01 / Normalize
Contract graph
Parse OpenAPI into one stable, traceable representation of operations, schemas, auth, errors, and workflows.
OpenAPI 3.0 + 3.1
The API-to-agent interface compiler
Build APIs for humans and agents.
Turn one OpenAPI contract into production TypeScript and Python SDKs, authenticated MCP servers, and agent integrations that are continuously tested.
01
OpenAPI
02
TS + Python
03
MCP
04
Agent evals
05
GitHub PR
Stripe case study
Stripe catalog · verified evidence
25 pairs
Interface testLiteralFiber
Task completion96%100%
Tool calls / run11.71.0
Stripe API errors330
Agent tokens / run39,7641,904
Agent latency / run53.1s13.7s
Published benchmark
25paired runs
Release confidence
Read the full technical case study
Method, charts, raw data, and failure analysis → Published benchmark 01 / Stripe
One reviewed workflow replaced nine literal tools.
Same model, tasks, settings, and Stripe test-mode transport. Every public number comes from the verified 25-pair dataset.
Verified
95.2%
fewer tokens
Verified
91.4%
fewer calls
Verified
74.1%
lower latency
Verified
33 → 0
Stripe API errors
One compiler · every interface
Ship the interface. Prove the integration.
Fiber treats SDKs, MCP tools, and agent documentation as projections of the same contract—then tests the workflows that matter before a change ships.
02 / Generate
Human interfaces
Produce idiomatic TypeScript and Python clients with reviewable, deterministic diffs.
TypeScript + Python
03 / Project
Agent interfaces
Turn API operations into curated MCP tools with authentication and explicit safety boundaries.
Remote MCP server
04 / Prove
Compatibility evidence
Run the same real tasks across providers and report success, errors, retries, tokens, latency, and cost.
Trace-backed evals
Compatibility matrix
Provider-neutral at the core.
Surface
OpenAI
Claude
Gemini
TypeScript
Python
MCP
Stainless migration
Keep the SDK. Keep the history. Keep your changes.
Fiber maps generated and user-owned code, regenerates into a clean tree, and surfaces ambiguous conflicts instead of silently overwriting them.
01Import
02Map
03Maintain
30-day build
One hard API. One complete proof loop.
The first milestone is not five languages or a broad self-serve platform. It is one production-quality interface set with evidence that survives review.
Days 01–0501
Contract + change engine
Normalize two real OpenAPI versions and produce deterministic breaking-change evidence.
Days 06–1202
Production TypeScript target
Generate one client that compiles, packages, installs, and completes real sandbox tasks.
Days 13–2403
Python + MCP + evals
Run one task suite through every interface and each provider adapter.
Days 25–3004
GitHub + migration proof
Open the first trace-backed PR and migrate one permissioned Stainless repository.
Release gates
Deterministic contract diff
Generated packages compile
Task assertions pass
Every score links to a trace
Design partner 01
Bring Fiber one difficult API.
We want auth, pagination, uploads, unions, structured errors, or long-running jobs—the edge cases that make the compiler real.
Review the workflowEvery API change becomes a reviewable compatibility PR.
OpenAI · Claude · Gemini · MCP · TypeScript · Python