AssemblyAI

Fair

Agent Native Score

Free TierAPI Key AuthOpenAPI Spec

AssemblyAI is a speech-to-text and audio intelligence platform that provides API access to automatic speech recognition (ASR), speaker detection, and other audio analysis features. It enables agents to transcribe and understand audio content programmatically.

Categories: Audio · Speech Recognition · Nlp

#2 of 5 in Audio · #1 of 2 in Speech Recognition · #2 of 5 in Nlp

Checklist Breakdown

13 of 33 checks passed. 14 unscored.

Discovery 63%

Can an agent find and understand this tool without a web search?

✓ Published OpenAPI/Swagger spec

✗ Has llms.txt or llms-full.txt

✗ Has an MCP server (official or well-maintained)

✗ MCP server listed in a public registry

✓ API reference docs are publicly accessible

✓ Docs include runnable code examples

✓ Has a public changelog or release notes

✓ Has a public status page

Auth & Onboarding 50%

Can an agent create an account and get credentials without human intervention?

✗ Signup does not require CAPTCHA

✗ Signup does not require phone verification

✓ Supports API key auth (not only OAuth)

✗ API key obtainable without manual approval

✓ No mandatory billing info to start

✓ Can sign up without creating an organization

Pricing 100%

Can an agent operate autonomously without upfront payment or contracts?

✓ Has a free tier

✓ Usage-based pricing available

✓ No minimum contract or commitment

✓ Pricing page is public (no 'contact sales')

✓ Free tier sufficient for testing (not just a trial)

Agent Tooling Not yet scored

How well does the API work for non-human consumers?

— SDK available in 2+ languages

— Structured error responses (JSON with error codes)

— Idempotency support on write endpoints

— Pagination on list endpoints

— Webhook/event support

— Sandbox or test mode available

— Rate limit headers in responses

— Consistent REST resource naming

Reliability Not yet scored

Does the tool fail gracefully when an agent makes a mistake?

— Meaningful error messages (not just 500)

— 429 responses include Retry-After header

— Documented uptime SLA (99.9%+)

— Graceful degradation under rate limits

— Request IDs in responses for debugging

— API versioning supported

Reviewer Notes

AssemblyAI has good API documentation and a published OpenAPI spec, making discovery relatively straightforward. The API tooling is solid with clear request/response structures and structured output options (JSON). However, account creation requires email verification and manual dashboard interaction—agents cannot autonomously sign up. The free tier (50 minutes/month) and sandbox availability help, but the pricing model requires credit card upfront for production use. Reliability is strong with good uptime reputation and clear error messages. Main weakness: no MCP server and mandatory human account setup. Main strength: well-designed REST API with good structured responses ideal for agent integration.

AssemblyAI

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