | Download File |
| POST | /v1/messages | Create a Message |
| GET | /v1/messages/batches | List Message Batches |
| POST | /v1/messages/batches | Create a Message Batch |
| DELETE | /v1/messages/batches/{message_batch_id} | Delete a Message Batch |
| GET | /v1/messages/batches/{message_batch_id} | Retrieve a Message Batch |
| POST | /v1/messages/batches/{message_batch_id}/cancel | Cancel a Message Batch |
| GET | /v1/messages/batches/{message_batch_id}/results | Retrieve Message Batch results |
| POST | /v1/messages/count_tokens | Count tokens in a Message |
| GET | /v1/models | List Models |
| GET | /v1/models/{model_id} | Get a Model |
| GET | /v1/skills | List Skills |
| POST | /v1/skills | Create Skill |
| DELETE | /v1/skills/{skill_id} | Delete Skill |
| GET | /v1/skills/{skill_id} | Get Skill |
| GET | /v1/skills/{skill_id}/versions | List Skill Versions |
| POST | /v1/skills/{skill_id}/versions | Create Skill Version |
| DELETE | /v1/skills/{skill_id}/versions/{version} | Delete Skill Version |
| GET | /v1/skills/{skill_id}/versions/{version} | Get Skill Version |
Unauthenticated WireMock Cloud demo sandbox for Anthropic — not an official Anthropic sandbox, and it returns simulated example data only.
The template mirrors Anthropic's REST surface as published in spec version 2023-06-01. Its core is the Messages endpoint, and the stub answers with everything a production reply carries — assistant content blocks, a stop reason, and a per-request usage object with input and output token counts — so client code written against real Claude responses parses these without modification.
The official Anthropic SDKs accept a base-URL override, so redirecting a client takes two constructor arguments — the calls themselves don't change:
Agents and tools that use the SDK internally can be redirected the same way through the ANTHROPIC_BASE_URL environment variable — no code changes at all. Swap in your own mock's URL once you've created one in WireMock Cloud.
Because every response is deterministic, this fills the gap for CI suites that can't depend on live model availability, for developing agent loops without burning tokens, and for demoing a Claude-integrated feature when no real key is in the room.
import anthropic
# the sandbox URL, or your own mock's —
# the api_key is accepted but never validated
client = anthropic.Anthropic(
base_url="https://2284d.wiremockapi.cloud",
api_key="any-value",
)
reply = client.messages.create(
model="claude-opus-4-6",
max_tokens=256,
messages=[{"role": "user", "content": "Hello, Claude"}],
)
print(reply.content[0].text)No. The mock accepts any x-api-key value and never validates it. Don't send a real key to the shared sandbox, though — it's a public, unauthenticated endpoint, and no live credential should ever travel to it.
No model runs behind the mock. Each reply is a recorded example: production structure, fixed text. That fixedness is the feature — assertions never flake because Claude phrased an answer differently between runs.
Not in the sandbox — a request with stream set to true gets the complete JSON message rather than server-sent events. Test the non-streaming path here, or shape a custom SSE stub in your own WireMock Cloud copy.
The sandbox serves happy paths only. In your WireMock Cloud copy, add stubs that return Anthropic-shaped error bodies — a rate_limit_error with a 429, an overloaded_error with a 529 — and point your retry logic at them: a scenario you can't trigger on demand against the real API.
Vendor names identify APIs represented by WireMock template sources. This page does not imply vendor endorsement, certification, partnership, or official integration status.