# DID.is

> Resolve decentralized identifiers (DIDs) and verify credential proofs with DID.is and its verification API. Inspect evidence and understand its limits.

Public API base URL: https://did.is/api (anonymous, no key). OpenAPI 3.1: https://did.is/api/openapi.json. Budgets: 20 requests/min standard, 10 requests/min for intensive operations; on 429 honour Retry-After. DID.is-native /v1 JSON HTTP API errors use RFC 9457 problems with a stable code. W3C DID Resolution wraps resolution errors in didResolutionMetadata.error; SSE streams emit error events after opening, and MCP uses its protocol error envelopes, not top-level problem JSON. Account authentication, edge/proxy and transport failures may use other response shapes; inspect status and content type before parsing.

Project API keys (optional, https://did.is/pricing): send `Authorization: Bearer <key>` and one `Idempotency-Key` per call to POST https://did.is/api/v1/customer/{resolve, mcp/inspect, a2a/inspect, agents/authorize, agents/verify-delegation} or GET https://did.is/api/v1/customer/usage. Same JSON as the public routes; the key only changes limits (monthly team allowance, RateLimit-Policy/RateLimit headers). Never send a key to public routes.

## MCP server

- Remote MCP endpoint: https://did.is/mcp (Streamable HTTP, protocol 2026-07-28 with 2025-11-25 fallback; anonymous, read-only).
- Tools: resolve_did, verify_credential, inspect_mcp_server, inspect_a2a_agent, authorize_tool_call, evaluate_policy, search_directory.
- Results carry a short summary and structuredContent; third-party text is under `untrusted`. A spent budget is a tool error with retryAfterSeconds.
- [Setup for Claude Code, Cursor and VS Code](https://did.is/developers#mcp)

## Documentation

- [Documentation](https://docs.did.is/): Guides, concepts and API reference.
- [Documentation index for LLMs](https://docs.did.is/llms.txt): Every documentation page with a one-line summary.
- [Use cases](https://docs.did.is/start/use-cases/): Concrete questions DID.is answers.
- [Link your websites to your DID](https://docs.did.is/build/linked-websites/): alsoKnownAs and DID Configuration, confirmed in both directions.

## Web app

- [Resolver](https://did.is/): Paste a DID, credential, JWT or URL and read the evidence.
- [Credential Studio](https://did.is/verify): Verify W3C verifiable credentials and SD-JWT VCs.
- [Agents](https://did.is/agents): Inspect MCP servers and A2A agent cards; verify delegation chains.
- [MCP server check](https://did.is/tools/mcp-check): Check a public MCP server's tools, fingerprints and drift; README badge.
- [Public MCP servers](https://did.is/tools/mcp-servers): Search the official MCP Registry by server name; each endpoint shows DID.is's last stored public check (not live). Default view: DID.is's own server as an example.
- [Policies](https://did.is/policies): Try declarative trust policies against a live DID.
- [Directory](https://did.is/discover): Opt-in public listings and verified control claims.
- [Developer center](https://did.is/developers): API reference, SDKs and runnable examples.
- [Standards](https://did.is/standards): Which specifications DID.is implements and how far.
- [Pricing](https://did.is/pricing): Free public API; paid plans for private resolution, agent check calls and monitoring.
- [Status](https://did.is/status): Live component status.

## API operations

- GET /1.0/identifiers/{did}: W3C DID Resolution (CR Draft)
- GET /v1/resolve/{did}: Resolve with evidence
- GET /v1/stream/{did}: Live resolution (SSE)
- GET /v1/dereference/{didUrl}: Dereference a DID URL
- GET /v1/history/{did}: Observation history
- GET /v1/diff/{did}: Semantic diff
- POST /v1/credentials/verify: Verify a credential
- POST /v1/policies/evaluate: Evaluate a policy
- GET /v1/mcp/inspect: Inspect an MCP server
- GET /v1/a2a/inspect: Inspect an A2A agent card
- POST /v1/agents/verify-delegation: Verify a delegation chain
- POST /v1/agents/authorize: Authorise a tool call
- GET /v1/fast-verify/did/{did}: Fast DID verdict
- POST /v1/fast-verify/jws: Verify a JWS against a DID
- GET /v1/graph/{did}: Evidence graph
- GET /v1/claims/{did}: Verified control claims
- GET /v1/directory: Search the directory
- GET /v1/agents/verify-tool: Check a registered agent
- GET /health: Health and capabilities
- GET /v1/status: Service status

## SDKs

- [TypeScript: @didis/client](https://www.npmjs.com/package/@didis/client)
- [Python: didis-py](https://pypi.org/project/didis-py/)