Amp CLI stream-json-input multimodal repros (document/image/two-turn)

README.md

Amp CLI streaming JSON repros

Environment used:

• amp --version: 0.0.1774471707-g40b89f (released 2026-03-25)

Repros included

1. repro-document.ndjson -> repro-document.out.ndjson

• Command:
  • amp --execute --stream-json --stream-json-input --stream-json-thinking < repro-document.ndjson
• Observed:
  • Invalid message format on stdin line 1: message.content.1: Invalid input

2. repro-image-source-path.ndjson -> repro-image-source-path.out.ndjson

• Command:
  • amp --execute --stream-json --stream-json-input --stream-json-thinking < repro-image-source-path.ndjson
• Observed:
  • Invalid message format on stdin line 1: message.content.1: Invalid input

3. repro-image-source-only.ndjson -> repro-image-source-only.out.ndjson

• Command:
  • amp --execute --stream-json --stream-json-input --stream-json-thinking < repro-image-source-only.ndjson
• Observed:
  • Agent failed to complete the request.

4. repro-two-turn-delayed.sh -> repro-two-turn-delayed.out.ndjson

• Command:
  • bash repro-two-turn-delayed.sh
• Behavior:
  • sends first user JSON line, waits 5 seconds, sends second user JSON line
• Observed:
  • only first user turn is processed and returned before process exits

Fixture files

• pixel.png (1x1 PNG)
• sample.pdf (tiny synthetic PDF)

The NDJSON repro inputs reference these files via file:///tmp/amp-repro-share/... paths.

amp-version.txt

0.0.1774471707-g40b89f

echo-document.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d276c-de8a-764d-98dd-565775031f66","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"result","subtype":"error_during_execution","duration_ms":5,"is_error":true,"num_turns":0,"error":"Invalid message format on stdin line 1: message.content.1: Invalid input","session_id":"T-019d276c-de8a-764d-98dd-565775031f66"}

echo-image-source-only.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d276c-c963-72ff-8fe1-4c175f4604df","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo image source: reply ECHO-IMAGE-SOURCE-OK"}]},"parent_tool_use_id":null,"session_id":"T-019d276c-c963-72ff-8fe1-4c175f4604df"}
{"type":"result","subtype":"error_during_execution","duration_ms":1816,"is_error":true,"num_turns":0,"error":"Agent failed to complete the request.","session_id":"T-019d276c-c963-72ff-8fe1-4c175f4604df"}

echo-image-source-path.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d276c-baed-722f-89cd-e72fce17b3dc","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"result","subtype":"error_during_execution","duration_ms":6,"is_error":true,"num_turns":0,"error":"Invalid message format on stdin line 1: message.content.1: Invalid input","session_id":"T-019d276c-baed-722f-89cd-e72fce17b3dc"}

ECHO-REPROS.md

Echo-pipe repros

All commands use this shape:

• echo '{...}' | amp --execute --stream-json --stream-json-input --stream-json-thinking

Included files:

• run-echo-repros.sh
• echo-text.out.ndjson
• echo-image-source-path.out.ndjson
• echo-image-source-only.out.ndjson
• echo-document.out.ndjson
• echo-two-turn-immediate.out.ndjson
• echo-two-turn-delayed.out.ndjson

Observed summary:

• Text-only succeeds.
• image with source_path fails input validation (Invalid input).
• image with inline base64 reaches execution then fails (Agent failed to complete the request.).
• document with source_path+base64 fails input validation (Invalid input).
• Two user lines in one stdin stream are collapsed/handled as one turn (num_turns: 1), both immediate and delayed variants.

echo-text.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d276c-a105-7679-926d-e0c4ac8e5616","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo baseline: reply ECHO-TEXT-OK"}]},"parent_tool_use_id":null,"session_id":"T-019d276c-a105-7679-926d-e0c4ac8e5616"}
{"type":"assistant","message":{"type":"message","role":"assistant","content":[{"type":"thinking","thinking":"The user wants me to reply with \"ECHO-TEXT-OK\"."},{"type":"text","text":"ECHO-TEXT-OK"}],"stop_reason":"end_turn","usage":{"input_tokens":10,"cache_creation_input_tokens":15767,"cache_read_input_tokens":18008,"output_tokens":32,"max_tokens":300000,"service_tier":"standard"}},"parent_tool_use_id":null,"session_id":"T-019d276c-a105-7679-926d-e0c4ac8e5616"}
{"type":"result","subtype":"success","duration_ms":2742,"is_error":false,"num_turns":1,"result":"ECHO-TEXT-OK","session_id":"T-019d276c-a105-7679-926d-e0c4ac8e5616"}

