aid: datamuse name: Datamuse description: >- Datamuse operates a word-finding query engine and lexical search service for developers, educators, and creative-writing applications. The Datamuse API exposes a /words endpoint that finds words matching a rich combination of semantic, phonetic, orthographic, and vocabulary constraints (means-like, sounds-like, spelled-like, synonyms, antonyms, hypernyms, meronyms, triggers, rhymes, homophones, and more) plus a /sug autocomplete endpoint. Free for non-commercial use up to 100,000 requests per day with no API key required; commercial use, custom vocabularies, and higher rate limits are available via a paid commercial agreement. Datamuse also runs OneLook, OneLook Thesaurus, RhymeZone, Rimar.io, and CivicSearch — consumer-facing word search tools built on the same lexical infrastructure. url: https://www.datamuse.com/api/ specificationVersion: '0.20' created: '2026-05-28' modified: '2026-05-29' x-source: public-apis/public-apis x-category: Open Source Projects x-type: company x-tier: 3 x-tier-reason: bulk-registered-from-public-apis image: https://kinlane-productions.s3.amazonaws.com/apis-json/apis-json-logo.jpg tags: - Word Finding - Lexical Search - Natural Language - Vocabulary - Synonyms - Antonyms - Rhymes - Phonetics - Semantic Search - Reverse Dictionary - Autocomplete - Wordplay - Creative Writing - Vocabulary Apps - Word Games - Linguistics - Open Source Projects - Public APIs apis: - aid: datamuse:datamuse-api name: Datamuse API description: >- The Datamuse REST API exposes two operations covering word-finding (/words) and autocomplete suggestions (/sug). The /words endpoint accepts a rich combination of constraint parameters — semantic (ml, rel_syn, rel_ant, rel_trg, rel_spc, rel_gen, rel_com, rel_par, rel_jja, rel_jjb), phonetic (sl, rel_rhy, rel_nry, rel_hom, rel_cns), orthographic (sp with wildcards), and vocabulary (v=en|es) — plus ranking hints (topics, lc, rc) and result controls (max, md, qe, ipa). No authentication required for free non-commercial use up to 100k requests/day. humanURL: https://www.datamuse.com/api/ baseURL: https://api.datamuse.com tags: - Word Finding - Lexical Search - Natural Language properties: - type: Documentation url: https://www.datamuse.com/api/ - type: APIReference url: https://www.datamuse.com/api/ - type: OpenAPI url: openapi/datamuse-openapi.yml - type: JSONSchema url: json-schema/datamuse-word-schema.json - type: JSONSchema url: json-schema/datamuse-suggestion-schema.json - type: JSONStructure url: json-structure/datamuse-word-structure.json - type: JSONStructure url: json-structure/datamuse-suggestion-structure.json - type: JSON-LD url: json-ld/datamuse-context.jsonld - type: Example url: examples/datamuse-getwords-example.json - type: Example url: examples/datamuse-getsuggestions-example.json - type: RateLimits url: rate-limits/datamuse-rate-limits.yml - type: Pricing url: plans/datamuse-plans-pricing.yml operations: - method: GET endpoint: /words summary: Find Words Matching Constraints - method: GET endpoint: /sug summary: Get Autocomplete Suggestions common: - type: Website url: https://www.datamuse.com/ - type: Documentation url: https://www.datamuse.com/api/ - type: APIReference url: https://www.datamuse.com/api/ - type: Pricing url: https://www.datamuse.com/api/ - type: TermsOfService url: https://www.datamuse.com/api/ - type: PrivacyPolicy url: https://www.datamuse.com/api/ - type: Support url: https://www.datamuse.com/api/ - type: SpectralRules url: rules/datamuse-rules.yml - type: Vocabulary url: vocabulary/datamuse-vocabulary.yml - type: NaftikoCapability url: capabilities/shared/datamuse-shared.yaml - type: NaftikoCapability url: capabilities/word-discovery.yaml - type: NaftikoCapability url: capabilities/rhyme-and-phonetics.yaml - type: NaftikoCapability url: capabilities/reverse-dictionary.yaml - type: NaftikoCapability url: capabilities/autocomplete.yaml - type: Plans url: plans/datamuse-plans-pricing.yml - type: RateLimits url: rate-limits/datamuse-rate-limits.yml - type: FinOps url: finops/datamuse-finops.yml - type: PublicAPIsListing url: https://github.com/public-apis/public-apis - type: SDK url: https://github.com/sjblair/Datamuse4J - type: SDK url: https://github.com/gmarmstrong/python-datamuse - type: SDK url: https://github.com/ansteh/datamuse - type: SDK url: https://github.com/ezefranca/datamuse-swift - type: SDK url: https://github.com/owenvoke/datamuse-php-api-wrapper - type: SDK url: https://github.com/kostaspt/go-datamuse - type: SDK url: https://github.com/slogemann1/datamuse-api-wrapper - type: SDK url: https://github.com/benhess02/DatamuseDotNet - type: SDK url: https://github.com/mosegontar/rubymuse - type: Tools url: https://github.com/lacausecrypto/datamuse-mcp - type: Tools url: https://github.com/pipeworx-io/mcp-datamuse - type: Tools url: https://github.com/bhayanak/datamuse-mcp-server - type: Tools url: https://github.com/pipeworx-io/mcp-words - type: Tools url: https://github.com/Eyalm321/multilingual-dictionary-mcp - type: Features data: - name: Means Like (ml) description: Reverse-dictionary semantic constraint finding words whose meaning matches an input