fix(api): add configurable request retries

[jayy-77]

Summary

• Add tool-level HTTP retry support with exponential backoff (including Retry-After) for timeouts/network failures, 429s, and 5xx responses.
• Expose retry controls in the API block (Advanced) and the http_request tool.
• Update API block docs so the retries section matches behavior and configuration.

Test plan

• DATABASE_URL=postgres://postgres:postgres@localhost:5432/postgres bun run test tools/index.test.ts
• DATABASE_URL=postgres://postgres:postgres@localhost:5432/postgres bun run test tools/http/request.test.ts

Fixes #3225

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[greptile-apps]

Greptile Summary

Added configurable HTTP retry support with exponential backoff for the API block and http_request tool. The implementation includes intelligent defaults (2 retries for idempotent methods like GET/PUT/DELETE/HEAD, 0 for non-idempotent methods like POST/PATCH), respects Retry-After headers, and retries on timeouts, network failures, 429s, and 5xx responses.

• Exposed retry configuration in API block Advanced settings: retries, retry delay, max retry delay, and option to enable retries for non-idempotent methods
• Implemented robust retry logic with exponential backoff and jitter in tools/index.ts
• Added comprehensive test coverage for various retry scenarios
• Updated documentation to accurately reflect the new retry capabilities

The implementation is well-structured with proper error classification (avoiding retries on non-retryable errors like body size limits or blocked IPs) and configurable limits (max 10 retries).

Confidence Score: 4/5

• This PR is safe to merge with minor review of the retry loop logic
• The implementation is well-tested and comprehensive, with proper error handling and intelligent defaults. Score is 4 rather than 5 due to the complexity of the retry loop in executeToolRequest which warrants careful review to ensure all edge cases are handled correctly, particularly around response body consumption and cleanup.
• Pay close attention to apps/sim/tools/index.ts - the retry loop is complex and handles both errors and HTTP status retries

Important Files Changed

Filename	Overview
apps/sim/blocks/blocks/api.ts	Added retry configuration UI fields (retries, retryDelayMs, retryMaxDelayMs, retryNonIdempotent)
apps/sim/tools/http/request.ts	Added retry configuration with intelligent defaults for idempotent vs non-idempotent methods
apps/sim/tools/index.ts	Implemented core retry logic with exponential backoff, Retry-After support, proper error classification, and configurable parameters
apps/sim/tools/index.test.ts	Added comprehensive test coverage for retry behavior (5xx, 429, 4xx, timeout, idempotent vs non-idempotent)

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    Start[Start Request] --> Config[Resolve Retry Config]
    Config --> CheckMethod{Method Retryable?}
    CheckMethod -->|GET/PUT/DELETE/HEAD| DefaultRetries[Default: 2 retries]
    CheckMethod -->|POST/PATCH| CheckOverride{retryNonIdempotent?}
    CheckOverride -->|true| UserRetries[Use user retries]
    CheckOverride -->|false| NoRetries[0 retries]
    DefaultRetries --> Loop[Start Attempt Loop]
    UserRetries --> Loop
    NoRetries --> Loop
    
    Loop --> Attempt[Make HTTP Request]
    Attempt --> Success{Success?}
    
    Success -->|Response OK| Done[Return Response]
    Success -->|Error Thrown| ErrorCheck{Retryable Error?}
    Success -->|HTTP Error Status| StatusCheck{Retryable Status?}
    
    ErrorCheck -->|Timeout/Network| CheckLast1{Last Attempt?}
    ErrorCheck -->|Body Size/Blocked IP| Fail[Throw Error]
    ErrorCheck -->|Other Error| Fail
    
    StatusCheck -->|429 or 5xx| CheckLast2{Last Attempt?}
    StatusCheck -->|4xx| Fail
    
    CheckLast1 -->|Yes| Fail
    CheckLast1 -->|No| Backoff1[Calculate Backoff Delay]
    CheckLast2 -->|Yes| Fail
    CheckLast2 -->|No| CheckRetryAfter{Retry-After Header?}
    
    CheckRetryAfter -->|Yes| UseMax[Use max of backoff and Retry-After]
    CheckRetryAfter -->|No| Backoff2[Calculate Backoff Delay]
    
    Backoff1 --> Sleep1[Sleep with Delay]
    UseMax --> Sleep2[Sleep with Delay]
    Backoff2 --> Sleep2
    
    Sleep1 --> Loop
    Sleep2 --> Loop

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