Rime

Converts input text to natural-sounding speech using linguistically-designed TTS models with fine-grained control over prosody (intonation, stress, rhythm) and emotional tone. The system supports four pre-built voice personas (Astra, Cupola, Vespera, Eliphas) each optimized for distinct emotional registers (happy, professional, casual, calm), enabling developers to match voice characteristics to content context without manual audio editing or post-processing.

Enables creation of custom voice clones from speaker samples, allowing developers to generate speech in branded or personalized voices without retraining underlying TTS models. Voice cloning is available at tier-dependent limits (2 clones in Growth tier, unlimited in Enterprise tier) and integrates seamlessly with the prosody and emotion control system, enabling consistent branded voice delivery across all generated content.

Provides built-in pronunciation dictionary and custom pronunciation rules to handle accurate synthesis of proper nouns, brand names, technical terms, numbers, and email addresses without requiring model retraining. The system applies pronunciation rules at synthesis time, enabling developers to define custom pronunciations for domain-specific vocabulary (e.g., pharmaceutical names, product SKUs, company names) and have them applied consistently across all generated speech without manual audio editing.

Implements character-based pricing model where costs are calculated per million characters synthesized, with two model tiers (Mist standard at $27-30/M chars, Arcana premium at $36-40/M chars) and volume discounts available at Growth tier ($5k/year minimum) and Enterprise tier. The system tracks character consumption across all synthesis operations and applies tier-based pricing automatically, enabling developers to predict costs based on content volume and choose between standard and premium models based on quality/cost tradeoffs.

Manages concurrent TTS synthesis operations with tier-dependent concurrency limits (5 concurrent for Pay as You Go, 20 concurrent for Growth, unlimited for Enterprise), enabling developers to parallelize long-form content generation and batch processing without blocking on sequential synthesis. The system queues excess requests and processes them within concurrency limits, allowing predictable scaling behavior and enabling cost-effective batch processing of large content volumes.

Provides Business Associate Agreement (BAA) and SOC 2 Type II attestation for Growth tier and above, enabling use in HIPAA-regulated environments (healthcare, medical transcription, patient communication) and other compliance-sensitive applications. The system implements security controls and audit logging required for compliance, allowing healthcare organizations and regulated enterprises to use Rime for voice synthesis without violating data protection regulations.

Enables Enterprise tier customers to deploy Rime voice synthesis in multiple deployment models: cloud-hosted (standard SaaS), on-premises (self-hosted), or within customer VPC (private cloud), providing flexibility for organizations with data residency, network isolation, or air-gap requirements. The system supports custom SLAs and deployment configurations negotiated per-customer, enabling enterprises to integrate voice synthesis into existing infrastructure without data egress or compliance concerns.

Provides free voice synthesis credits for early-stage startups through a grant program offering up to 3 months of free access, enabling founders and small teams to prototype and launch voice features without upfront costs. The program requires application and approval, targeting startups that meet eligibility criteria (not documented), and provides a pathway to paid tiers as startups scale.