string of any length. - name: Sounds Like (sl) description: Phonetic constraint returning words pronounced similarly to a given input using a text-to-phonemes algorithm. - name: Spelled Like (sp) description: Orthographic constraint with wildcard pattern matching (* for any chars, ? for a single char). - name: Predefined Relations (rel_*) description: Twelve lexical relations including synonyms, antonyms, hypernyms, hyponyms, holonyms, meronyms, triggers, frequent followers/predecessors, rhymes, near-rhymes, homophones, and consonant matches. - name: Context Ranking description: Topics, left-context (lc), and right-context (rc) parameters skew results toward a document theme or surrounding words. - name: Lexical Metadata (md) description: Optional metadata flags add definitions, parts of speech, syllable counts, pronunciations, and corpus frequency to each word. - name: Pronunciation Formats description: Default Arpabet pronunciations or IPA via the ipa flag, drawing on the CMU Pronouncing Dictionary. - name: Multilingual Vocabularies description: Default English (550k terms) and Spanish (500k terms) vocabularies; custom domain vocabularies available on request. - name: Autocomplete (/sug) description: Intelligent prefix suggestions with spelling correction and semantic fallback when exact matches are unavailable. - name: No API Key Required description: Free non-commercial use up to 100,000 requests per day without an account or API token; HTTPS and HTTP both supported. - name: Query Echo (qe) description: Prepends the result list with a record describing the query string, useful for one-shot word-metadata lookups. - type: UseCases data: - name: Vocabulary Building Apps description: Power flashcards, quizzes, and language-learning apps with synonyms, antonyms, and related-word lookups. - name: Creative Writing Tools description: Drive rhyme finders, thesaurus add-ins, and reverse-dictionary lookups for poetry, songwriting, and copywriting. - name: Word Games and Puzzles description: Generate clues, fill patterns with sp wildcards, and validate word lists for crosswords, hangman, and word ladders. - name: Autocomplete and Type-Ahead description: Provide intelligent prefix suggestions with spelling correction in search bars and form fields. - name: Educational Software description: Add definitions, syllable counts, and pronunciations to reading apps, ESL tools, and accessibility software. - name: Search Query Expansion description: Expand a user's search terms with semantically related words to improve recall in document or product search. - name: NLP Pre-Processing description: Look up word relations, frequencies, and pronunciations as features for downstream NLP pipelines. - name: Brand and Product Naming description: Combine sounds-like, means-like, and spelled-like constraints to brainstorm brand, domain, or product names. - type: Integrations data: - name: OneLook description: Datamuse's flagship word search engine indexing 10M+ words across 1000+ dictionaries; built on the same backend. - name: OneLook Thesaurus description: Reverse-dictionary and thesaurus product available on web, as a Google Docs add-on, and as an iOS/Mac app. - name: RhymeZone description: Rhyming dictionary and writing tool partnered with Merriam-Webster, available on web and mobile. - name: Rimar.io description: Spanish-language rhyming dictionary and thesaurus powered by Datamuse's Spanish vocabulary. - name: CivicSearch description: Local government meeting search engine covering 700+ jurisdictions across the US and Canada. - name: WordNet 3.0 description: Princeton lexical database supplying synonyms, antonyms, hypernyms, hyponyms, holonyms, and meronyms. - name: CMU Pronouncing Dictionary description: Source for Arpabet pronunciations and the basis for phonetic constraints (sl, rel_rhy, rel_hom, rel_cns). - name: Google Books Ngrams description: Corpus underpinning frequency scores and the rel_jja, rel_jjb, rel_bga, rel_bgb statistical relations. - name: Wiktionary description: Source of definitions returned via the md=d metadata flag. - name: word2vec / Paraphrase Database description: Corpus and embedding sources contributing to means-like and trigger relations. - name: Obsidian Wordy Plugin description: Community plugin embedding Datamuse-powered thesaurus and reverse-dictionary directly into Obsidian. - name: Model Context Protocol Servers description: Multiple community MCP servers (lacausecrypto/datamuse-mcp, pipeworx-io/mcp-datamuse, bhayanak/datamuse-mcp-server) expose the API to LLM agents. - type: Solutions data: - name: Free Non-Commercial Tier description: Up to 100,000 requests per day with no API key, no signup, suitable for prototypes, hobby projects, research, and non-commercial education. - name: Commercial Plan description: Custom contract for production traffic in customer-facing applications, higher quotas, custom vocabularies, and SLA — pricing on request. - name: Custom Vocabulary Hosting description: Domain-specific term lists (medical, legal, gaming, internal jargon) hosted on Datamuse infrastructure with all standard relations. maintainers: - FN: Kin Lane email: kin@apievangelist.com