echo-two-turn-delayed.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d276d-09a5-743c-bcfb-fad830cc80d6","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo delayed turn1: reply D1"}]},"parent_tool_use_id":null,"session_id":"T-019d276d-09a5-743c-bcfb-fad830cc80d6"}
{"type":"assistant","message":{"type":"message","role":"assistant","content":[{"type":"thinking","thinking":"The user seems to be sending a test or debug message. This looks like it might be part of a testing framework or automated message. Let me respond appropriately."},{"type":"text","text":"It looks like you're sending a test/debug message (\"Echo delayed turn1: reply D1\"). How can I help you with your project?"}],"stop_reason":"end_turn","usage":{"input_tokens":10,"cache_creation_input_tokens":15941,"cache_read_input_tokens":0,"output_tokens":74,"max_tokens":300000,"service_tier":"standard"}},"parent_tool_use_id":null,"session_id":"T-019d276d-09a5-743c-bcfb-fad830cc80d6"}
{"type":"result","subtype":"success","duration_ms":3712,"is_error":false,"num_turns":1,"result":"It looks like you're sending a test/debug message (\"Echo delayed turn1: reply D1\"). How can I help you with your project?","session_id":"T-019d276d-09a5-743c-bcfb-fad830cc80d6"}

echo-two-turn-immediate.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d276c-ed57-70bb-8ff9-a6498858ef0a","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo turn1: reply E1"}]},"parent_tool_use_id":null,"session_id":"T-019d276c-ed57-70bb-8ff9-a6498858ef0a"}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo turn2: reply E2"}]},"parent_tool_use_id":null,"session_id":"T-019d276c-ed57-70bb-8ff9-a6498858ef0a"}
{"type":"assistant","message":{"type":"message","role":"assistant","content":[{"type":"thinking","thinking":"The user seems to be testing me with echo commands. They want me to echo back their messages.\n\nTurn 1: \"reply E1\"\nTurn 2: \"reply E2\""},{"type":"text","text":"reply E1\n\nreply E2"}],"stop_reason":"end_turn","usage":{"input_tokens":10,"cache_creation_input_tokens":15894,"cache_read_input_tokens":0,"output_tokens":58,"max_tokens":300000,"service_tier":"standard"}},"parent_tool_use_id":null,"session_id":"T-019d276c-ed57-70bb-8ff9-a6498858ef0a"}
{"type":"result","subtype":"success","duration_ms":3525,"is_error":false,"num_turns":1,"result":"reply E1\n\nreply E2","session_id":"T-019d276c-ed57-70bb-8ff9-a6498858ef0a"}

pixel.png.b64

iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO2N+HkAAAAASUVORK5CYII=

repro-document.ndjson

{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Please acknowledge the document and reply DOC-OK"},{"type":"document","source_path":"file:///tmp/amp-repro-share/sample.pdf","source":{"type":"base64","media_type":"application/pdf","data":"JVBERi0xLjQKMSAwIG9iago8PCAvVHlwZSAvQ2F0YWxvZyA+PgplbmRvYmoKdHJhaWxlcgo8PCAvUm9vdCAxIDAgUiA+PgolJUVPRgo="}}]}}

repro-document.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d275f-225d-70e2-9372-ab09150de424","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"result","subtype":"error_during_execution","duration_ms":6,"is_error":true,"num_turns":0,"error":"Invalid message format on stdin line 1: message.content.1: Invalid input","session_id":"T-019d275f-225d-70e2-9372-ab09150de424"}

repro-image-source-only.ndjson

{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Please acknowledge image and reply IMAGE-SOURCE-OK"},{"type":"image","source":{"type":"base64","media_type":"image/png","data":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO2N+HkAAAAASUVORK5CYII="}}]}}

repro-image-source-only.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d275f-3dc2-733b-866d-9f4d9f7f3f2d","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Please acknowledge image and reply IMAGE-SOURCE-OK"}]},"parent_tool_use_id":null,"session_id":"T-019d275f-3dc2-733b-866d-9f4d9f7f3f2d"}
{"type":"result","subtype":"error_during_execution","duration_ms":1403,"is_error":true,"num_turns":0,"error":"Agent failed to complete the request.","session_id":"T-019d275f-3dc2-733b-866d-9f4d9f7f3f2d"}

repro-image-source-path.ndjson

{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Please acknowledge the image and reply IMAGE-PATH-OK"},{"type":"image","source_path":"file:///tmp/amp-repro-share/pixel.png"}]}}

repro-image-source-path.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d275f-2f99-742b-9025-a58e9b2c1387","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"result","subtype":"error_during_execution","duration_ms":8,"is_error":true,"num_turns":0,"error":"Invalid message format on stdin line 1: message.content.1: Invalid input","session_id":"T-019d275f-2f99-742b-9025-a58e9b2c1387"}

repro-two-turn-delayed.out.ndjson

{"type":"system","subtype":"init","cwd":"/Users/georgios/github/paradigmxyz/centaur","session_id":"T-019d275f-5330-7326-8c73-f6066e8731b4","tools":["Bash","chart","create_file","edit_file","find_thread","finder","glob","Grep","handoff","librarian","look_at","mcp__dev_euw_grafana_tempo__docs_traceql","mcp__dev_euw_grafana_tempo__get_attribute_names","mcp__dev_euw_grafana_tempo__get_attribute_values","mcp__dev_euw_grafana_tempo__get_trace","mcp__dev_euw_grafana_tempo__traceql_metrics_instant","mcp__dev_euw_grafana_tempo__traceql_metrics_range","mcp__dev_euw_grafana_tempo__traceql_search","mermaid","oracle","painter","Read","read_mcp_resource","read_thread","read_web_page","skill","Task","task_list","undo_edit","web_search"],"mcp_servers":[{"name":"dev-euw-grafana-tempo","status":"connected"},{"name":"perfnet-grafana","status":"reconnecting"},{"name":"ai","status":"reconnecting"}]}
{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Delayed Turn 1: reply D1"}]},"parent_tool_use_id":null,"session_id":"T-019d275f-5330-7326-8c73-f6066e8731b4"}
{"type":"assistant","message":{"type":"message","role":"assistant","content":[{"type":"thinking","thinking":"The user sent a very brief message \"Delayed Turn 1: reply D1\". This seems like a test message or a placeholder. Let me respond concisely."},{"type":"text","text":"Got it — ready for your request. What would you like me to help with?"}],"stop_reason":"end_turn","usage":{"input_tokens":10,"cache_creation_input_tokens":15766,"cache_read_input_tokens":18008,"output_tokens":63,"max_tokens":300000,"service_tier":"standard"}},"parent_tool_use_id":null,"session_id":"T-019d275f-5330-7326-8c73-f6066e8731b4"}
{"type":"result","subtype":"success","duration_ms":4867,"is_error":false,"num_turns":1,"result":"Got it — ready for your request. What would you like me to help with?","session_id":"T-019d275f-5330-7326-8c73-f6066e8731b4"}

repro-two-turn-delayed.sh

#!/usr/bin/env bash
set -euo pipefail
{
  echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Delayed Turn 1: reply D1"}]}}'
  sleep 5
  echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Delayed Turn 2: reply D2"}]}}'
} | amp --execute --stream-json --stream-json-input --stream-json-thinking

run-echo-repros.sh

#!/usr/bin/env bash
set -euo pipefail

WORK=/tmp/amp-repro-share/echo-cases
mkdir -p "$WORK"

# text baseline
(echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo baseline: reply ECHO-TEXT-OK"}]}}' | amp --execute --stream-json --stream-json-input --stream-json-thinking) > "$WORK/echo-text.out.ndjson"

# image source_path
(echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo image path: reply ECHO-IMAGE-PATH-OK"},{"type":"image","source_path":"file:///tmp/amp-repro-share/pixel.png"}]}}' | amp --execute --stream-json --stream-json-input --stream-json-thinking) > "$WORK/echo-image-source-path.out.ndjson"

# image source only
(echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo image source: reply ECHO-IMAGE-SOURCE-OK"},{"type":"image","source":{"type":"base64","media_type":"image/png","data":"iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO2N+HkAAAAASUVORK5CYII="}}]}}' | amp --execute --stream-json --stream-json-input --stream-json-thinking) > "$WORK/echo-image-source-only.out.ndjson"

# document source_path+base64
(echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo document: reply ECHO-DOC-OK"},{"type":"document","source_path":"file:///tmp/amp-repro-share/sample.pdf","source":{"type":"base64","media_type":"application/pdf","data":"JVBERi0xLjQKMSAwIG9iago8PCAvVHlwZSAvQ2F0YWxvZyA+PgplbmRvYmoKdHJhaWxlcgo8PCAvUm9vdCAxIDAgUiA+PgolJUVPRgo="}}]}}' | amp --execute --stream-json --stream-json-input --stream-json-thinking) > "$WORK/echo-document.out.ndjson"

# two-turn immediate
({
  echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo turn1: reply E1"}]}}'
  echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo turn2: reply E2"}]}}'
} | amp --execute --stream-json --stream-json-input --stream-json-thinking) > "$WORK/echo-two-turn-immediate.out.ndjson"

# two-turn delayed
({
  echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo delayed turn1: reply D1"}]}}'
  sleep 5
  echo '{"type":"user","message":{"role":"user","content":[{"type":"text","text":"Echo delayed turn2: reply D2"}]}}'
} | amp --execute --stream-json --stream-json-input --stream-json-thinking) > "$WORK/echo-two-turn-delayed.out.ndjson"

for out in "$WORK"/*.out.ndjson; do
  echo "=== $(basename "$out") ==="
  jq -c 'select(.type=="result")' "$out" | tail -n 1
  echo
done

sample.pdf.b64

JVBERi0xLjQKMSAwIG9iago8PCAvVHlwZSAvQ2F0YWxvZyA+PgplbmRvYmoKdHJhaWxlcgo8PCAvUm9vdCAxIDAgUiA+PgolJUVPRgo=